Energy Efficiency Code for New Federal Residential Buildings

SUMMARY: The Department of Energy today proposes a rule that would

establish minimum energy-efficiency building standards for new Federal

residential buildings, including single-family and multi-family low-

rise housing, pursuant to the requirements of the Energy Conservation

and Production Act of 1976, as amended. The proposed rule would cover

all aspects of residential building thermal envelopes, including

foundations, crawl spaces, floors, walls, fenestration, roof/ceilings,

and attics. The proposed rule would also cover the heating,

ventilation, and air-conditioning systems design, service water heating

systems, radon control, air infiltration, and electrical power and

lighting systems. The proposed rule would revise the current Federal

residential standards to conform generally with the format and language

of the Council of American Building Officials Model Energy Code, 1992.

The proposed rule is, on the average, 11 percent more energy-efficient

than the Model Energy Code, 1992 for single-family residences and 26

percent more energy-efficient than the Model Energy Code, 1992 for

multi-family residences for heating and cooling.

DATES: Written comments on the proposed rule (ten copies and, if

possible, a computer disk containing the electronic file of these

comments) must be received on or before July 14, 1997. A public hearing

will be held in Washington, D.C., on June 5, 1997, beginning at 9:30

a.m. at the address listed below. Requests to speak must be received by

the Department on or before June 3, 1997. Ten copies of the statement

to be given at the public hearing must be received by the Department by

4:00 p.m., June 3, 1997.

ADDRESSES: Written comments on the proposed rule (ten copies), as well

as requests to speak at the public hearing, requests for copies of the

technical support documents and requests for speaker lists should be

addressed to: U.S. Department of Energy, Energy Efficiency Code for

Federal Residential Buildings, Docket Number EE-RM-96-300, Office of

Codes and Standards, Office of Energy Efficiency and Renewable Energy,

U.S. Department of Energy, Room 1J-018, 1000 Independence Avenue, S.W.,

Washington, D.C. 20585-0121, (202) 586-7574.

Fax comments will not be accepted. The public hearing will be held

at the U.S. Department of Energy, Forrestal Building, Room 1E-245, 1000

Independence Avenue, S.W., Washington D.C. 20585-0121. Copies of the

transcripts of the public hearings and written public comments received

may be read at the Department of Energy's Freedom of Information

Reading Room, U.S. Department of Energy, Forrestal Building, Room 1E-

190, 1000 Independence Avenue, S.W., Washington, D.C. 20585-0121, (202)

586-6020, between the hours of 9:00 a.m. and 4:00 p.m., Monday through

Friday, except Federal holidays. The reference standards are also

available from the sources listed in Subpart H of the proposed rule.

For more information concerning public participation see section IX.

Public Comment Procedures.

FOR FURTHER INFORMATION CONTACT:

Stephen P. Walder, Office of Codes and Standards, EE-43, U.S.

Department of Energy, Office of Energy Efficiency and Renewable Energy,

Room 1J-018, 1000 Independence Avenue, S.W., Washington, D.C. 20585-

0121, (202) 586-9209;

Francine B. Pinto, Esq., Office of General Counsel, GC-72, U.S.

Department of Energy, Room 6E-042, 1000 Independence Avenue, S.W.,

Washington, D.C. 20585-0103, (202) 586-7432.

SUPPLEMENTARY INFORMATION:

I. Introduction

A. Authority

B. Background

1. Model Energy Code, 1992

2. The Current Federal Standards

3. Standard 90.2-1993

II. Relationship Between the Proposed Rule, the MEC, 1992, the Current

Federal Residential Standards, Standard 90.2-1993, and Other Federal

Initiatives

A. General

B. Relationship Between the Proposed Rule and the MEC, 1992

C. Relationship Between the Proposed Rule and the Current Federal

Residential Standards

D. Relationship Between the Proposed Rule and Standard 90.2-1993

E. Relationship to Other Federal Initiatives

III. Description of the Proposed Rule and Differences Between the

Proposed Rule and the Model Energy Code, 1992

A. Subpart A: Administration and Enforcement

1. Sections 435.102.1.2 and 435.102.1.3: Building Envelope

Insulation and Insulation Installation

2. Section 435.102.3: Fenestration Product Rating,

Certification, and Labeling

3. Section 435.104: [Reserved]

4. Section 435.105: [Reserved]

5. Section 435.106: [Reserved]

6. Section 435.107: Precedence

7. Section 435.108: Life-Cycle Cost Analysis

B. Subpart B: Definitions

C. Subpart C: Design Conditions

D. Subpart D: Design by Systems Analysis; Design Utilizing Renewable

Energy Sources

1. Section 435.402.1: Energy Analysis

2. Section 435.402.1.1: Input Values/Assumptions for Group R

(Single Family and Multi-family Low Rise) Buildings

3. Section 435.403.3: Passive Solar Design Analysis

E. Subpart E: Design by Component Performance Approach

1. Major Revisions from the Model Energy Code, 1992 that are

Contained in Subpart E of the Proposed Rule

a. Section 435.502: Building Thermal Envelope Requirements

b. Section 435.502.2.1.1.2: Metal Framing

c. Section 435.502.2.1.5: Crawl Space Walls

d. Section 435.502.3.3: Recessed Lighting Fixtures

e. Section 435.503.2: Mechanical Equipment Efficiency

f. Section 435.503.3.1.1: Heating and Cooling Equipment Capacity

g. Section 435.503.5.7.2: Duct Sealing

h. Section 435.503.5.9.1: Backdrafting Test

i. Section 435.504.2: Service Water Heating Equipment

j. Section 435.504.4: Heat Traps

2. Miscellaneous Revisions that are Contained in Subpart E of

the Proposed Rule, Not in the MEC, 1992

F. Subpart F: [Reserved]

G. Subpart G: Radon Control

H. Subpart H: Standards

IV. Consultation

V. Energy and Economic Impacts

VI. Technological Feasibility and Economic Justification

VII. Measures Concerning Radon and Other Indoor Air Pollutants

VIII. Findings and Certification

A. Review Under the National Environmental Policy Act

B. Environmental Protection Agency Review

C. Regulatory Planning and Review

D. Federalism Review

E. Review Under Executive Order on Metric Usage in Federal

Government Programs

F. Review Under Executive Order on Civil Justice Reform

G. Review Under the Regulatory Flexibility Act

H. Paperwork Reduction Act Review

[[Page 24165]]

I. Review Under Section 32 of the Federal Energy Administration

Authorization Act

J. Unfunded Mandates Reform Act Review

IX. Public Comment Procedures

A. Participation in Rulemaking

B. Solicitation of Public Comments

C. Written Comment Procedures

D. Public Hearings

1. Procedure for Submitting Requests to Speak

2. Conduct of Hearings

I. Introduction

A. Authority

The Department today proposes a rule that would establish Federal

building energy-efficiency standards for new Federal residential

buildings pursuant to section 305(a) of the Energy Conservation and

Production Act (ECPA), as amended by the Energy Policy Act of 1992

(EPACT), 42 U.S.C. 6834(a). In developing this proposed rule, the

Department is directed to consult with other Federal agencies as well

as private and state associations and other appropriate persons.

Section 305(a)(1) of the ECPA requires the Department to establish

Federal building energy standards that include those energy-efficiency

measures that are technologically feasible and economically justified.

The standards must contain energy saving and renewable energy

specifications that meet or exceed the energy saving and renewable

energy specifications of the Council of American Building Officials

(CABO) Model Energy Code (MEC), 1992. Section 305(a)(2)(A).

Section 305(a)(2)(B) requires that to the extent practicable, the

proposed standards use the same format as the appropriate voluntary

building energy code, in this case, the MEC, 1992. Furthermore, Section

305(a)(2)(C) requires that the proposed rule be established in

consultation with the Environmental Protection Agency (EPA) and other

Federal agencies and, where appropriate, contain measures with regard

to radon and other indoor air pollutants.

The current energy performance standards for new Federal buildings

remain in effect until the standards established under subsection (a)

become effective. Section 305(d). These current standards are found in

10 CFR Part 435, Subpart C.

Section 306 addresses Federal compliance. Each Federal agency and

the Architect of the Capitol must adopt procedures to assure that new

Federal buildings will meet or exceed the Federal building energy

standards proposed here. Section 306(a). Section 306(b) bars the head

of a Federal agency from expending Federal funds for the construction

of a new Federal building unless the building meets or exceeds the

appropriate Federal building energy standards established under Section

305.

B. Background

There are currently three building energy codes that address low-

rise residential buildings in all parts of the United States \1\: the

Model Energy Code (MEC); 10 CFR Part 435, Subpart C, Mandatory

Performance Standards for New Federal Residential Buildings; and the

American Society of Heating, Refrigerating and Air Conditioning

Engineers (ASHRAE), Inc., Standard 90.2-1993, Energy-Efficient Design

of New Low-Rise Residential Buildings. All three bear on today's

proposed rule. The MEC contributes format, substance, and technical

improvements to the proposal. The Federal residential standards first

introduced the concept of cost-effectiveness in building standards and

tools to analyze the economic justification of energy-efficiency

requirements in building standards. Tools that evolved from the

development of the current Federal residential standards were used to

determine the economic justification for the requirements contained in

the proposed rule. ASHRAE Standard 90.2-1993 also provides substantive

technical improvements to the proposal.

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\1\ There are other building energy codes that are state-

specific or regional that are not considered.

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1. Model Energy Code, 1992

Currently, the MEC is the most widely accepted and used residential

energy-efficiency code in the United States. Seventeen states have

adopted the MEC, or modified versions of the MEC, as their energy code.

Approximately 20 percent of new home loans are issued or guaranteed by

the Department of Housing and Urban Development, the Department of

Veterans Affairs, and the Rural Economic and Community Development

group of the Department of Agriculture. Such loans or loan guarantees

require compliance with the MEC, 1992. The MEC has been promulgated

jointly by the three model code organizations: the Building Officials

and Code Administrators International; the International Conference of

Building Officials; and the Southern Building Code Congress

International under the auspices of the Council of American Building

Officials. The MEC is provided as a model and intended for adoption by

state and local jurisdictions.

The provisions of the MEC, 1992 regulate the design of building

envelopes for adequate thermal resistance and low air leakage and the

design and selection of mechanical, electrical, service water-heating

and illumination systems and equipment which will enable effective use

of energy in new building construction. The MEC provides flexibility to

permit the use of innovative approaches and techniques to achieve

efficient utilization of energy. These provisions are structured to

permit compliance with the intent of the code by any one of the

following paths of design: (1) A systems analysis approach for the

entire residential building and its energy-using subsystems, including

buildings which utilize renewable sources (Chapter 4), (2) a building

design by component performance approach (Chapter 5) and, (3) building

design by acceptable practice (Chapter 6).

2. The Current Federal Standards

On August 25, 1988, the Department published standards for new

Federal residential buildings (53 FR 32536). It established building

energy-efficiency standards for the design and construction of Federal

residential buildings.

The current Federal standards require that Federal agencies use

software to create project-specific compliance forms that are then

completed by prospective builders to demonstrate compliance with

minimum energy-efficiency requirements. The process must be undertaken

for each project. The micro-computer software program, Conservation

Optimization Standard for Savings in Federal Residences (COSTSAFR),

uses local construction, maintenance and replacement costs, local

climate data, and local fuel costs to determine an energy-efficient and

cost-effective energy usage goal for any of nine residential building

unit types addressed in the COSTSAFR program data base. COSTSAFR

calculates project-specific minimum energy-efficiency requirements and

presents these requirements in compliance forms known as ``the point

system.'' The use of COSTSAFR eliminated the need for performing

lengthy calculations or making uninformed choices regarding the

selection of energy-efficiency measures. COSTSAFR is designed so that

implementing officials, designers, and builders can easily tell if a

proposed combination of measures will result in energy-efficiency

levels that meet or

[[Page 24166]]

exceed the COSTSAFR required level for cost-effective energy-efficiency

in a building.

The Department decided not to use COSTSAFR as the basis for this

new Federal proposed rule because it cannot always be assured of

complying with the new legislative requirements. In particular,

COSTSAFR can generate energy-efficiency requirements that do not meet

the MEC, 1992 energy-efficient levels specified by EPACT. The software

would have to be reconfigured to eliminate this possibility.

3. Standard 90.2-1993

Standard 90.2-1993, Energy-Efficient Design of New Low-Rise

Residential Buildings, is a standard for residential construction

published by the American Society of Heating, Refrigerating and Air

Conditioning Engineers (ASHRAE), Inc. Standard 90.2-1993 is the next

generation residential component of ASHRAE's earlier Standard 90 (1975)

and Standard 90A-1980, which specified design requirements for energy-

efficient commercial and residential buildings. Standard 90.2-1993 sets

criteria for the building envelope, heating equipment and systems, air-

conditioning and systems, and provisions for overall building design

alternatives and trade-offs.

II. Relationship Between the Proposed Rule, the MEC, 1992, the Current

Federal Residential Standards, Standard 90.2-1993, and Other Federal

Initiatives

A. General

The Department has decided to develop a proposed rule similar in

format to the MEC rather than modify the current Federal residential

building standards. Currently, construction professionals are more

familiar with the MEC, 1992 format and content than the Federal

standards. This familiarity with the MEC requirements and format is

likely to reduce costs associated with the development and use of

building specifications consistent with those of the MEC. The

consistency of the proposed rule with industry-wide practice will

facilitate implementation by Federal agencies of the final rule.

Currently, 10 CFR Part 435 contains standards for Federal commercial

buildings (Subpart A), a reserved section that was intended for

voluntary standards for new non-Federal residential buildings (Subpart

B), and standards for Federal residential buildings (Subpart C). On

August 6, 1996, the Department proposed to remove Subpart A from Part

435 and republish it as a new Part 434 in the Code of Federal

Regulations. (61 FR 40882). In today's proposed rule, Subparts B and C

would be removed and Part 435 would be revised to establish standards

for Federal residential buildings only.

B. Relationship Between the Proposed Rule and the MEC, 1992

The proposed rule would adopt portions of the Model Energy Code,

1992 verbatim. There are, however, some requirements in the proposed

rule that exceed the MEC, 1992 resulting in increased energy-

efficiency. Many of the provisions improving energy-efficiency are

found in the 1993 and 1995 versions or the 1994 amendments to the MEC,

1993. Those aspects of the proposed rule that exceed the MEC, 1992

resulting in increased energy-efficiency are: (1) more stringent

thermal envelope requirements, (2) insulating of crawl space walls, (3)

sealing recessed light fixtures, (4) heating and cooling equipment

capacity requirements, (5) air distribution system construction, and

(6) heat traps.

The proposed rule would also make revisions to the Model Energy

Code, 1992, that are consistent with current building construction

practice. These include requirements for: (1) insulation inspection,

(2) window and door thermal performance ratings, (3) improved

performance path specifications, (4) metal framing construction and,

(5) radon and other indoor air pollutants. The requirements referenced

in (1)-(4) above, do not save energy but help ensure that energy

savings are achieved. Requirements concerning radon and other indoor

air pollutants are consistent with health and safety needs.

Further, the Department has made miscellaneous minor changes to the

MEC, 1992 to improve the clarity and useability of the rule. These

miscellaneous changes are not expected to have any impact on the

agencies or their contractors.

The proposed rule is on the average, 11 percent more energy-

efficient than the Model Energy Code, 1992 for single-family residences

and 26 percent more energy-efficient than the Model Energy Code, 1992

for multi-family residences for heating and cooling.

C. Relationship Between the Proposed Rule and the Current Federal

Residential Standards

There are significant differences and similarities between the

proposed rule and the current standards. The current standards have a

point system related to energy cost that permits tradeoffs among

energy-efficiency measures, while the proposed rule has an overall U-

value that permits tradeoffs in envelope measures. The use of

microcomputer software is necessary to determine the requirements of

the current standards, whereas, the requirements of the proposed rule

are contained in a hardcopy publication. Both have a similar whole

building energy usage analysis compliance approach.

The current Federal standards will not always assure the user of

meeting or exceeding the requirements of the MEC, 1992. The Department

has demonstrated that residential buildings designed using COSTSAFR

will have a less stringent level of thermal performance than those

buildings designed using the requirements of the proposed rule.

D. Relationship Between the Proposed Rule and Standard 90.2-1993

A number of features from Standard 90.2-1993 are included in

today's proposed rule. These provisions address feasible residential

design features not presently or adequately addressed by the MEC, while

providing the potential for further energy savings in the proposed

rule. They include heating and cooling equipment sizing limitations;

default thermal performance data for metal frame walls; and heat traps

on water heaters for potable water.

Standard 90.2-1993 has been put into code format providing a

similar structure for both the standard and the proposed rule. Both

also have three alternative compliance paths of similar nature.

Standard 90.2-1993 however, has more complexity than the respective

compliance options of the proposed rule. The Department believes that

this greater complexity of Standard 90.2-1993 would make it more

difficult to adopt, use, and enforce than the MEC, which is the basis

for the proposed rule. The Department also believes that the complexity

and differences between Standard 90.2-1993 and the MEC would have made

it difficult for the Department to have assured the user of meeting the

minimum energy-efficiency requirements of the MEC, 1992. The Department

determined that the necessary cost and resources to revise Standard

90.2-1993 as the proposed Federal residential rule and that would meet

or exceed the MEC, 1992 would not be warranted. The proposed rule looks

to the broad recognition and penetration enjoyed by the MEC within the

community of residential designers, builders and enforcement officials

to facilitate its implementation by the Federal sector.

[[Page 24167]]

E. Relationship to Other Federal Initiatives

The proposed rule would establish the minimum level of energy-

efficiency for new Federal buildings. The rule works in conjunction

with two related Federal initiatives designed to encourage cost-

effective efficiency improvements for new buildings beyond the minimum

requirements of the proposed rule. First, Executive Order on Energy

Efficiency and Water Conservation at Federal Facilities, Executive

Order No. 12902 (59 FR 11463, March 8, 1994), specifically requires

that, ``Each agency involved in the construction of a new facility--

shall: (1) design and construct such facility to minimize the life

cycle cost of the facility by utilizing energy efficiency, water

conservation, or solar or other renewable energy technologies.''

Section 306(a) of Executive Order 12902. It also requires agencies to

``ensure that the design and construction of facilities meet or exceed

the energy performance standards applicable to Federal residential or

commercial buildings as set forth in 10 CFR Part 435, local building

standards, or a Btu-per-gross square-foot ceiling--whichever will

result in a lower life cycle cost over the life of the facility.''

Section 306(a)(2) of Executive Order 12902. In addition, Federal

agencies shall increase, to the extent practicable and cost-effective,

purchases of products that are in the upper 25 percent of energy

efficiency for all similar products, or products that are at least 10

percent more efficient than the minimum level that meets Federal

standards. Section 507(a)(2) of Executive Order 12902. This latter

provision is being implemented through the Department's ``Procurement

Challenge Program'' that notifies Federal agencies of the availability

and performance of these high-efficiency options. This ``Procurement

Challenge Program'' is being coordinated with the EPA ``Energy Star''

product specification activities. In addition, the Department's Office

of Building Technologies, State and Community Programs provides

detailed technical information on state-of-the-art energy-efficiency

equipment for new buildings. These sources of technical assistance can

help Federal agencies specify highly-efficient equipment for new

Federal residential buildings.

Second, section 435.108 of today's proposed rule references the

requirements of 10 CFR Part 436 governing life-cycle cost analysis for

Federal energy investments. The life-cycle cost analysis provisions

found in 10 CFR Part 436 allow agencies to determine when additional or

alternate energy-efficiency measures would provide net benefits in the

form of energy cost savings to ensure that measures selected are cost-

effective to the Federal government. This is especially relevant in

areas where energy costs are higher than presumed for the analysis

supporting today's proposal, and for innovative technologies and

specifications that cannot be readily incorporated into the proposed

rule. The microcomputer program entitled ``ARES'' (Automated

Residential Energy Standard) can be used for evaluating the life-cycle

cost-effectiveness of various thermal envelope energy-efficiency

measures (EEMs) that can be more energy-efficient than the requirements

of the proposed rule. The Department is currently conducting life-cycle

cost analysis that would identify energy-efficiency measures that are

economically justified in specified circumstances and exceed the

minimum requirements of the proposed rule. The Department will provide

the results of this analysis to the Federal agencies to assist them in

the design and construction of energy-efficient Federal residential

buildings.

III. Description of the Proposed Rule and Differences Between the

Proposed Rule and the Model Energy Code, 1992

This section describes the proposed rule and the differences

between the proposed rule and the Model Energy Code, 1992. Those

sections of the proposed rule not specifically addressed here have been

adopted from the MEC, 1992. Minor language and citation changes will

not be noted. The discussion below corresponds to the subparts,

sections, paragraphs, and subparagraphs in the proposed rule. The

sections identified as reserved are discussed briefly.

A. Subpart A: Administration and Enforcement

This subpart describes the scope and general requirements of the

rule, the requirements concerning the identification and maintenance

information on building materials and equipment, the use of alternate

materials, the application of the proposed rule if sections are in

conflict, and the requirement for a life-cycle cost analysis.

Proposed sections 435.101-108 contain changes from the MEC, 1992,

as discussed below. The Department believes that the provisions

discussed below are technologically feasible, and are of such minimal

cost that the benefits of such requirements make them economically

justified.

1. Sections 435.102.1.2 and 435.102.1.3: Building Envelope Insulation

and Insulation Installation

The sections require that insulation installed in the building be

clearly marked so that the ``R-value'' of the insulation can be easily

verified. The blown or sprayed attic insulation ``depth'' marker

requirement is contained in the MEC, 1995 but not in the MEC, 1992. The

insulation depth markers will help ensure that the claimed thickness of

the loose-fill ceiling insulation can be verified. Verification of the

ceiling insulation assures that the designed energy-efficiency

performance of the building ceiling can be achieved at a minimal cost

to the government. The associated costs are minimal compared to the

possibility of installing insulation that is less than the required

designed thickness and thereby loses energy. The use of depth markers

is technologically feasible because a marker is a simple ruler

graduated in one-inch increments and affixed to the roof/ceiling

framing.

2. Section 435.102.3: Fenestration Product Rating, Certification, and

Labeling

Section 121 of EPACT requires the Secretary of Energy to make a

determination, within one year of enactment, on whether a window energy

rating and labeling program established by the National Fenestration

Rating Council (NFRC) meets the objectives of the legislation. If not,

the Department is to develop a mandatory rating program. The

Secretary's provisional determination concluded that the NFRC voluntary

national window rating program meets the requirements of EPACT.

(September 23, 1994, 59 FR 48865, 48868). The Department supports the

NFRC efforts to establish a uniform, national rating, certification and

labeling program through incorporation of the NFRC program in Federal,

state and local government and national voluntary codes and standards.

The verification of window and door assembly U-values is a

significant element in determining the overall U-value or thermal

performance of the building envelope, which is a key factor in

achieving compliance with the proposed rule. Section 435.102.3 of the

proposed rule requires that when Federal agencies purchase fenestration

products, the U-value (conductive heat transfer) for that fenestration

product (window, door, and skylight) shall be assigned. If the product

has been tested in accordance with NFRC 100-91 (Procedure for

Determining Fenestration

[[Page 24168]]

Product Thermal Properties), the NFRC U-value shall be used. The rating

procedure tests the fenestration products to determine the conductive

heat transfer properties and/or characteristics of the product.

If fenestration products are not tested in accordance with NFRC

100-91, a default U-value will be assigned, using Tables 102.3.1 and

102.3.2 located in the Appendix of the proposed rule. The default

values represent a conservative energy-efficiency performance potential

of a product based on characteristics of the product which are

verifiable by visual inspection. The NFRC 100-91 rating procedure and

the default U-value tables for non-tested products in the proposed rule

are those found in the MEC, 1995.

There is no standard for rating the energy-efficiency (U-values) of

window and door assemblies in the MEC, 1992. The inclusion of the

requirement to assign U-values to fenestration products will

potentially save energy costs by eliminating inaccurate U-values or

ratings that do not reflect the total window or door assembly thermal

performance. Thus assigning U-values or default U-values helps to

ensure that the claimed thermal performance of fenestration products

will actually be achieved in housing construction.

The NFRC procedure provides a fair and accurate rating of window

and door thermal performance. Over 22,000 products have been rated by

the NFRC. The ratings of window and door thermal performance are

recognized by at least six states in their building code provisions

regarding energy-efficiency.

Windows and doors that are rated in accordance with NFRC 100-91 may

result in an expenditure by the product manufacturer. However, NFRC

100-91 is set up so that every window or door unit need not be tested

individually. The results of a few actual tests are extrapolated by

computer modeling to the manufacturer's entire product line. Thus the

per unit cost of receiving a NFRC rating is relatively small.

Alternatively, a fenestration product manufacturer can elect not to

test and save the associated costs, and receive the default U-value

rating.

Assigning a U-value according to the new rating procedure can

change the rating received by particular windows. A model that was

previously rated at 0.4 might, for example, be rated under the new

system at 0.5. As a result, there may be situations in which agencies

would change the window selected in order to keep with the code's U-

value requirements. That change could result in higher purchase prices,

but would reduce building energy use as well. The use of energy-

efficient windows is becoming standard building construction practice

in most regions of the nation, particularly in the northern tier

states, indicating their general cost-effectiveness in today's building

markets. Given the nominal cost per unit for NFRC testing and rating

and the general cost-effectiveness of energy-efficient windows, the

Department has determined that the assigning of U-values in accordance

with NFRC 100-91 or default U-values in the proposed rule is

economically justified. See the Technical Support Document, section

6.7, page 6.6.

3. Section 435.104: [Reserved]

The proposed rule does not include the section entitled, ``Plans

and Specifications'' from the MEC, 1992.

4. Section 435.105: [Reserved]

The MEC, 1992 has requirements concerning the inspection by the

building official of construction or work for which a building permit

is required. Federal agencies have various procedures concerning the

inspection of construction. Section 435.105 is reserved in the proposed

rule to allow Federal agencies the flexibility of using their own

requirements concerning the inspection of residential construction.

5. Section 435.106: [Reserved]

The proposed rule does not include the section entitled,

``Validity'' from the MEC, 1992.

6. Section 435.107: Precedence

The Model Energy Code, 1992 contains no statement addressing the

order of precedence between potentially conflicting requirements of the

proposed code and those of a reference standard. Section 435.107.1 of

the proposed rule clarifies which requirements that shall apply.

7. Section 435.108: Life-Cycle Cost Analysis

The MEC, 1992 contains no requirements related to life-cycle costs.

The proposed rule would require building design(s) of Federal

residential buildings to be evaluated consistent with Subpart A of 10

CFR Part 436, which specifies methodologies and procedures for life-

cycle cost analyses of Federal buildings.

B. Subpart B: Definitions

This subpart includes definitions for all relevant words or phrases

that have a specific meaning within the context of the rule. In

accordance with the proposed rule, new definitions not in the MEC, 1992

have been added and unneeded definitions have been removed. For

example, definitions related to the radon control requirements have

been added and definitions related to non-residential HVAC systems and

components not regulated by this rule have been deleted. Appendix D in

the Technical Support Document identifies those definitions that have

been added or removed.

C. Subpart C: Design Conditions

This subpart gives sources for heating and cooling degree-day data,

establishes design conditions for the sizing of the heating,

ventilating, and air-conditioning system, and provides reference

standards for mechanical ventilation criteria. Other than identifying

cooling degree-days and providing more specific information on where

one may obtain weather data, this section is unchanged from the MEC,

1992.

D. Subpart D: Design by Systems Analysis; Design Utilizing Renewable

Energy Sources

This subpart contains a compliance approach that may be used as an

alternative to Subpart E. Subpart E contains the minimum energy-

efficiency requirements for the thermal performance of new Federal

residential buildings.

Subpart D requires that the user conduct an annual energy analysis.

It defines the general methodology and rules for this energy

comparison. A proposed building complies with this rule if its

calculated annual energy usage is less than or equal to the energy

usage of a similar building (referred to as the ``standard design'')

designed in accordance with Subpart E. The annual energy analysis

methodology is equivalent to that in Chapter 4 of MEC, 1992 but

provides more direction and specific detail on how the annual energy

analysis shall be conducted, as discussed below.

1. Section 435.402.1: Energy Analysis

A critical parameter for performing any comparative energy analysis

is defining the space heating, air conditioning, and service water

heating equipment and the efficiency or performance levels of that

equipment for the ``standard'' design.

As in the MEC, 1992, the proposed rule would require that the

standard and the proposed design be compared utilizing the ``same

energy source(s) for the same functions.'' These energy sources are

determined by the Subpart E provisions governing the selection of

equipment. This energy consumption provision is similar to the

provision in

[[Page 24169]]

section 402.1 contained in the MEC, 1992 and 1993. The only substantive

difference between the proposed rule and the earlier versions of the

MEC that relate to this section is the application of life-cycle cost

requirements.

In order to comply with Subpart D, a proposed design must be at

least as life-cycle cost-effective as the standard design and use no

more energy than the standard design. In the event that the proposed

design utilizes more than one energy source and increases the

consumption of one energy source and decreases the consumption of the

other energy source, then the overall energy consumption, measured at

the site, must be less than or equal to the standard design. Because

the energy sources in the standard and proposed design must be the

same, changes in energy consumption that affect more than one energy

source would be limited to variations in equipment efficiency and types

and building thermal envelope efficiencies.

Because methods for consistently measuring and comparing the energy

performance of new technologies take time to develop, the proposed

design may utilize newer equipment types not covered using current

Department test procedures. The Department is requesting comment on

methods of addressing newer equipment technologies for which a

recognized means of evaluating and comparing energy performance have

not yet been fully developed.

2. Section 435.402.1.1: Input Values/Assumptions for Group R (Single-

Family and Multi-family Low Rise) Buildings

This proposed rule specifies input values/assumptions for certain

energy-related building parameters that must be used in the whole

building energy analysis comparison. These values were taken from the

MEC, 1995. In contrast, the MEC, 1992 does not provide specification of

these values. For example, if the builder or designer chooses to use

the annual energy analysis approach, the thermostat set points that

must be assumed are given in Table 402.1.1-4, whereas the MEC, 1992

provides no information.

The specification of input values/assumptions performs two

functions. First, it eliminates the time and effort that each user

needs to set these values/assumptions individually. Second, it

establishes ground rules that ensure consistency among different whole

building annual energy analyses and helps prevent misuse of this

approach.

The Department has determined that specifying the input values/

assumptions to annual energy analyses comparisons is technologically

feasible because it is consistent with current building energy usage

analysis practice and is the only way to verify consistency in

analytical results across the different analytical tools. The

specification of input values is also economically justified since

failure to specify such input values could result in the approval of

noncomplying or unrealistic building designs and unnecessary energy

cost increases. The introduction of erroneous data would add

unwarranted time, effort, and cost to the project.

The Department has included many new annual energy analysis input

values/assumptions in the proposed rule. See the Technical Support

Document, section 6.8, page 6.8.

3. Section 435.403.3: Passive Solar Design Analysis

The MEC, 1992 and 1995 do not include direction on methodologies

for measuring the energy impacts of solar space conditioning. This

section of the proposed rule allows for the optional use of

``BuilderGuide,'' a software program that calculates heating and

cooling loads for solar technologies. ``BuilderGuide'' was produced by

the Department in partnership with the Passive Solar Industries Council

and the National Renewable Energy Laboratory. The resulting

``BuilderGuide'' package is specific to some 2400 United States

locations, and uses a methodology that is based on 15 years of solar

energy research. The Department has determined that ``BuilderGuide'' is

a well developed, widely distributed and recognized software program.

Other reliable tools for calculating energy usage of solar technologies

or other new energy-efficiency measures can be used. The Department

recognizes that designs using renewable energy sources for space

conditioning or water heating may be economically justified. The

Department is promoting ways to further stimulate the use of renewable

sources of energy. The Department welcomes additional suggestions on

approaches for crediting measures that use renewable sources of energy.

E. Subpart E: Design by Component Performance Approach

Sections 435.501-505 contain the minimum energy-efficiency

requirements for the thermal performance of building envelope

components, building mechanical systems and equipment, service water

heating, and electrical power and lighting. Compliance with the

requirements of Subpart E is required unless the optional compliance

approach prescribed in Subpart D is used.

The building envelope requirements apply to the building components

enclosing conditioned space, including: roof/ceilings, above grade

walls, slab-on-grade floors, floors over unconditioned spaces, basement

walls, crawl space walls, doors, windows, and skylights. The proposed

rule also contains requirements limiting air infiltration through the

building envelope.

The mechanical systems and equipment performance requirements set

heating and cooling equipment load capacity (sizing) limits,

temperature and humidity control requirements, distribution system

construction and insulation requirements, and backdrafting testing

requirements. The requirements relating to electrical power and

lighting systems apply only to multi-family residences. The mechanical

equipment section does not require mechanical equipment efficiencies

that exceed current Federal minimum standards.

Sections 435.501-505 of the proposed rule in Subpart E revise and

update the requirements contained in Chapter 5 of the MEC, 1992.

Subpart E contains two separate building envelope compliance

approaches. The two approaches are: (1) The individual component

performance approach and, (2) the whole building performance approach.

The individual component performance approach (section 435.502.2.1)

gives maximum U02 requirements for the floor over

unheated spaces, wall, and roof/ceiling. The different elements of the

wall (insulation, windows, doors, opaque wall), the floor (insulation,

type of floor), or the roof/ceiling (insulation, skylights, type of

ceiling) may be varied to achieve the U0. The whole building

performance approach (section 435.502.2.2) defines the maximum

U0 requirement for the entire building. The user can then

tradeoff among the requirements for the walls, floors, and roof/

ceilings as long as the maximum U0 for the entire building

is not exceeded.

---------------------------------------------------------------------------

\2\U0 = the area-weighted average thermal

transmittance of an area of the building envelope; i.e., the

exterior wall assembly including fenestration and doors, the roof

and ceiling assembly, and the floor assembly (British thermal unit/

(hour x square feet x degrees Fahrenheit).

---------------------------------------------------------------------------

1. Major Revisions From the Model Energy Code, 1992 That Are Contained

in Subpart E of the Proposed Rule

The major substantive changes from the MEC, 1992 as found in

Subpart E are described below.

a. Section 435.502: Building thermal envelope requirements. The

tables

[[Page 24170]]

found in proposed section 435.502, and Figures 1 through 6 in the

Appendix contain the building thermal envelope requirements. These

requirements are significantly changed from the MEC, 1992 and generally

are more stringent than the MEC, 1992, except for the requirements for

crawl space walls which are essentially the same as those in the MEC,

1992. The requirements that are more stringent than the MEC, 1992

consist of maximum U0-values for above-grade walls including

windows and doors, roof/ceilings, floors over unheated spaces, basement

walls, and minimum R-values for slab-on-grade perimeters. When

describing the thermal performance of a building component, consider

that the lower a U0-value, the more energy-efficient the

component and the higher a R-value, the more energy-efficient the

component.

The Department conducted a life-cycle cost economic analysis, as

specified at 10 CFR Part 436, to analyze these thermal envelope

requirements so as to minimize life-cycle costs to the Federal

government. The assessment was conducted using the ARES computer

software analyzing information such as the average Federal cost of

energy, expected energy price increases, and typical costs for

installation and maintenance of proposed measures. The economic

analysis considered construction-related costs and space heating and

cooling energy costs for 881 cities and eight types of common heating

fuel/equipment types. See the Technical Support Document (chapters 2

thru 5) for a detailed description of the analysis to establish the

building thermal envelope requirements.

b. Section 435.502.2.1.1.2: Metal framing. The proposed rule

includes a detailed new table (Appendix Table 502.2.1.1.2) to provide

users with the correction factors for the thermal-performance values of

wall assemblies framed with metal studs. Table 502.2.1.1.2 does not

appear in the MEC, 1992 but is in the MEC, 1995 and Standard 90.2-1993.

This table provides a standardized treatment of heat loss through walls

framed with metal studs. The thermal performance requirements of such

walls are the same as those for wood-framed walls. Metal framing is

technologically feasible. Metal wall assemblies have become more

popular over the last several years due in part to the price increase

of wood. Metal framing is not required by the rule and need not be

specified where not cost-effective or otherwise not preferred.

c. Section 435.502.2.1.5: Crawl space walls. Section 435.502.2.1.5

of the proposed rule requires floors above crawl spaces vented to

outdoors to be insulated. This requirement is contained in the MEC,

1995, but is not in the MEC, 1992. In the MEC, 1992 insulating the

crawl space wall was not dependent on whether the crawl space was

ventilated. Wall insulation for vented crawl spaces is ineffective

because outside air will enter the crawl space through the vents.

Increased energy usage results from the uninsulated heat transfer path

through the floor above. Crawl space wall insulation in the proposed

rule is an option only if the crawl space is not vented. The Department

has determined that the insulation of floors over vented crawl spaces

is technologically feasible since it is part of current standard

building construction practice.

Further, the requirement is economically justified. See the

Technical Support Document, section 6.3, page 6.2.

d. Section 435.502.3.3: Recessed lighting fixtures. Recessed

lighting fixtures, when installed in the building envelope, must be

properly sealed to prevent unwanted ceiling air leakage. The

requirement is contained in the MEC, 1995. Without this requirement,

recessed lighting fixtures can be a significant source of energy loss

due to air leakage into the attic space. The MEC, 1992 has no

requirements relating specifically to recessed lighting fixtures.

The Department has determined that the insulation and sealing of

recessed lighting fixtures are technologically feasible. These

practices are used in current building construction practice. The

requirement is economically justified because the incremental cost for

installing well-sealed recessed light fixtures is less than the cost of

the energy that would otherwise be lost over the 25-year analysis

period. See the Technical Support Document, section 6.6, page 6.5.

e. Section 435.503.2: Mechanical equipment efficiency. Section

435.503.2 addresses the selection of heating and cooling equipment with

attention to the use of life-cycle cost principles. The primary

difference between the MEC, 1992 and the proposed rule regarding this

section is that the proposed rule includes provisions addressing the

life-cycle cost of the installed equipment. The MEC, 1992 has no

requirements concerning life-cycle cost principles. In the proposed

rule when selecting among equipment options that are minimally

compliant with Federal performance standards, that option with the

lowest life-cycle cost is to be selected. The proposed rule allows for

the selection of equipment that exceeds Federal minimum efficiency

standards under Subpart E providing the equipment is at least as life-

cycle cost effective as equipment that is minimally compliant with

Federal standards. Agencies are encouraged through the Procurement

Challenge program and other Federal initiatives to consider more

energy-efficient equipment.

Given the large range of heating and cooling equipment types and

efficiencies available, this section provides a simplified method for

incorporating life-cycle cost principles into equipment selection. Two

options are provided for: the first option requires Federal agencies to

select the most cost-effective equipment that is minimally compliant

with Federal standards. For central heating and cooling equipment

systems for multi family dwellings that service multiple rather than

individual dwelling units, minimum equipment efficiencies found in the

codified version of ASHRAE Standard 90.1-1989 are used. This approach

is consistent with the overall rule, which sets building envelope

efficiency requirements at a level that is cost-effective on average

when equipment at minimum Federal efficiency levels is used. The second

option allows for the use of any other equipment available, provided

that it is at least as cost-effective as the heating and cooling

equipment identified under the first option. This second option allows

for the use of more efficient versions of equipment that are subject to

minimum Federal standards and would allow use of equipment, such as

natural gas heat pumps or ground source heat pumps, that are not

covered by the Federal standards.

It is anticipated that for most buildings, an informal comparison

of local costs and fuel availability will identify a few systems as the

most likely to be the most cost-effective; these systems can then be

compared in more detail to identify the system that has the lowest

life-cycle cost under the first option. If any other equipment is

preferred, a single additional calculation will establish whether it is

more cost-effective than the system identified in the first option.

f. Section 435.503.3.1.1: Heating and cooling equipment capacity.

The Department has included limits on equipment capacities in section

435.503.3.1.1 of the proposed rule. These requirements are taken from

the codified version of Standard 90.2-1993. The MEC, 1992 has no

requirements relating to the sizing of heating and cooling equipment.

Oversizing of heating and cooling equipment results in increased energy

usage since the equipment cycles on and off more frequently and,

therefore, runs at a

[[Page 24171]]

lower average efficiency than properly sized equipment. Furthermore,

oversized cooling equipment is less able to remove moisture from the

air and, therefore, is less able to control humidity. Also, oversized

heating, ventilating, and air-conditioning equipment also generally

costs more to purchase than properly sized equipment. The Department

believes that the requirement is technologically feasible and

economically justified based on the discussion above. See the Technical

Support Document, section 6.2, page 6.2. However, in very well

insulated homes, equipment sizing could be such that the smallest

available size of intended equipment might not meet the proposed sizing

requirement. The Department would appreciate comments on what designers

should do if unable to obtain equipment within the equipment capacity

requirements.

g. Section 435.503.5.7.2: Duct sealing. The proposed rule would

contain duct sealing requirements that are more stringent than those in

the MEC, 1992. A requirement that all low-pressure air ducts be sealed

with mastic with fibrous backing tape was added as section

435.503.5.7.2 of the proposed rule. This requirement is also in the

MEC, 1995.

Leaking supply and return ducts decrease heating and cooling

equipment efficiency and increase energy usage while not meeting

resident comfort requirements. Many studies of actual houses have

revealed leaky ducts to be a major source of energy loss. One study

showed leaks of 15 percent can reduce air conditioner efficiency by

33--50 percent. See the Technical Support Document, section 6.4, page

6.4. To address these problems, the proposed rule requires all low-

pressure supply and return ducts outside the conditioned space to be

sealed with mastic with fibrous backing tape. In contrast, the MEC,

1992 requires only that the supply ducts are sealed and allows any type

of tape.

Current construction practice allows the use of duct tape to

``seal'' cracks and crevices in supply and return air ducts. Duct tape

however, is not a sealant. A clean surface and a tight fit are required

to produce a ``seal'' at installation and neither of these conditions

is routinely met. If a ``seal'' is obtained at installation, however,

the tape degrades over time as a result of deterioration of the glue.

Properly installed duct tape ``seals'' often will leak within a year or

two. Repairing leaking ducts after construction can be costly or

impractical because ducts are often in inaccessible locations or they

are wrapped with insulation that must be removed and replaced.

Mastic is a permanent sealant. It does not degrade over time, and

is expected to last for the life of the home. Installation is

uncomplicated, with several methods of application from which to

choose. Mastic has excellent adhesive and cohesive properties, even on

typically dirty or oily surfaces found at the construction site. The

cost of sealing ducts in existing housing is estimated to range from

$50 to $300 when the installer has unrestricted access to the ducts

without making it necessary to remove the finished material that may

cover the ducts. The cost will clearly be lower during construction in

new housing. This requirement is technologically feasible because

mastic and tape sealing are found in current building construction

practice. The requirement is economically justified because the cost of

the energy saved over the 25-year analysis period would exceed the cost

of the additional labor and materials that would be used to comply with

this section. See the Technical Support Document, section 6.4, page

6.4.

h. Section 435.503.5.9.1: Backdrafting test. The Department has

included requirements relating to the prevention of backdrafting of

fossil-fuel-burning appliances in the proposed rule. The MEC, 1992 has

no requirements relating to this potential health hazard. Chimney

backdrafting in fossil-fuel-burning appliances such as oil or gas-fired

water heaters, gas-fired clothes driers, fireplaces, or wood stoves is

a potential threat to occupant health in residential buildings. Chimney

backdrafting can occur when exhaust gases are drawn into a building

through the chimney or vent because air pressure is lower inside the

building than outside. Chimney backdrafting can cause serious health

problems and even death can occur from exhaust gases containing or

leading to the formation of carbon monoxide. Infants are particularly

at risk because their respiratory systems are not fully developed, and

they are susceptible to health effects at lower concentrations than are

safe for most healthy adults. Sulfur dioxide and carbon dioxide also

circulates in occupant breathing spaces as a result of backdrafting.

These gases can cause long-term health effects such as chronic

respiratory illness, or short-term health effects such as discomfort,

shortness of breath, and respiratory irritation.

The Department has determined that tests for potential backdraft

problems should be performed in all homes with fossil-fuel-burning

appliances that do not obtain exhaust combustion air directly from the

outside. These tests shall be performed because the potential for

chimney or venting failure exists in all homes and especially in all

well sealed, poorly ventilated homes with combustion equipment. Tight

building envelopes can cause stack-effect-induced depressurization and

powered exhaust fans can exacerbate the problem.

The test specified in the proposed rule is taken from the Canadian

spillage test developed by the Canadian General Standards Board. The

test measures the inside/outside pressure differential across a

building shell with a micromanometer under best-case and worst-case

scenarios. The test then compares the measurements to depressurization

limits for combustion appliances in the house. When depressurization

measurements exceed limits, remedial action is required before the

house can pass the spillage test and comply with the rule. The

Department has reviewed the Canadian spillage test and determined that

it is technologically feasible and has included it in the proposed

rule. See Technical Support Document, section 8.0, page 8.1.

The cost to perform a backdrafting test is estimated to be between

$50 and $100, depending on factors such as: the complexity of the

house, the number of houses in a given area to be tested, and local

weather conditions. This cost range does not include remedial measures.

The Department has determined that there is a potential risk of

backdrafting which justifies the inclusion of this requirement which is

consistent with health and safety needs. See the Technical Support

Document, section 8.0 for more information. The Department requests the

public to comment on whether carbon monoxide alarms should be required

in Federal residences.

i. Section 435.504.2: Service water heating equipment. Section

435.504.2 addresses the selection of service water heating equipment

with the application of life-cycle cost requirements. As with space

heating and cooling equipment, Federal agencies may either (1) select

the most cost-effective domestic water heating equipment that minimally

complies with Federal standards or (2) select any other equipment that

is at least as life-cycle cost-effective. More efficient equipment may

be selected under Subpart E. Agencies are encouraged through the

Procurement Challenge program and other Federal initiatives to consider

more energy-efficient equipment.

j. Section 435.504.4: Heat traps. Heat traps are one-way valves or

pipe configurations that prevent thermal diffusion or thermal siphoning

of

[[Page 24172]]

potable water from the hot water heater in the house through the water

distribution system, thus needlessly dissipating heat. Section

435.504.4 of the proposed rule requires that water heaters with

vertical pipe risers have heat traps. This requirement is not in the

MEC, 1992 and was taken from the codified version of Standard 90.2-

1993. Heat traps are also technologically feasible because they are

part of current water heater manufacturing practice. The use of heat

traps is a low-cost method of reducing water heating energy use already

installed on many commercially available water heaters. Therefore, heat

traps are economically justified because the net annual savings over

the lifetime of the water heater exceeds the initial first cost of the

additional hardware. See the Technical Support Document, section 6.5,

page 6.5.

2. Miscellaneous Revisions That Are Contained in Subpart E of the

Proposed Rule, Not in the MEC, 1992

The proposed rule includes the following additional requirements

that are not part of the MEC, 1992. Section 435.502.1.4 contains a

clarification to the MEC, 1992 in that access openings, which are

considered part of the thermal envelope element, must be evaluated as

part of the overall building thermal envelope element (e.g., floors,

walls, roof/ceiling, etc.,). The Department believes this is

technologically feasible because access openings are commonly insulated

in colder climates and are economically justified because it imposes no

additional cost to the building. See the Technical Support Document,

section 6.9, page 6.10.

Section 435.502.1.5 contains a requirement for the insulation of

foundations supporting masonry veneer. The Department has determined

that the requirement is technologically feasible because it reflects

current building construction practice. Although some energy would be

lost, the energy loss would be small and economically justified when

weighed against the costs that would be incurred by damage to the

masonry veneer. Damage can occur due to settling of the masonry as the

insulation is compressed. The technical justification for this

requirement may be found in the Technical Support Document, section

6.10, page 6.10.

Section 435.502.2.1.3 contains an equation to calculate the total

floor heat loss of the proposed building. The equation requires that

all floors of different construction (in aggregate) must meet the

U0 requirements for floors over unheated spaces. The

Department has determined that the requirement is technologically

feasible. The technical justification for this requirement may be found

in the Technical Support Document, section 6.11, page 6.10. The

equation is economically justified because the use of the equation to

determine the U-value requirement for floors over unheated spaces is

cost-effective. Variations in floor configurations are not required by

this proposed rule.

Section 435.502.2.1.4 contains a clarification of acceptable slab

insulation placement which reflects current building construction

practice. The Department has determined that the requirement is

technologically feasible because it reflects current standard building

construction practice. The technical justification for this requirement

may be found in the Technical Support Document, section 6.11, page

6.11. The clarification is economically justified because it imposes no

additional slab insulation requirements. There is a potential for

installation cost savings due to the flexibility offered by the

proposed requirement.

Section 435.502.3.2 simplifies language on caulking and sealing

requirements for typical air sealing measures. The Department has

determined that the requirement is technologically feasible because the

simplified language generally reflects the requirements contained in

the MEC, 1992. The technical justification for this requirement may be

found in the Technical Support Document, section 6.13, page 6.12. The

simplified language is economically justified because it imposes no

additional costs to the construction of the building.

Section 435.502.3.1 refers to updated reference standards for

allowable infiltration rates for windows and doors. This section

reflects current manufacturing standards for air-tightness of pre-

fabricated windows and doors. The Department has determined that the

requirement is technologically feasible because current manufactured

windows and doors are built to the updated referenced standards. The

updated reference standards are economically justified because the

proposed rule imposes no additional cost or requirements on

manufacturing quality or performance. The technical justification for

this requirement may be found in the Technical Support Document,

section 6.15, page 6.14.

F. Subpart F: [ Reserved ]

Subpart F is reserved for a simplified compliance approach the

Department is developing. This approach will make it easier to

determine compliance with this rule. This revised simplified compliance

approach would be different from that contained in the MEC, 1992, 1993,

and 1995. This approach is expected to be similar to the Department's

``MECcheck'' tables which display pre-calculated configurations in

compliance with the MEC, 1992, 1993 or 1995. The Department is planning

to produce a ``Federal'' version of MECcheck.

G. Subpart G: Radon Control

Subpart G provides the minimum requirements for the control of

radon from the ground and from construction materials associated with

Federal residential buildings. The application of requirements for

radon control apply in addition to the provisions of Subpart D or E.

The ECPA, as amended, directs that the Federal residential building

energy standard ``consider, in consultation with the Environmental

Protection Agency and other Federal agencies, and where appropriate

contain, measures with regard to radon and other indoor air

pollutants.'' 42 U.S.C. 6834(a)(2)(C). The intent is for the Department

to address health concerns related to air quality in Federal buildings.

The Department has determined that radon is a potential health

hazard in residential buildings and that the proposed rule should

address radon testing and mitigation requirements. Radon is a gas that

exists naturally in many soils and enters a building through the

foundation. Radon concentrations in soil vary widely across the United

States and even within a small region, such as a county. If high

concentrations of radon are present in the soil below a building, then

measures to control radon are needed. Approximately 6 percent of

existing single-family homes in the United States or 5.8 million homes

in 1990 have average radon levels greater than 4 pCi/L per year, the

threshold level determined by the EPA to require corrective action.

Approximately 0.7 percent of existing single-family homes in the

country have average radon levels greater than 10 pCi/L per year. The

EPA estimates that indoor radon causes between 7,000 and 30,000 lung

cancer deaths per year. This range is based on the uncertainty inherent

in the many factors contributing to the risk of radon exposure and on a

national residential radon survey estimate of an average level of 1.25

pCi/L per year. The EPA's best estimate is that 14,000 lung cancer

deaths per year result from residential radon exposure.

[[Page 24173]]

In this proposed rule the Department would be accepting EPA's

determination that radon-resistance control measures should only be

required in zones (counties) of high radon potential. Such zones are

defined by the EPA ``U.S. Map of Radon Zones'' or local data if

available. The proposed rule specifies the EPA ``U.S. Map of Radon

Zones'' as the default source designating counties where the proposed

requirements apply. Table 702.2 in the Appendix of the proposed rule

lists the applicable counties. The EPA ``U.S. Map of Radon Zones'' is

not always sufficient to predict radon concentrations accurately. There

may be instances where specific locations will be assigned to an

inappropriate radon potential zone in the EPA ``U.S. Map of Radon

Zones''. To accommodate for such inaccuracies, the proposed rule allows

considering appropriate evidence and ``overruling'' the EPA ``U.S. Map

of Radon Zones.''

Consideration of non-EPA data is justifiable given that studies on

radon concentrations in many Federal installations are already

available or are underway.

The proposed rule uses the following approach for addressing radon

when radon-resistant construction is necessary:

(1) Foundation sealing with passive (non-mechanical) venting of

soil gas to the outside;

(2) Long-term and short-term post-occupancy radon testing to verify

occupant safety;

(3) Mitigation, if the tests reveal high radon concentrations; and

(4) Post-mitigation testing for radon and potential backdrafting to

ensure safety.

Each of these four approaches is described in further detail below.

The proposed radon requirements are technologically feasible because

the techniques used are part of current standard building construction

practice in many areas of the U.S. and are consistent with the EPA

Model Standards and Techniques for Control of Radon in New Residential

Buildings (EPA 402-R-94-009, March 1994). The Department is accepting

EPA's analysis of the costs and benefits of radon control. See RS-34,

pages ES-1-ES-4. The Technical Support Document (Chapter 7.0) provides

construction specifications and technical justifications for the

proposed rule. The proper initial abatement approach in areas of

potentially high radon concentrations is to seal potential sources of

air leakage in the foundation and vent the soil gas below the

foundation. Such venting uses a pipe that extends from the foundation,

through the house, and out the roof. This approach is consistent with

the approach in the EPA Radon Mitigation Standards (EPA 402-R-93-078,

October 1993). It cannot be conclusively determined before construction

that a radon source exists that is strong enough to raise indoor

concentrations above the EPA action level. Therefore, it would be

fiscally imprudent initially to require measures beyond foundation

sealing and the ``passive'' vent pipe. If elevated radon levels are

found after construction and these initial measures were not installed,

the cost of the retrofit would be much higher than the cost during

initial construction.

The radon concentration within a residence can only be determined

after the residence is built and occupied. This is due to the

interaction of radon sources with construction characteristics of the

house and the indoor pressure-driven air flow that is influenced by

heating, ventilating and air-conditioning equipment under occupant

control. Because short-term tests are not adequate to obtain annual

average radon concentrations, the proposed rule requires long-term

post-occupancy testing of residences built in specified locations. The

long-term test requires between 6 months and 1 year and is the most

accurate measure of chronic radon levels an occupant will encounter. A

short-term test which lasts between seven and 60 days, is also proposed

to ensure that occupants are not exposed to radon levels in excess of

20 pCi/L while the long-term test is in progress. Testing procedures

and devices must conform to the EPA Protocols for Radon and Radon Decay

Measurements in Homes (EPA 402-R-93-003, June 1993).

Testing may show that sealing the foundation and installing the

passive vent are not sufficient to control the radon level. In such

cases, the proposed rule requires that a fan be installed and operated

in the foundation vent system to lower radon concentrations. Vent fans

must be activated when the long-term test reveals radon concentrations

greater than the EPA action level of 4 pCi/L or if the first short-term

test and a second short-term confirmatory test reveals radon levels in

excess of 20 pCi/L. The EPA Radon Mitigation Standards offer guidance

on installing the fan.

Follow-up tests are required to ensure that the vent fan is

successful at lowering indoor radon levels. Additionally, because the

foundation vent fan may under certain circumstances cause fossil-fuel-

burning appliances to tend to backdraft, both the proposed rule and the

EPA Radon Mitigation Standards require testing for backdrafting of

chimney and combustion vents. Section 435.503.5.9.1 of the proposed

rule, referenced in Subpart G, specifies the test procedure to be used

to check for potential backdrafting.

The Department departs from the EPA ``Radon Mitigation Standards''

in several respects. First, the proposed rule allows data on radon

concentrations at Federal facilities to take precedence over the EPA

``U.S. Map of Radon Zones'' for determining whether radon-resistant

construction is required. Second, if the housing is located in a high

radon zone, the proposed rule requires testing and, if necessary,

mitigation and further post mitigation testing. Third, many sections of

the EPA Radon Mitigation Standards that are unenforceable, including

discussions, explanations, or recommendations, have been deleted.

Fourth, the Department provides more detail in some construction

specifications so that the required measures can be more easily

verified. Fifth, the Department did not explicitly include the EPA

requirements for sealing the above-grade structure to help limit air

infiltration through the foundation. This was because similar

requirements are already included in section 435.502.3 of the proposed

rule.

The Department has thus followed the general approach outlined in

the EPA Radon Mitigation Standards. Radon-resistant construction is

only required in locations with high radon potential and a phased

approach to control is specified. Control should be based on a sealed

foundation, passive venting of soil gas and radon testing after

occupancy. Only if necessary should a fan be added to the vent system.

The Department consulted and provided to the EPA draft copies of the

proposed rule (including radon requirements) and the Environmental

Assessment supporting the proposed rule. The EPA has provided extensive

comments on the requirements for radon in the proposed rule and the

Department has incorporated many of those comments in Subpart G.

H. Subpart H: Standards

This section provides a list of all the standards referenced in the

proposed rule. This section has been updated from the MEC, 1992 because

some requirements contained in this proposed rule are not contained in

the MEC, 1992 reference standards. Also, some referenced standards have

been updated to newer versions since 1992.

[[Page 24174]]

IV. Consultation

In developing today's proposal, the Department has consulted with

outside parties, including state and local code officials, private

sector representatives, and other Federal agencies, as required by

section 305(a)(1) of ECPA.

In addition, the Department continues to work with the relevant

private sector organizations and the states to analyze potential

improvements to the MEC and to facilitate the adoption of such

improvements in both the public and private sectors. Adoption of the

MEC format in today's proposal provides a ready basis for the

incorporation of future code improvements as they are developed and

approved through the standard process for model code change proposals.

Finally, the Department will specifically provide Federal agencies

with information regarding the availability of energy-efficiency

equipment and emerging developments that improve building envelopes.

This support will help keep Federal agencies current regarding energy-

efficiency opportunities between the updates of this rule.

V. Energy and Economic Impacts

Section 305(a)(2)(A) of ECPA requires that the proposed rule meet

or exceed the MEC, 1992. The proposed rule is based on the MEC, 1992,

with the additions described in Section III above. Overall, the

proposed rule, if adopted would reduce energy use by approximately 11

percent for single-family residences and 26 percent for multi-family

residences, as compared to the MEC, 1992.

The energy estimates reported here are based on the minimum

specifications required in Subpart E of the proposed rule. Additional

cost-effective energy-efficiency improvements in new Federal

residential buildings are facilitated by this rule through Subpart D,

which provides a means of documenting the energy savings and cost-

effectiveness of more energy-efficient building designs.

The Department has prepared a Technical Support Document that

includes an economic analysis. It concludes that there are no

significant adverse economic effects from adopting the proposed rule.

The proposed rule, when compared to the MEC, 1992, will result in a

positive net flow of benefits from energy savings that more than

offsets higher capital construction and other costs at estimated

Federal costs of energy.

The national net effect of the proposed rule is a cumulative

savings of $870,000 for the approximately 3,000 Federal housing units

constructed each year. These net effects are based on the net present

value of energy savings and capital costs over a 25-year period. See

the Economic Analysis at page 6.

VI. Technological Feasibility and Economic Justification

The standards proposed today are technologically feasible and

economically justified to the Federal government as required by Section

305(a)(1) of ECPA.

The Department used the life-cycle cost methodology reflected in

the microcomputer program entitled ``ARES'' for evaluating the life-

cycle cost-effectiveness of various thermal envelope EEMs. Only those

EEMs the Department judged technologically feasible were reviewed.

The life-cycle cost analysis compares the cost and benefits of all

the EEMs. The HVAC equipment performance efficiencies are specified at

current minimum EPCA levels. See 10 CFR Part 430. These are the same

levels found in the MEC, 1993. Given a set of fuel prices, financial

and economic parameters, and EEM costs for a specific location, ARES

identifies the life-cycle cost resulting from any given set of EEMs.

Energy costs and discount rates reflect estimated Federal costs of

energy and the Federal discount rate established annually by the

Federal Energy Management Program for the life-cycle cost analysis

required by 10 CFR Part 436. The present value of the total costs for

several EEMs are compared, and the results are used to set the code to

energy-efficiency measure levels that achieve the lowest energy-related

total cost for construction, operation and maintenance for each

location studied. The resulting thermal-envelope-component values are

presented as a function of heating degree-days.

The technical feasibility of the EEMs contained in the ARES energy

data base was assessed by determining that they were technologically

verifiable, commercially available, and in common construction

practice. Construction features that cannot be analyzed by ARES because

the technical or economic data has not been well established, or

features that have small additional costs but significant potential for

energy savings, have been analyzed by practicable architectural,

engineering, or economic judgment.

VII. Measures Concerning Radon and Other Indoor Air Pollutants

Section 305(a)(2)(C) of the ECPA requires the Department to

consider, where appropriate, measures with regard to radon and other

indoor air pollutants. The Department has proposed a set of radon

requirements concerning the control and mitigation of radon in Federal

residences. These requirements draw heavily from the EPA Radon

Mitigation Standards, EPA 402-R-93-078, April 1994. As part of these

proposed requirements, post-occupancy testing is proposed for locations

with high radon potential to discover whether radon concentrations

within the residences are acceptable. The proposed Federal rule also

includes requirements for addressing the potential for backdrafting of

combustion by-products, such as carbon monoxide, from fossil-fuel-

burning appliances.

VIII. Findings and Certification

A. Review Under the National Environmental Policy Act

The Department has completed an Environmental Assessment (EA), see

Environmental Assessment of the Impacts on Building Habitability and

the Outdoor Environment Resulting from the Proposed Federal Residential

Code, in support of the proposed rule, pursuant to the implementing

regulations of the Council on Environmental Quality (CEQ) (40 CFR Parts

1500-1508), the ``National Environmental Policy Act of 1969, as

amended,'' (NEPA) (40 U.S.C. 4221 et seq.), the Department's NEPA

Implementing Procedures, (10 CFR Part 1021), and the Secretarial Policy

on the National Environmental Policy Act (June 1994). Section V.B.2. of

the Secretarial Policy requires, wherever possible, that the Department

provide an opportunity for interested parties to review environmental

assessments prior to the Department's formal approval of such

assessments. The written public comment procedures for this EA are

discussed below in section IX.

The draft EA addresses the possible incremental environmental and

indoor habitability effects attributable to the application of the

proposed rule. The analysis in the draft EA demonstrates that the

potential environmental effects from the proposed rule would be

limited. The only impacts would be a decrease in outdoor air pollutants

resulting from decreased fossil fuel burning and temporary increases in

formaldehyde concentrations in the Federal residences.

B. Environmental Protection Agency Review

As required by the Federal Energy Administration Act of 1974, 15

U.S.C. 766(a)(1), a copy of this proposed rule

[[Page 24175]]

was submitted to the Administrator of the Environmental Protection

Agency for comments on the impact of the proposed rule on the quality

of the environment.

C. Regulatory Planning and Review

This regulatory action has been determined to be a significant

regulatory action under Executive Order No. 12866, 58 FR 51735 (October

4, 1993), but not economically significant. Accordingly, today's action

was subject to review under the Executive Order by the Office of

Information and Regulatory Affairs (OIRA) and OIRA has completed its

review.

D. Federalism Review

Executive Order 12612, 52 FR 41685 (October 30, 1987), requires

that regulations, rules, legislation, and any other policy actions be

reviewed for any substantial direct effects on states, on the

relationship between the Federal government and the states, or in the

distribution of power and responsibilities among various levels of

government. If there are substantial effects, then the Executive Order

requires preparation of a federalism assessment to be used in all

decisions involved in promulgating and implementing a policy action.

The proposed rule would establish energy-efficiency requirements

solely applicable to new Federal residential buildings. It does not

impose any requirements on state governments. Therefore, the Department

finds that today's proposed rule, if finalized, will not have a

substantial direct effect on state governments, therefore, a federalism

assessment has not been prepared.

E. Review Under the Executive Order on Metric Usage in Federal

Government Programs

Section 5164(b) of the Omnibus Trade and Competitiveness Act of

1988, 15 U.S.C. 205b, which amended the Metric Conversion Act of 1975,

designates the metric system of measurement as the preferred system of

weights and measures for trade and commerce. This law requires Federal

agencies by the end of fiscal year 1992 and to the extent economically

feasible, to use the metric system in U. S. procurements, grants, and

other business-related activities, except to the extent that such use

is impractical or likely to cause significant inefficiences or loss of

markets to U.S. firms. The Omnibus Trade and Competitiveness Act of

1988 also requires Federal agencies to establish guidelines and to

report as part of its annual budget submission on the actions it plans

in order to implement fully the metric system of measurement. This

policy is also stated and amplified by Executive Order 12770 of July

25, 1991, ``Metric Usage in Federal Government Programs.''

This rule is the first use of a dual metric/English (soft metric

conversion) system of measurement in a Federal building energy

regulation. The metric system of measurement is followed by the English

system in parentheses. In using this dual system, the Department is

facilitating the goal of 15 U.S.C. 205b to promote competitiveness by

relating Federal energy standards to the international measurements

that United States companies must use to meet world demand for building

components. The rule retains reference to English system measurements

for those companies that do not have the ability to readily translate

between metric and English units. The use of this dual system of

measurement does not change the requirements of the proposed rule and

has no substantive impact on the users of the proposed rule.

F. Review Under Executive Order on Civil Justice Reform

Section 3 of Executive Order 12988, 61 FR 4729 (February 7, 1996),

instructs each agency to adhere to certain requirements in promulgating

new regulations. These requirements, set forth in Section 3(a) and (b),

include eliminating drafting errors and needless ambiguity, drafting

the regulations to minimize litigation, providing clear and certain

legal standards for affected legal conduct, and promoting

simplification and burden reduction. Agencies are also instructed to

make every reasonable effort to ensure that the regulation describes

any administrative proceeding to be available prior to the judicial

review and any provisions for the exhaustion of administrative

remedies. The Department has determined that today's regulatory action

meets the requirements of section 3(a) and (b) of Executive Order

12988.

G. Review Under the Regulatory Flexibility Act

The Regulatory Flexibility Act of 1980, 5 U.S.C. 601-612, requires

that an agency prepare an initial regulatory flexibility analysis and

that it be published at the time of publication of general notice of

proposed rulemaking for the rule. This requirement does not apply if

the agency ``certifies that the rule will not, if promulgated, have a

significant economic impact on a substantial number of small

entities.'' 5 U.S.C. 605.

The proposed rule only imposes requirements on the Federal

government for the construction of new Federal residential buildings.

Therefore, the Department certifies that this rule, if promulgated,

would not have a significant economic impact on a substantial number of

small entities.

H. Paperwork Reduction Act Review

This proposed rule was examined with respect to the Paperwork

Reduction Act, 44 U.S.C. 3501 et seq., which directs agencies to

minimize Federal information collection and reporting burdens imposed

on individuals, small businesses, and state and local governments.

This proposed rule would establish requirements for the design of

new Federal residential buildings. It does not impose requirements for

the collection or reporting of information to the Federal Government.

Accordingly, clearance under the Paperwork Reduction Act of 1980 is not

required by the Office of Information and Regulatory Affairs of the

Office of Management and Budget.

I. Review Under Section 32 of the Federal Energy Administration

Authorization Act

Pursuant to Section 301 of the Department of Energy Organization

Act (Pub. L. 95-91), the Department is required to comply with Section

32 of the Federal Energy Administration Authorization Act of 1974, as

amended by section 9 of the Federal Energy Administration Authorization

Act of 1977. The findings required of the Department by Section 32

serve to notify the public regarding the use of commercial standards in

a proposal and through the rulemaking process. It allows interested

persons to make known their views regarding the appropriateness of the

use of any particular commercial standard in a notice of proposed

rulemaking. Section 32 also requires that the Department consult with

the Attorney General and the Chairman of the Federal Trade Commission

concerning the impacts of such standards on competition.

Today's proposed rule adopts, in significant part, the MEC, 1992,

1993 and 1995 and the relevant reference standards (RS) contained in

the MEC, 1992, 1993, and 1995. The reference standards can be found in

Subpart H of the proposed rule designated as RS-1--RS-34. In addition,

the proposed rule adopts certain requirements from Standard 90.2-1993.

The Department has evaluated the promulgation of the above

standards with regard to compliance with Section

[[Page 24176]]

32(b). The Department is unable to conclude whether these standards

fully comply with the requirements of Section 32(b), i.e., that they

were developed in a manner which fully provided for public

participation, comment, and review. Therefore, the Department now

invites public comment on the appropriateness of incorporating these

industry standards in its final rule. As required by Section 32(c), the

Department will consult with the Attorney General and the Chairman of

the Federal Trade Commission concerning the impact of these standards

on competition, prior to issuing a notice of Final rulemaking.

J. Unfunded Mandates Reform Act Review

Title II of the Unfunded Mandates Reform Act of 1995 (the Act),

enacted as Pub. L. 104-4 on March 22, 1995, requires each Federal

agency, to the extent permitted by law, to prepare a written assessment

of the effects of any Federal mandate in a proposed or final agency

rule that may result in the expenditure by state, local, and tribal

governments, in the aggregate, or by the private sector, of $100

million or more (adjusted annually for inflation) in any one year. The

requirements do not apply if the rule incorporates regulatory

requirements that are specifically set forth in law. 2 U.S.C. 1531,

1532.

Furthermore, section 204(a) of the Act, 2 U.S.C. 1534(a), requires

the Federal agency to develop an effective process to permit timely

input by elected officers (or their designees) of state, local, and

tribal governments on a proposed ``significant intergovernmental

mandate.'' A ``significant intergovernmental mandate'' under the Act is

any provision in a Federal agency regulation that: (1) would impose an

enforceable duty upon state, local, or tribal governments (except as a

condition of Federal assistance); and (2) may result in the expenditure

by state, local, and tribal governments, in the aggregate, of $100

million (adjusted annually for inflation) in any one year. Section 203

of the Act, which supplements section 204(a), provides that before

establishing any regulatory requirements that might significantly or

uniquely affect small governments, the agency shall have developed a

plan that, among other things, provides for notice to potentially

affected small governments, if any, and for a meaningful and timely

opportunity to provide input in the development of regulatory

proposals. 2 U.S.C. 1533.

The rule proposed today would establish building energy-efficiency

standards for new Federal residential buildings pursuant to section

305(a) of the Energy Conservation and Production Act, as amended. 42

U.S.C. 6834(a). It does not include any Federal requirements that would

result in the expenditure of money by state, local, and tribal

governments. Therefore, the requirements of the Unfunded Mandates

Reform Act of 1995 do not apply to this rulemaking.

IX. Public Comment Procedures

A. Participation in Rulemaking

The Department encourages the maximum level of public participation

in this rulemaking. Representatives of Federal agencies, utilities,

state and local governments, building code organizations, and builder

associations, building owner associations, as well as individuals,

architects, engineers, builders, building owners, consumers, and others

are urged to submit written statements on the proposed rule. The

Department also encourages interested persons to participate in the

public hearing to be held in Washington, D.C., at the time and place

indicated in this Notice.

The Department of Energy has established a comment period of 90

days following publication for interested persons to comment on this

proposed rule. All comments will be available for review in the

Department's Freedom of Information Reading Room.

B. Solicitation of Public Comments

The Department welcomes comments on any aspects of the proposed

rule and supporting documentation, including the draft EA. In

particular, the Department is seeking comments on those specific issues

described below. The Department requests that comments of a technical

nature be supported by substantive data.

In particular, the Department requests comments addressing the

quantitative and methodological basis for setting specific ventilation

requirements in energy codes that relate to Federal residential

construction. Ventilation can help mitigate indoor air pollutants and

moisture problems in many situations. Excessive ventilation, however,

can increase energy use but not necessarily mitigate the health effects

of some indoor air pollutants. The Department is interested in comments

on how best to set ventilation requirements to achieve adequate indoor

air quality without incurring unnecessary construction or energy costs.

Second, the Department seeks comments on whether all residences

with fuel-burning devices requiring a vent pipe or chimney should be

required to undergo testing for depressurization-induced chimney

failure (backdrafting). The Department has included this requirement in

the proposed rule because of the health hazard of backdrafting.

Third, the Department specifically requests comments regarding the

treatment of equipment efficiency for space heating and cooling and

water heating. The proposed rule incorporates the existing Federal

minimum appliance standards, while relying on other Federal initiatives

to encourage the identification and use of more efficient equipment

where economically justified.

The Department would have to establish the economic benefits and

technological feasibility of any equipment efficiency specifications

that would be included in this rule that exceed the Federal minimum

requirements.

Fourth, the Department requests comments concerning the

technological feasibility and economic justification relative to the

heating and cooling equipment sizing provisions contained in the

proposed rule.

Fifth, the Department requests comments concerning suggestions on

approaches for crediting measures that use renewable sources of energy.

Sixth, the Department requests comments on the appropriateness of

the approach identified in section 435.402.1.6 of the proposed rule for

dealing with equipment efficiencies under the whole building energy

analysis compliance path in Subpart D.

Seventh, the Department requests comments on whether carbon dioxide

alarms should be required in Federal residences.

Eighth, the Department requests comment on how this proposed rule

could address equipment technologies for which a means of evaluating

and comparing energy performance has not yet been fully developed.

Finally, as previously stated, the Department of Energy requests

public review and comments on the draft EA.

C. Written Comment Procedures

Interested persons are invited to participate in this proceeding by

submitting written data, views, or comments with respect to the

proposed rulemaking.

Written comments (ten copies) shall be submitted to the address

indicated in the ADDRESSES section of this notice. The copies must be

received by the date indicated in the DATES section of this notice.

Comments should be identified on both the outside of the envelope and

on the documents themselves with the

[[Page 24177]]

designation, Energy Efficiency Code for New Federal Residential

Buildings (Docket No. EE-RM-96-300). In the event any person wishing to

provide written comments cannot provide ten copies, alternative

arrangements can be made in advance with the Department.

All comments received on or before the date specified at the

beginning of this proposed rule and other relevant information will be

considered by the Department before final action is taken on the

proposed rule. All written comments will be available for examination

in the Rule Docket File in the Department's Freedom of Information

Office Reading Room at the address provided at the beginning of this

document before and after the closing date for comments. In addition, a

transcript of the proceedings of the public hearings will be filed in

the docket.

Pursuant to the provisions of 10 CFR 1004.11, any person submitting

information that is believed to be confidential, and which may be

exempt by law from public disclosure, should submit one complete copy,

and two copies from which the information believed to be confidential

has been deleted. The Department will make its own determination of any

such claim and treat it according to its determination.

D. Public Hearings

1. Procedure for Submitting Requests To Speak

To have the benefit of a broad range of public viewpoints in this

rulemaking, the Department will hold a public hearing at the time and

place indicated in the DATES and ADDRESSES sections of this notice. Any

person who has an interest or who is a representative of a group or

class of persons that has an interest in the proposed rule or the

associated environmental assessment may request an opportunity to make

an oral presentation. A request to speak at the public hearing must be

mailed to the address or telephoned to the number indicated in the

ADDRESSES section of this notice and received by the time specified in

the DATES section of this notice.

The person making the request should briefly describe his or her

interest in the proceedings and, if appropriate, state why that person

is a proper representative of the group or class of persons that has

such an interest. The person should also provide a telephone number

where he or she may be contacted during the day. Each person selected

to be heard will be notified by the Department as to the approximate

time he or she will be speaking. Ten copies of the speaker's statement

must be submitted at or before the hearing. In the event any person

wishing to testify cannot meet this requirement, alternative

arrangements can be made in advance with the Department.

2. Conduct of Hearings

The Department reserves the right to schedule persons to be heard

at the hearing, to schedule their representative presentations, and to

establish procedures governing the conduct of the hearing. The length

of each presentation is limited to 15 minutes or otherwise based on the

number of persons requesting an opportunity to speak.

A Department official will preside at the hearing. This will not be

a judicial or evidentiary-type hearing. It will be conducted in

accordance with 5 U.S.C. 553 and Section 501 of the Department of

Energy Organization Act, 42 U.S.C. 7191. At the conclusion of all

initial oral statements, each person who has made an oral statement

will be given the opportunity to make a rebuttal or clarifying

statement. The statements will be given in the order in which the

initial statements were made and will be subject to time limitations.

Questions may be asked only by those conducting the hearing. Any

interested person may submit to the presiding official written

questions to be asked of any person making a statement at the hearing.

The presiding official will determine whether the question is relevant

or whether time limitations permit it to be presented for a response.

Any further procedural rules needed for the proper conduct of the

hearing will be announced by the presiding official at the hearing.

A transcript of the hearing will be prepared by the Department and

made available as part of the administrative record for this

rulemaking. It will be on file for inspection at the Department's

Freedom of Information Reading Room as provided at the address

indicated at the beginning of this document.

If the Department must cancel the public hearing, the Department

will make every effort to publish an advance notice of such

cancellation in the Federal Register. The hearing date may be canceled,

for example, in the event no member of the public requests the

opportunity to make an oral presentation.

List of Subjects in 10 CFR Part 435

Buildings, Energy conservation, Energy efficiency, Engineers,

Federal buildings and facilities, Housing.

Issued in Washington, DC, on April 1, 1997.

Brian T. Castelli,

Chief of Staff, Energy Efficiency and Renewable Energy.

For the reasons set forth in the preamble, Part 435 of Chapter II

of Title 10 of the Code of Federal Regulations is proposed to be

revised as set forth below:

PART 435--ENERGY EFFICIENCY CODE FOR NEW FEDERAL RESIDENTIAL

BUILDINGS

435.100 Explanation of numbering system for this part.

Subpart A--Administration and Enforcement

435.101 Scope and general requirements.

435.102 Materials and equipment.

435.103 Alternate materials'method of construction, design, or

insulation systems.

435.104 [Reserved].

435.105 [Reserved].

435.106 [Reserved].

435.107 Precedence.

435.108 Life-cycle cost analysis.

Subpart B--Definitions

435.201 Definitions.

Subpart C--Design Conditions

435.301 Scope.

435.302 Thermal design parameters.

435.303 Mechanical ventilation criteria.

Subpart D--Design by Systems Analysis; Design Utilizing Renewable

Energy Sources

435.401 Scope.

435.402 Systems analysis.

435.403 Renewable energy source analysis.

Subpart E--Design by Component Performance Approach

435.501 Scope.

435.502 Building thermal envelope requirements.

435.503 Building mechanical systems and equipment.

435.504 Service water heating.

435.505 Electrical power and lighting.

Subpart F--[Reserved]

Subpart G--Radon Control

435.701 General.

435.702 Scope.

435.703 Compliance.

435.704 Alternative systems.

435.705 Conflict with other standards, codes, or regulations.

435.706 Qualification of testers and installers.

435.707 Design and construction requirements.

Subpart H--Standards

435.801 Reference standards.

435.802 Abbreviations and acronyms used in reference standards.

[[Page 24178]]

Appendix to Part 435 Figures and Tables

Authority: 42 U.S.C. 6831-6832, 6834-6836; 42 U.S.C. 8253-54; 42

U.S.C. 7101, et seq.

Sec. 435.100 Explanation of numbering system for this part.

100.1 General. For the purposes of this part, a derivative of two

different numbering systems will be used.

100.1.1 For the purpose of designating a section, the numbering

system employed in the Code of Federal Regulations (CFR) will be

employed. The number ``435'' which signifies part 435, Chapter II of

Title 10, Code of Federal Regulations, is used as a prefix for all

section headings. The suffix is a three digit number. For example, the

life-cycle cost analysis section of this part is designated

Sec. 435.108.

100.1.2 Within each section, a numbering system common to many

national voluntary consensus model codes is used. A decimal system is

used to denote paragraphs and subparagraphs within a section. For

example, 435.502.1.2 refers to subparagraph 2 of paragraph 1 of

Sec. 435.502.

100.2 The hybrid numbering system is used for two purposes:

100.2.1 The use of the Code of Federal Regulation numbering system

allows the researcher using the CFR easy access to this part.

100.2.2 The use of the second system allows the builder, designer,

architect or engineer easy access to the technical provisions because

they are familiar with the numbering system and its format generally

conforms to existing building codes. This system was chosen because of

its commonality among the buildings industry.

Subpart A--Administration and Enforcement

Sec. 435.101 Scope and general requirements.

101.1 Title. This part shall be known as the Energy Efficiency

Code for New Federal Residential Buildings and is referred to herein as

``this part.''

101.2 Purpose. The provisions of this part provide minimum

standards for energy efficiency for the design of new Federal

residential buildings. The performance standards are designed to

achieve the maximum practicable cost-effective improvements in energy

efficiency and increases in the use of non-depletable sources of

energy. It is intended that these provisions provide flexibility to

permit the use of innovative approaches and techniques to achieve

efficient utilization of energy. This part also establishes minimum

requirements for the control of radon in new Federal residential

buildings.

101.3 Compliance. This part requires:

101.3.1 Use of a systems approach for the entire building and its

energy-using subsystems which may utilize renewable sources as

established in Subpart D or use of a component performance approach for

various building elements and mechanical systems and components as

established in subpart E; and

101.3.2 Compliance with the radon requirements is established in

subpart G.

101.4 Scope. This part provides design requirements for building

envelopes for adequate thermal resistance and low air leakage and the

design and selection of mechanical, electrical, service water-heating

and illumination systems and equipment which will enable efficient use

of energy in new Federal residential building construction. It applies

to the design and construction of all new Federal residential buildings

that are three stories or less above grade that are not subject to

state or local building codes. Federal residential buildings more than

three stories above grade and all Federal nonresidential buildings must

comply with the Energy Code for Federal Commercial and Multi-Family

High-Rise Residential Buildings.

101.4.1 Radon control. This part also establishes requirements for

control of radon for certain new Federal residential buildings. The

applicability of those requirements is established in section 702.

101.4.2 Building types.

101.4.2.1 Group R Federal residential buildings. For the purposes

of this part, Group R residential buildings include:

(a) Type A-1--Detached one and two family dwellings, and

(b) Type A-2--Other residential buildings, three stories or less in

height.

101.4.2.2 Other buildings. Any buildings and structures not

included in section 101.4.2.1 are not covered by this rule.

101.4.3 Exempt buildings. The building types that are exempt are

as follows: assembly, health, and

101.4.3.1 Buildings and structures or portions thereof whose peak

design rate of energy usage is less than 1.0 W (3.4 Btu/h) or 10.8 W/

m\2\ (1 W/ft\2\) of floor area for all purposes.

101.4.3.2 Buildings and structures or portions thereof which are

neither heated nor cooled.

101.4.4 Application to existing buildings.

101.4.4.1 Additions to existing buildings. Additions to existing

buildings or structures may be made to such buildings or structures

without making the entire building or structure comply. The new

addition shall conform to the provisions of this part as they relate to

new construction only.

Sec. 435.102 Materials and equipment.

102.1 Identification.

102.1.1 General. Materials and equipment shall be identified on

the building plans and specifications in a manner that will allow for a

determination of their compliance with the applicable provisions of

this part.

102.1.2 Building envelope insulation. Building envelope insulation

shall have a thermal resistance (R) identification marker on each piece

of building envelope insulation 0.3048 m (12 in.) or greater in width.

Alternatively, a signed and dated certification for the insulation

installed in each element of the building envelope shall be provided,

listing the type of insulation, the manufacturer, and the R-value. For

blown-in or sprayed insulation, a certification shall be provided that

identifies the initial installed thickness, the settled thickness, the

coverage area, and the number of bags of insulation installed. The

certification shall be posted in a conspicuous place on the job site.

102.1.3 Insulation installation. Roof-ceiling, floor, and wall-

cavity insulation shall be installed to permit inspection of the

manufacturer's R-value identification mark. Alternatively, the

thickness of roof-ceiling insulation that is blown in or sprayed shall

be identified by thickness markers that are labeled in meters (inches)

and installed at least one every 27.9 m2 (300

ft2) of attic space. The markers shall be affixed to the

roof trusses or ceiling joists and marked with the minimum installed

thickness and minimum settled thickness using numbers 25.4 mm (1 in.)

or greater in height. Each marker shall face the attic access opening.

The thickness of installed insulation shall meet or exceed the minimum

installed thickness shown by the marker.

102.2 Maintenance information. Required regular maintenance

actions shall be clearly stated on a readily accessible label. Such

label may be limited to identifying, by title or publication number,

the operation and maintenance manual for that particular model and type

of product. Maintenance instructions shall be furnished for equipment

which requires preventive maintenance for efficient operation.

[[Page 24179]]

102.3 Fenestration product rating, certification, and labeling.

Fenestration products (windows, doors, and skylights) purchased by the

Federal government shall have assigned U-values. If tested for U-value,

the U-values of fenestration products (windows, doors, and skylights)

shall be determined in accordance with RS-1, by an accredited,

independent laboratory. The tested U-value of the fenestration product

shall be certified and the certified U-value shall be labeled on a

conspicuous place on the product. Such certified and labeled U-values

shall be accepted for purposes of determining compliance with the

building envelope requirements of this part.

102.3.1 Exception. Where a fenestration product has not been

assigned a U-value in accordance with RS-1 for a particular product

line, that product shall be assigned a default U-value in accordance

with Appendix Tables 102.3.1 and 102.3.2. Product features must be

technically verifiable for the product to qualify for the U-value

associated with those features. Where the existence of a particular

feature cannot be determined with reasonable certainty, the product

shall not receive credit for that feature. Where a composite of

materials from two different product types are used, the product shall

be assigned the higher U-value.

Sec. 435.103 Alternate materials--method of construction, design, or

insulation systems.

103.1 The provisions of this part are not intended to prevent the

use of any material, method of construction, design or insulating

system not specifically prescribed herein, provided that such

construction, design or insulating system has been approved as meeting

the intent of this part.

Sec. 435.104 [Reserved]

Sec. 435.105 [Reserved]

Sec. 435.106 [Reserved]

Sec. 435.107 Precedence.

107.1 When different sections of this part, or a section of this

part and a section of a referenced standard from section 801 of this

part, specify different materials, methods of construction, or other

requirements, the more stringent or restrictive requirement shall

govern. Whenever there is a conflict between a general requirement and

a specific requirement, the specific requirement shall govern.

Sec. 435.108 Life-cycle cost analysis.

108.1 The proposed building design(s) shall be evaluated in

accordance with the requirements of the Federal Energy Management

Program described in subpart A of 10 CFR part 436 to determine its

life-cycle cost.

Subpart B--Definitions

Sec. 435.201 Definitions.

For the purposes of this part, certain abbreviations, terms,

phrases, words and their derivatives shall be set forth in this

section.

Accessible (as applied to equipment). Admitting close approach; not

guarded by locked doors, elevation, or other effective means (see

``Readily accessible'').

Addition. Increase in conditioned floor area.

Air film. Air immediately adjacent to surfaces of building

materials which helps to inhibit heat flow through those materials.

Air transport factor. The ratio of the rate of useful sensible heat

removal from the conditioned space to the energy input to the supply

and return fan motor expressed in consistent units and under the

designated operating conditions.

Attic. A space directly underneath the roof sheathing and directly

above or adjacent to the interior surfaces of the topmost story of a

building that satisfies all of the following conditions:

(1) The structural members comprising the roof are separate and

distinct rafters and ceiling joists or truss assemblies;

(2) The space is ventilated in accordance with the requirements of

the applicable building code;

(3) The clear height from the top of the ceiling joists to the

highest point of the underside of the rafters is greater than 0.762 m

(30 in.); and

(4) The space is provided with a readily accessible access in

accordance with the requirements of the applicable building code.

Automatic. Self-acting, operating by its own mechanism when

actuated by some impersonal influence, as, for example, a change in

current strength, pressure, temperature or mechanical configuration

(see also ``Manual'').

Basement wall. The opaque portion of a wall which encloses one side

of a basement and is partially or totally below grade.

Building code. The legal instrument which is in effect in a state

or unit of general purpose local government, the provisions of which

must be adhered to if a building is to be considered to be in

conformance with law and suitable for occupancy and use.

Building envelope. The elements of a building which enclose

conditioned spaces through which thermal energy may be transferred to

or from the exterior or to or from spaces located in buildings exempted

by the provisions of section 101.4.2.

Comfort air conditioning. The process of treating air so as to

control simultaneously its temperature, humidity, cleanliness, and

distribution to meet requirements of the conditioned space.

Comfort envelope. The area of a psychrometric chart enclosing all

those conditions described in Figure 1 in Standard RS-2 listed in

section 801 as being comfortable.

Conditioned floor area. The horizontal projection of that portion

of interior space which is contained within exterior walls and which is

conditioned directly or indirectly by an energy-using system.

Conditioned space. Space within a building which is provided with

heated and/or cooled air or surfaces and, where required, with

humidification or dehumidification means so as to be capable of

maintaining a space condition falling within the comfort zone set forth

by Standard RS-2 listed in section 801.

Cooled space. Space within a building which is provided with a

positive cooling supply.

Crawl space wall. The opaque portion of a wall which encloses a

crawl space and is partially or totally below grade.

Deadband. The temperature range in which no heating or cooling is

used.

Degree day, cooling. A unit, based upon temperature difference and

time, used in estimating fuel consumption and specifying nominal

cooling load of a building in summer. For any one day, when the mean

temperature is greater than 18.3 deg.C (65 deg.F), there exists as

many degree days as there are Celsius (Fahrenheit) degrees difference

in temperature between the mean temperature for the day and 18.3 deg.C

(65 deg.F).

Degree day, heating. A unit, based upon temperature difference and

time, used in estimating fuel consumption and specifying nominal

heating load of a building in winter. For any one day, when the mean

temperature is less than 18.3 deg.C (65 deg.F), there exists as many

degree days as there are Celsius (Fahrenheit) degrees difference in

temperature between the mean temperature for the day and 18.3 deg.C

(65 deg.F).

Drain tile loop. A continuous length of drain tile or perforated

pipe extending around all or part of the internal or external perimeter

of a basement or crawl space footing.

Dwelling unit. A single housekeeping unit comprised of one or more

rooms providing complete independent living

[[Page 24180]]

facilities for one or more persons, including permanent provisions for

living, sleeping, eating, cooking and sanitation.

Efficiency, HVAC system. The ratio of useful energy output (at the

point of use) to the energy input in consistent units for a designated

time period, expressed in percent.

Energy. The capacity for doing work taking a number of forms which

may be transformed from one into another, such as thermal (heat),

mechanical (work), electrical and chemical in customary units, measured

in kilowatt-hours (kWh) or Kilojoules [British thermal units (Btus)].

Energy source. Electricity, natural gas, propane gas or fuel oil

that is available at a residential building for space heating, space

cooling, service water heating and lighting. See also ``Renewable

energy sources.''

Equipment type. HVAC system equipment or service water heating

equipment that (1) performs a specific function(s) (e.g., space heating

or space heating and service water heating), (2) uses a specific energy

source(s) (e.g., electricity or a ``dual-fuel'' furnace that can use

electricity or natural gas), and (3) employs a specific operational

principle (e.g., direct combustion, heat rejection to air, heat

extraction from ground water). Example: A heat pump water heater is a

different equipment type from an electric resistance water heater.

Exterior envelope. See ``Building envelope.''

Federal agency. Any department, agency, corporation, or other

entity or instrumentality of the executive branch of the Federal

government, including the United States Postal Service, the Federal

National Mortgage Association, and the Federal Home Loan Mortgage

Corporation.

Federal residential building. Any detached one- or two-family

residential dwelling or other residential building or structure, three

stories or less in height, to be constructed or developed for

residential occupancy by, or for the use of, any Federal agency that is

not legally subject to state or local building codes or similar

requirements.

Furnace, duct. A furnace normally installed in distribution ducts

of air conditioning systems to supply warm air for heating and which

depends on a blower not furnished as part of the duct furnace for air

circulation.

Furnace, warm air. A self-contained, indirect-fired or electrically

heated furnace that supplies heated air through ducts to spaces that

require it.

Glazing area. Interior surface area of assemblies that enclose

conditioned space and that contain glazing, such as windows, sliding

glass doors, and skylights, including the frame, sash, curbing,

muntins, and other framing element.

Grade. The finished ground level adjoining the building at all

exterior walls.

Gross area of exterior walls. The normal projection of the building

envelope wall area bounding interior space which is conditioned by an

energy-using system, including opaque wall, window and door area. The

gross area of exterior walls consists of all opaque wall areas,

including between floor spandrels, peripheral edges of floors, window

areas including sash, and door areas, where such surfaces are exposed

to outdoor air, unconditioned spaces, or spaces exempted by section

101.4.2, and where such spaces enclose a heated or mechanically cooled

space, including interstitial areas between two such spaces. For each

basement wall with an average below-grade area less than 50% of its

total wall area, including openings, the entire wall, including the

below-grade portion, is included as part of the gross area of exterior

walls. Nonopaque areas (windows, doors, etc.) of all basement walls are

included in the gross area of exterior walls.

Gross floor area. The sum of the areas of the several floors of the

building, including basements, cellars, mezzanine and intermediate

floored tiers and penthouses of headroom height, measured from the

exterior faces of exterior walls or from the center line of walls

separating buildings, but excluding:

(a) Covered walkways, open roofed-over areas, porches and similar

spaces.

(b) Pipe trenches, exterior terraces or steps, chimneys, roof

overhangs and similar features.

Group R Federal residential buildings. For the purpose of this

part, Group R Federal residential buildings include:

(a) Type A-1--Detached one and two family dwellings; and,

(b) Type A-2--Other Federal residential buildings, three stories or

less in height.

Heat. The form of energy that is transferred by virtue of a

temperature difference or a change in state of a material.

Heat trap. An arrangement of piping connecting to a hot water

heater such that the piping makes an inverted ``U'' just before

connecting to the heater fittings. Any other arrangement, including a

commercially available heat trap, which effectively restricts the

natural tendency of hot water to rise also qualifies as a heat trap.

Heated slab. Slab-on-grade construction in which the heating

elements or hot air distribution system is in contact with or placed

within the slab or in the subgrade.

Heated space. Space within a building which is provided with a

positive heat supply. Finished living space within a basement with

registers or heating devices designed to supply heat to a basement

space shall automatically define that space as heated space.

Humidistat. A regulatory device, actuated by changes in humidity,

used for automatic control of relative humidity.

HVAC. Heating, ventilating and air conditioning.

HVAC system. The equipment, distribution network, and terminals

that provide, either collectively or individually, the processes of

heating, ventilating, or air conditioning to a building.

HVAC system components. HVAC system components provide, in one or

more factory-assembled packages, means for chilling and/or heating

water with controlled temperature for delivery to terminal units

serving the conditioned spaces of the building. Types of HVAC system

components include, but are not limited to, water chiller packages,

reciprocating condensing units and water source (hydronic) heat pumps

(see ``HVAC system equipment'').

HVAC system efficiency. See ``Efficiency, HVAC system.''

HVAC system equipment. HVAC system equipment provides, in one

(single package) or more (split system) factory-assembled packages,

means for air circulation, air cleaning, air cooling with controlled

temperature and dehumidification, and, optionally, either alone or in

combination with a heating plant, the functions of heating and

humidifying. The cooling function may be either electrically or heat

operated and the refrigerant condenser may be air, water or

evaporatively cooled. Where the equipment is provided in more than one

package, the separate packages shall be designed by the manufacturer to

be used together. The equipment may provide the heating function as a

heat pump or by the use of electric or fossil-fuel-fired elements. (The

word ``equipment'' used without modifying adjective may, in accordance

with common industry usage, apply either to HVAC system equipment or

HVAC system components.)

Infiltration. The uncontrolled inward air leakage through cracks

and interstices in any building element and around windows and doors of

a

[[Page 24181]]

building caused by the pressure effects of wind and/or the effect of

differences in the indoor and outdoor air density.

Life-cycle cost. The total discounted cost of owning, operating,

and maintaining a building or piece of equipment over its useful life

(including its fuel, energy, labor, and replacement components)

determined on the basis of a systematic evaluation except that in the

case of leased buildings, the life-cycle cost shall be calculated over

the effective remaining term of the lease.

Manual. Capable of being operated by personal intervention (see

``Automatic'').

Multi-family dwelling. A building containing three or more dwelling

units.

Opaque areas. All exposed areas of a building envelope which

enclose conditioned space, except openings for windows, skylights,

doors and building service systems.

Outdoor air. Air taken from the outdoors and, therefore, not

previously circulated through the system.

Packaged terminal air conditioner. A factory-selected wall sleeve

and separate unencased combination of heating and cooling components,

assemblies or sections intended for mounting through the wall to serve

a single room or zone. It includes heating capability by hot water,

steam, or electricity.

Packaged terminal heat pump. A packaged terminal air conditioner

capable of using the refrigeration system in a reverse cycle or heat

pump mode to provide heat.

pCi/L. The abbreviation for ``picocuries per liter,'' which is used

as a measure for radon concentrations in air. A picocurie is one-

trillionth (10-12) of a curie. A ``curie'' is a commonly

used measurement of radioactivity.

Positive cooling supply. Mechanical cooling deliberately supplied

to a space such as through a supply register. Also, mechanical cooling

indirectly supplied to a space through uninsulated surfaces of space-

cooling components, such as evaporator coil cases and cooling

distribution systems which continually maintain air temperatures within

the space of 29.4 deg.C (85 deg.F) or lower during normal operation.

To be considered exempt from inclusion in this definition, such

surfaces shall comply with the insulation requirements of this part.

Positive heat supply. Heat deliberately supplied to a space by

design, such as a supply register, radiator or heating element. Also,

heat indirectly supplied to a space through uninsulated surfaces of

service water heaters and space heating components, such as furnaces,

boilers and heating and cooling distribution systems which continually

maintain air temperature within the space of 10 deg.C (50 deg.F) or

higher during normal operation. To be considered exempt from inclusion

in this definition, such surfaces shall comply with the insulation

requirements of this part.

Proposed design. A building design submitted in response to a

request for proposals for the construction of a new Federal residential

building.

Readily accessible. Capable of being reached quickly for operation,

maintenance, removal, or inspection, without requiring the need to

climb over or remove obstacles or to resort to portable ladders or

chairs (see ``Accessible'').

Renewable energy sources. Sources of energy (excluding minerals)

derived from incoming solar radiation, including natural daylighting

and photosynthetic processes; from phenomena resulting therefrom,

including wind, waves and tides, lake or pond thermal differences; and

from the internal heat of the earth, including nocturnal thermal

exchanges.

Reset. Adjustment of the set point of a control instrument to a

higher or lower value automatically or manually to conserve energy.

Roof assembly. All components of the roof/ceiling envelope through

which heat flows, thus creating a building transmission heat loss or

gain, where such assembly is exposed to outdoor air and encloses a

heated or mechanically cooled space. The gross area of a roof assembly

consists of the total interior surface of such assembly, including

skylights exposed to the heated or mechanically cooled space.

Sash crack. The sum of all perimeters of all window sashes, based

on overall dimensions of such parts, expressed in meters (feet). If a

portion of one sash perimeter overlaps a portion of another sash

perimeter, only count the length of the overlapping portions once.

Sensible capacity. The maximum sensible load for which a piece of

equipment is designed to remove or add sensible heat.

Sensible load. The cooling or heating load to remove or add the

sensible heat that causes a temperature change.

Service systems. All energy-using systems in a building that are

operated to provide services for the occupants or processes housed

therein, including HVAC, service water heating, illumination,

transportation, cooking or food preparation, laundering or similar

functions.

Service water heating. Supply of hot water for purposes other than

comfort heating.

Slab-on-grade floor insulation. Insulation around the perimeter of

the floor slab or its supporting foundation when the top edge of the

floor slab perimeter is above the finished grade or 0.305 m (12 in.) or

less below the finished grade.

Soil gas. The gas, present in soil, which may contain radon.

Soil gas retarder. A continuous membrane or other comparable

material used to retard the flow of soil gas into a building.

Solar energy source. Source of natural daylighting and of thermal,

chemical or electrical energy derived directly from conversion of

incident solar radiation.

Standard design. A building designed to exactly meet but not exceed

all requirements in Subpart E of this part.

Submembrane depressurization system. A system designed to achieve a

lower air pressure beneath the soil gas retarder in a crawl space,

relative to crawl space air pressure, resulting in air withdrawal from

under the soil gas retarder either passively (relying on the upward

convective flow of air) or actively (by use of a fan-powered vent).

Subslab depressurization system (active). A piping system that

connects the subslab area with outdoor air, is routed through the

conditioned space of a building, and uses a fan-powered vent to draw

air from beneath the slab.

Subslab depressurization system (passive). A piping system that

connects the subslab area with outdoor air, is routed through the

conditioned space of a building, and relies on the convective flow of

air to draw air from beneath the slab.

Supplementary heater operation. The auxiliary electric resistance

heating device that provides heat which contributes to the operation of

the heat pump when the temperature is too low for the heat pump to

operate independently.

System. A combination of central or terminal equipment or

components and/or controls, accessories, interconnecting means, and

terminal devices by which energy is transformed so as to perform a

specific function, such as HVAC, service water heating or illumination.

Technically verifiable. To visually, physically, or through testing

determine the physical characteristics or specifications of an element,

material, or object.

Terminal element. The means by which the transformed energy from a

system is finally delivered; i.e., registers, diffusers, lighting

fixtures, faucets and similar elements.

Thermal conductance. Time rate of heat flow through a body

(frequently per unit area) from one bounding surface to

[[Page 24182]]

the other for a unit temperature difference between the two surfaces,

under steady conditions (W/m2 deg.C) [Btu/

(hft2 deg.F)].

Thermal resistance (R). The reciprocal of thermal conductance

(m2 deg.C/W)

[(hft2 deg.F)/Btu].

Thermal transmittance (U). The coefficient of heat transmission

(air to air). It is the time rate of heat flow per unit area and unit

temperature difference between the warm side and cold side air films

(W/m2 deg.C) [Btu/

(hft2 deg.F)]. The U-value applies to

combinations of different materials used in series along the heat flow

path, single materials that comprise a building section, cavity air

spaces and surface air films on both sides of a building element.

Thermal transmittance, overall (Uo). The overall

(average) heat transmission of a gross area of exterior building

envelope (W/m2 deg.C) [Btu/

(hft2 deg.F)]. The Uo value

applies to the combined effect of the time rate of heat flow through

the various parallel paths such as windows, doors and opaque

construction areas, comprising the gross area of one or more exterior

building components, such as walls, floors or roof/ceilings.

Thermostat. An automatic control device actuated by temperature and

designed to be responsive to temperature.

Unitary cooling and heating equipment. One or more factory-made

assemblies which include an evaporator or cooling coil, a compressor

and condenser combination, and may include a heating function as well.

Where such equipment is provided in more than one assembly, the

separate assemblies shall be designed to be used together.

Unitary heat pump. One or more factory-made assemblies which

include an indoor conditioning coil, compressor(s) and outdoor coil or

refrigerant-to-water heat exchanger, including means to provide both

heating and cooling functions. When such equipment is provided in more

than one assembly, the separate assemblies shall be designed to be used

together.

Ventilation. The process of supplying or removing air by natural or

mechanical means to or from any space. Such air may have been

conditioned.

Ventilation air. That portion of supply air which comes from

outside (outdoors) plus any recirculated air that has been treated to

maintain the desired quality of air within a designated space. (See

Standard RS-3 listed in section 801 of this part, and definition of

``Outdoor air''.)

Walls. Those portions of the building envelope which are vertical

or tilted at an angle of 30 deg. or less from the vertical plane.

Zone. A space or group of spaces within a building with heating

and/or cooling requirements sufficiently similar so that comfort

conditions can be maintained throughout by a single controlling device.

Subpart C--Design Conditions

Sec. 435.301 Scope.

301.1 General. The criteria of this subpart establishes the design

conditions for use with Subparts D and E of this part.

Sec. 435.302 Thermal design parameters.

302.1 Exterior design conditions. The following design parameters

from table 302.1 shall be used for calculations required under this

part.

Table 302.1

[Exterior design conditions]

----------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------

Winter \1\............................. Design Dry-bulb..................... deg.C ( deg.F).

Summer \1\............................. Design Dry-bulb..................... deg.C ( deg.F).

Design Wet-bulb..................... deg.C ( deg.F).

Degree days, heating \2\

Degree days, cooling \2\

----------------------------------------------------------------------------------------------------------------

\1\ The outdoor design temperature shall be selected from the columns of 97.5% values for winter and 2.5% values

for summer from tables in Standard RS-4 listed in section 801. Adjustments may be made to reflect local

climates which differ from the tabulated temperatures, or local weather experience.

\2\ The degree days, heating [base 18.3 deg.C (65 deg.F)] and cooling [base 18.3 deg.C (65 deg.F)] shall be

selected from NOAA Annual Degree Days to Selected Bases Derived from the 1961--1990 Normals, Standard RS-4

listed in section 801, data available from adjacent military installations, or other sources of local data.

302.2 Interior design conditions.

302.2.1 Indoor Design Temperature. Indoor design temperature shall

be 22.2 deg.C (72 deg.F) for heating and 25.6 deg.C (78 deg.F) for

cooling.

302.2.2 Exception. Other design temperatures may be used for

equipment selection if it results in a lower energy usage.

Sec. 435.303 Mechanical ventilation criteria.

303.1 Ventilation. Ventilation air shall conform to Standard RS-3

listed in section 801. The minimum column value of Standard RS-3 for

each type of occupancy shall be used for design. The ventilation

quantities specified in section 6 of Standard RS-3 are for 100% outdoor

air ventilating systems.

303.1.1 Exception. If outdoor air quantities other than those

specified in Standard RS-3 are used or required because of special

occupancy or process requirements, source control of air contamination,

health and safety or other standards, the required outdoor air

quantities shall be used as the basis for calculating the heating and

cooling design loads.

Subpart D--Design by Systems Analysis; Design Utilizing Renewable

Energy Sources

Sec. 435.401 Scope.

401.1 General. This subpart establishes design requirements based

on a systems analysis of total energy use by a new Federal residential

building, including all of its systems. These design requirements may

be applied as an alternative to the component performance requirements

established in subpart E.

Sec. 435.402 Systems analysis.

402.1 Energy analysis. Compliance with this subpart requires an

analysis of the annual energy usage, hereinafter called an annual

energy analysis. The proposed building shall utilize a design that is

demonstrated, through technically valid and documented calculations, to

have equal or lower annual energy use and equal or lower life-cycle

costs than the standard design.

(a) A building designed in accordance with this subpart complies

with this part if the calculated annual energy usage and life-cycle

costs are not greater than a similar building (defined as a ``standard

design'') with building thermal envelope components and mechanical

systems and equipment used to provide heating, ventilating, and air-

conditioning designed in accordance with subpart E.

[[Page 24183]]

(b) For a proposed building to be considered similar to a

``standard design,'' the proposed building shall have the same

conditioned floor area, ratio of thermal envelope area to conditioned

floor area, exterior design conditions, occupancy, climate data, and

usage operational schedule.

(c) The proposed design shall use the same energy source(s) for

space heating, space cooling, and domestic water heating as the

standard design (identified in subpart E).

402.1.1 Input values for Group R buildings. The input values/

assumptions from tables 402.1.1a through 402.1.1g shall be used in

calculating the annual energy usage.

Table 402.1.1a

[Glazing systems]

------------------------------------------------------------------------

Input Assumptions

-------------------------------------------------------------------------

Design Parameter Standard Design Proposed Design

------------------------------------------------------------------------

Glazing Orientation.............. Window area of Window area

proposed house, 25% oriented as

on North, South, proposed

East, and West design.

Exterior walls..

Shading.......................... Draperies shall be Any exterior

assumed to be shading

closed during provided by

period of proposed

mechanical air design.

conditioner

operation..

------------------------------------------------------------------------

Table 402.1.1b

[Heat storage (thermal mass)]

------------------------------------------------------------------------

------------------------------------------------------------------------

Internal mass.................. 39.0 kg/m\2\ (8 lb/ft \2\)

Structural mass................ 17.1 kg/m\2\ (3.5 lb/ft \2\)

------------------------------------------------------------------------

Table 402.1.1c

[Building thermal envelope--surface areas and volume]

------------------------------------------------------------------------

Design parameter Input assumptions

------------------------------------------------------------------------

Floor, walls, ceiling.................. The floor, walls, and ceiling

areas for both the standard

and proposed design(s) shall

be equal.

Foundation and floor type.............. The foundation and floor type

for both the standard and the

proposed design(s) shall be

equal.

Glazings, including skylights.......... The area of glazing in the

standard design shall not be

greater than the area of

glazing in the proposed

design(s). The glazing U-value

of the standard design shall

be selected to permit

calculated Uo-wall compliance

of the standard design.

Glazing area in the standard

design shall not be provided

with extra shading beyond

shading that is provided by

typical construction

practices--such as roof

overhangs. Energy performance

impacts of added shading for

glazing areas may be accounted

for in the proposed design(s)

for a specific building.

Results from shading

calculation on one proposed

building shall not be used for

groups of buildings.

Doors of A-1 structures................ The standard design shall have

at least 3.7 m \2\ (40 ft \2\)

of door area.

Building Volume........................ The volumes of both the

standard and proposed

design(s) shall be equal.

------------------------------------------------------------------------

Table 402.1.1d

[Thermostat (constants)]

------------------------------------------------------------------------

Design parameter Input value

------------------------------------------------------------------------

Heating Set Point..................... 20.0 deg.C (68 deg.F).

Cooling Set Point..................... 25.6 *C (78 *F).

Night Set Back........................ 15.6 *C (60 *F).

Set Back Duration..................... 7 hours.

Number of Set-back Periods............ 1 (night time).

Maximum number of zones............... 2.

Number of thermostats per zone........ 1.

------------------------------------------------------------------------

Table 402.1.1e

[Internal Sensible Heat Gains (Constants)]

------------------------------------------------------------------------

Unit type Input value

------------------------------------------------------------------------

A-1 Units.......................... 440 W (1,500 Btu/h)

A-2 Units.......................... 879 W (3,000 Btu/h)

------------------------------------------------------------------------

Table 402.1.1f

[Domestic Water Heater (Constant, Calculation)]

------------------------------------------------------------------------

Design parameter Input value

------------------------------------------------------------------------

Temperature set point.................. 49 deg.C (120 deg.F)

Daily hot water consumption............ Liters=113.7 x n-units+(37.9 x

n-bedrooms); [Gallons=(30 x n-

units)+(10 x n-bedrooms)]

------------------------------------------------------------------------

Note:

n-units=number of living units in proposed design(s)

n-bedrooms=number of bedrooms in each living unit.

Table 402.1.1g

[Distribution System Loss Factors]

------------------------------------------------------------------------

Duct Location

-------------------------------------------------------------------------

Mode Outside Inside

------------------------------------------------------------------------

Heating.............................................. 0.75 1.00

Cooling.............................................. 0.80 1.00

------------------------------------------------------------------------

402.1.2 If the proposed design takes credit for reduced air

changes per hour levels, documentation of measures providing such

reduction, or results of a post-construction blower-door test shall be

demonstrated using Standard RS-5 listed in section 801.

402.1.3 Passive solar building designs shall have fixed external

shading, operable internal or external shading or other shading

technologies to limit excessive summer cooling energy gains to the

building interior.

402.1.4 Passive solar buildings shall utilize at least 919 kJ/

deg.C (45 Btu/ deg.F) of additional thermal mass, per m2

(ft\2\) of added glass area, when added south-facing glass area exceeds

33% of the total glass area in walls.

402.1.5 Site Weather Data (constants).

402.1.5.1 The typical meteorological year (TMY), or its ``ersatz''

equivalent, from the National Oceanic and Atmospheric Administration

(NOAA), or an approved equivalent, for the closest available location

shall be used.

402.1.6 The HVAC System Efficiency, for heating and cooling mode,

as identified in 10 CFR part 430 shall be proportionally adjusted for

those portions of the ductwork located outside or inside the

conditioned space using the values shown above, in accordance with

equation 402.1a and table 402.1g:

(Equation 402.1.6a)

[[Page 24184]]

Total Adjusted System Efficiency=Equipment Efficiency x Distribution

Loss Factor x percent of ducts outside+Equipment Efficiency x

Distribution Loss Factor x percent of ducts inside.

402.1.7 Air infiltration. Air changes per hour for the standard

design is 0.5 (for purposes of calculation only).

402.2 Design. The energy usage of the standard design and the

proposed design shall be compared as follows:

(a) The comparison shall be expressed as joule per square meter

(Btu input per square foot) of gross floor area per year at building

site.

(b) If the proposed design results in an increase in usage of one

energy source and a decrease in another energy source, even though

similar sources are used for similar purposes, the difference in each

energy source shall be converted to equivalent energy units for

purposes of comparing the total energy used.

(c) The different energy sources shall be compared on the basis of

energy use at the site where: 1 kWh=3,413 Btu.

402.3 Analysis procedure. The analysis of the annual energy usage

of the standard design and the proposed design(s) shall meet the

following criteria:

(a) The building heating/cooling load calculation procedure used

for annual energy usage analysis shall be detailed enough to evaluate

the effect of factors specified in section 402.4.

(b) The calculation procedure used to simulate the operation of the

building and its service systems through a full-year operating period

shall evaluate the effect of system design, climatic factors,

operational characteristics, and mechanical equipment on annual energy

usage. Manufacturer's data or comparable field test data shall be used

when available in the simulation of systems and equipment. The

calculation procedure shall be based upon 8,760 hours of operation of

the building and its service systems and shall utilize the design

methods specified in Standards RS-4, -6, and -7 listed in section 801.

402.4 Calculation procedures. The calculation procedure shall

cover the following items:

(a) Design requirements--Environmental requirements as required in

subpart C.

(b) Climatic data--Coincident hourly data for temperatures, solar

radiation, wind and humidity of typical days in the year representing

seasonal variation.

(c) Building data--Orientation, size, shape, mass, air, moisture

and heat transfer characteristics.

(d) Operational characteristics--Temperature, humidity,

ventilation, illumination, control mode for occupied and unoccupied

hours.

(e) Mechanical equipment--Design capacity, part load profile.

(f) Building loads--Internal heat generation, lighting, equipment,

number of people during occupied and unoccupied periods.

402.4.1 Use of approved calculation tool. The same calculation

tool shall be used to estimate the annual energy usage for space

heating and cooling of the standard design and the proposed design(s).

402.5 Documentation. Proposed design(s) shall have an energy

analysis comparison report providing technical detail on the data used

in and resulting from the comparative analysis to verify that both the

analysis and the designs meet the criteria of section 401 of this part.

402.6 Exception. Proposed design(s) for one and two family

dwellings and multifamily buildings having a conditioned floor area of

465 m\2\ (5,000 ft\2\) or less are exempted from performing an analysis

on a full-year (8760 hours) basis as described in section 402.3(b).

However, comparison of heating, cooling, and service water heating

equipment energy usage between the proposed design(s) and the standard

design shall be provided in accordance with the remaining provisions of

section 402 of this part.

Sec. 435.403 Renewable energy source analysis.

403.1 General. A proposed building utilizing solar, geothermal,

wind or other renewable energy sources for all or part of its energy

source shall meet the requirements of section 402 of this part, except

such renewable energy may be excluded from the total annual energy

usage allowed for the building by that section.

403.1.1 To qualify for this exclusion such renewable energy must

be derived from a specific collection, storage and distribution system.

The solar energy passing through windows shall also be considered as

qualifying if such windows are provided with:

(a) Operable insulating shutters or other devices which, when drawn

or closed, shall cause the window area to reduce maximum outward heat

flow rate to that specified in section 502.3.1; and

(b) The window areas are shaded or otherwise protected from direct

rays of the sun during periods when mechanical cooling is required.

403.1.2 Exclusion shall also be granted for solar energy passing

through windows provided:

(a) The glass is double or triple pane insulating glass with a low-

emittance coating on one or more airspace surfaces of the glass, or

with a low-emittance plastic film suspended in the airspace, and

(b) The glass areas are shaded from direct solar radiation during

periods when mechanical cooling is required.

403.1.3 Other criteria covered in section 402 shall apply to the

proposed design(s) utilizing renewable sources of energy.

403.2 Documentation. An annual energy analysis comparison shall be

prepared comparing the proposed design(s) and the standard design as

specified in section 402. The report shall provide technical detail on

the building and system design(s) and on the data employed in the

comparative analysis sufficient to verify that both the analysis and

the proposed design(s) meet the criteria of sections 402 and 403 of

this part.

403.2.1 The energy derived from renewable sources and the

reduction in conventional energy requirements derived from nocturnal

cooling shall be separately identified from the overall building energy

use. Supporting documentation on the basis of the performance estimates

for the renewable energy sources or nocturnal cooling shall be

demonstrated in the building plans and specifications.

403.2.2 Energy usage must be calculated in accordance with the

design conditions and methods specified in this part.

403.3 Exception. Proposed design(s) for buildings of less than

464m2 (5,000 ft2) of conditioned floor area that

derive a minimum of 30% of their total annual energy usage from

renewable sources or from nocturnal cooling are exempt from performing

the analysis on a full-year (8,760 hours) basis as described in section

402.3(b). However, comparison of heating, cooling, and service water

heating equipment energy usage between the proposed design(s) and the

standard design shall be provided in accordance with the remaining

provisions of sections 402 and 403 of this part.

403.4 Passive solar design analysis. Proposed design(s) using

passive solar heating strategies, such as south window placement

coupled with thermal mass, attached greenhouses or sunspaces, or Trombe

walls, can be analyzed for annual heating and cooling loads using RS-8.

Other methods for analysis of solar design strategies and equipment are

permitted. Note that use of RS-8 provides information on building loads

only; actual energy consumption depends on the equipment

[[Page 24185]]

proposed for installation in the building.

Subpart E--Design by Component Performance Approach

Sec. 435.501 Scope.

501.1 General. This subpart establishes design requirements based

on component performance for new Federal residential buildings. The

design requirements established in subpart D may be applied in lieu of

these requirements.

Sec. 435.502 Building thermal envelope requirements.

502.1 General. The building thermal envelope shall meet the

requirements of table 502.1a. Compliance with these requirements shall

be demonstrated in accordance with section 502.2. To demonstrate

compliance, calculation procedures and information contained in RS-4,

or laboratory test measurements obtained from test methods RS-9, -10, -

11, or -12, or other documented procedures or information, shall be

used.

502.1.1 The proposed design may include the use of thermal mass in

the exterior walls when determining energy use. If the use of thermal

mass is considered appropriate in the design of the exterior walls then

the required UW for exterior walls, covered by section

502.2.1.1 and having a heat capacity greater than or equal to 123 kJ/

m2 deg.K (6 Btu/ft2 deg.F),

shall be less than or equal to the U-value determined by the applicable

heating degree-days and low-mass-wall UW in tables 502.1b,

502.1c, or 502.1d. The column headings in tables 502.1b through 502.1d

are the UW's, as determined by using equation 502.2a and

Appendix Figure 1, for low-mass-walls; wall constructions having a heat

capacity of less than 123 kJ/m2 deg.K (6 Btu/

ft2 deg.F), as determined by equation 502.1a. The

heat capacity of the wall shall be determined by using equation 502.1a

below:

(Equation 502.1a)

HC=w x c

where:

HC=heat capacity of the exterior wall, based on exterior surface area,

W/(m2 deg.K) [Btu/(ft2 deg.F)].

w=mass of the wall, based on exterior surface area, kg/m2

(lb/ft2).

c=specific heat of the exterior wall material, kJ/(kg deg.K)

[Btu/(lb deg.F)].

The specific heat values shall be permitted to be obtained from

Chapter 22 of Standard RS-4.

Table 502.1a \1\

----------------------------------------------------------------------------------------------------------------

Element Mode Type A-1 buildings Type A-2 buildings

----------------------------------------------------------------------------------------------------------------

Walls............................ Heating or cooling....... Uo Uo

Roof/Ceiling..................... Heating or cooling....... Uo Uo

Floors over unheated spaces...... Heating or cooling....... Uo Uo

Heated slab on grade 2 5......... Heating.................. R R

Depth in.\6\ Depth in.\6\

Unheating slab on grade 3 5...... Heating.................. R R

Depth in.\6\ Depth in.\6\

Basement wall 4 5................ Heating or cooling....... U U

Crawl space wall 4 5............. Heating or cooling....... U U

----------------------------------------------------------------------------------------------------------------

\1\ Values shall be determined by using the graphs (Figures 1, 2, 3, 4, 5 and 6) contained in the Appendix of

this part using heating degree days as specified in section 302.

\2\ There are no insulation requirements for heated slabs in locations having less than 278 Celsius heating

degree days (500 Fahrenheit HDD).

\3\ There are no insulation requirements for unheated slabs in locations having less than 1,389 Celsius heating

degree days (2,500 Fahrenheit HDD).

\4\ Basement and crawl space wall U-values shall be based on the wall components and surface air films. Adjacent

soil shall not be considered in the determination of the U-value.

\5\ Typical foundation wall insulation techniques can be found in Standard RS-13.

\6\ Depth of burial measured as described in section 502.2.1.4.

Table 502.1b.--Required Uw for Wall With a Heat Capacity Equal To or Exceeding 123 kJ/(m2 deg.K) [6 Btu/(ft2 deg.F)] With

Insulation Placed on the Exterior of the Wall Mass

--------------------------------------------------------------------------------------------------------------------------------------------------------

UW required for walls with a heat capacity less than 123 kJ/(m2 deg.K) [6 Btu/(ft2

deg.F)] as determined by using equation 502.2a and appendix figure 1

Heating degree days 18.3 deg.C (65 deg.F) -----------------------------------------------------------------------------------------------------------

base 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22

(0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)

--------------------------------------------------------------------------------------------------------------------------------------------------------

0-1111...................................... 1.59 1.47 1.30 1.19 1.02 0.90 0.73 0.62 0.45

(0-2000).................................... (0.28) (0.26) (0.23) (0.21) (0.18) (0.16) (0.13) (0.11) (0.08)

1112-2222................................... 1.53 1.42 1.24 1.13 0.96 0.85 0.73 0.56 0.45

(2001-4000)................................. (0.27) (0.25) (0.22) (0.20) (0.17) (0.15) (0.13) (0.10) (0.08)

2223-3056................................... 1.42 1.30 1.19 1.02 0.90 0.79 0.62 0.51 0.39

(4001-5500)................................. (0.25) (0.23) (0.21) (0.18) (0.16) (0.14) (0.11) (0.09) (0.07)

3056-3611................................... 1.30 1.19 1.07 0.96 0.85 0.68 0.56 0.45 0.34

(5501-6500)................................. (0.23) (0.21) (0.19) (0.17) (0.15) (0.12) (0.10) (0.08) (0.06)

3612-4444................................... 1.24 1.07 0.96 0.85 0.73 0.62 0.51 0.39 0.28

(6501-8000)................................. (0.22) (0.19) (0.17) (0.15) (0.13) (0.11) (0.09) (0.07) (0.05)

>4445....................................... 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22

(>8001)..................................... (0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)

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[[Page 24186]]

Table 502.1

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