# Energy Conservation Standards for Manufactured Housing > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2016-13547 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** June 17, 2016 - **Citation:** 81 FR 39756 ## Text DEPARTMENT OF ENERGY 10 CFR Part 460 [Docket No. EERE-2009-BT-BC-0021] RIN 1904-AC11 Energy Conservation Standards for Manufactured Housing AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of proposed rulemaking and public meeting. SUMMARY: The U.S. Department of Energy (DOE) is publishing a proposed rule to implement the Energy Independence and Security Act of 2007, which directs DOE to establish energy conservation standards for manufactured housing. DOE proposes to establish energy conservation standards for manufactured housing based on the negotiated consensus recommendations of the manufactured housing working group (MH working group). The MH working group's recommendations were based on the 2015 edition of the International Energy Conservation Code (IECC), the impact of the IECC on the purchase price of manufactured housing, total lifecycle construction and operating costs, factory design and construction techniques unique to manufactured housing, and the current construction and safety standards set forth by U.S. Department of Housing and Urban Development. DATES: DOE will accept comments, data, and information regarding this proposed rule before and after the public meeting, but no later than August 16, 2016 DOE will hold a public meeting on Wednesday, July 13, 2016 from 9:00 a.m. to 4:00 p.m. in Washington, DC. ADDRESSES: The public meeting will be held at the U.S. Department of Energy, Forrestal Building, Room 1E-245, 1000 Independence Avenue SW., Washington, DC 20585-0121. To attend, please notify Ms. Brenda Edwards at (202) 586-2945. Please note that foreign nationals visiting DOE Headquarters are subject to advance security screening procedures. Any foreign national wishing to participate in the public meeting should advise DOE as soon as possible by contacting Ms. Brenda Edwards at (202) 586-2945 to initiate the necessary procedures. Any comments submitted must identify the notice title, docket number EERE-2009-BT-BC-0021, and/or the regulatory identifier number (RIN) 1904-AC11. Comments may be submitted using any of the following methods: 1. Federal eRulemaking Portal: www.regulations.gov . Follow the instructions for submitting comments. 2. Email: ManufacturedHousing 2009BC0021@ee.doe.gov . Include docket number EE-2009-BT-BC-0021 and/or RIN 1904-AC11 in the subject line of the message. 3. Mail: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Program Mailstop EE-2J, 1000 Independence Avenue SW., Washington, DC 20585-0121. 4. Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Program, Suite 600, 950 L'Enfant Plaza SW., Washington, DC 20024. Telephone: (202) 586-2945. Due to potential delays in DOE's receipt and processing of mail sent through the U.S. Postal Service, DOE encourages respondents to submit electronically to ensure timely receipt. For detailed instructions on submitting comments and additional information on the rulemaking process, see section V of this document (“Public Participation”). Docket: The docket is available for review at www.regulations.gov and includes Federal Register notices, public comments, meeting transcript summaries, and other supporting documents and materials. All documents in the docket are listed in the regulations.gov index. However, not all documents listed in the index may be publicly available, such as information that is exempt from public disclosure. A link to the docket Web page can be found at: http://www1.eere.energy.gov/buildings/appliance_standards/rulemaking.aspx?ruleid=97 . This Web page contains a link to the docket for this notice on the regulations.gov site. The regulations.gov Web page also contains instructions on how to access all documents, including public comments, in the docket. See section V of the SUPPLEMENTARY INFORMATION for more information on how to submit comments for this rulemaking through regulations.gov. For further information on how to submit or review public comments, participate in the public meeting, or view hard copies of the docket, contact Ms. Brenda Edwards, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, EE-2J, 1000 Independence Avenue SW., Washington, DC 20585-0121; (202) 586-2945; Brenda.Edwards@ee.doe.gov . FOR FURTHER INFORMATION CONTACT: Mr. Joseph Hagerman, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program (EE-2J), 1000 Independence Avenue SW., Washington, DC, 20585; (202) 586-4549; joseph.hagerman@ee.doe.gov . For information on legal issues presented in this document, contact: Ms. Kavita Vaidyanathan, U.S. Department of Energy, Forrestal Building, Office of the General Counsel (GC-33), 1000 Independence Avenue SW., Washington, DC, 20585; (202) 586-0669; kavita.vaidyanathan@hq.doe.gov . DOE proposes to incorporate by reference into part 460 the following industry standards: (1) Manual J—Residential Load Calculation (8th Edition). (2) Manual S—Residential Equipment Selection (2nd Edition). Copies of Manual J and Manual S may be purchased from Air Conditioning Contractors of America, Inc., (ACCA), 2800 S. Shirlington Road, Suite 300, Arlington, VA 22206, 703-575-4477, http://www.acca.org/ . (3) Overall U-Values and Heating/Cooling Loads—Manufactured Homes. Conner C.C., Taylor, Z.T., Pacific Northwest Laboratory, published February 1, 1992. You may purchase a copy of Overall U-Values and Heating/Cooling Loads—Manufactured Homes from http://www.huduser.org/portal/publications/manufhsg/uvalue.html 800-245-2691. For a further discussion of these standards, see section V.N of this document. SUPPLEMENTARY INFORMATION: I. Synopsis of the Proposed Rule A. The Proposed Regulations B. Benefits and Costs to Purchasers of Manufactured Housing C. Manufacturer Impact D. Nationwide Impacts E. Nationwide Environmental Benefits F. Total Benefits and Costs II. Introduction A. Authority B. Background 1. Current Regulation of Manufactured Housing 2. The International Energy Conservation Code 3. Development of the Proposed Rule III. Discussion A. The Basis for the Proposed Standards B. Proposed Energy Conservation Requirements 1. Subpart A: General 2. Subpart B: Building thermal envelope 3. Subpart C: HVAC, service water heating, and equipment sizing C. Other 2015 IECC Specifications 1. Section R302 2. Section R303.1 3. Section R401.3 4. Section R402.4 5. Section R403 6. Section R404 7. Section R405 8. Section R406 9. Chapter 5 10. Chapter 6 D. Crosswalk of Proposed Standards With the HUD Code E. Compliance and Enforcement IV. Economic Impacts and Energy Savings A. Economic Impacts on Individual Purchasers of Manufactured Homes B. Manufacturer Impacts C. Nationwide Impacts D. Nationwide Environmental Benefits E. Total Benefits and Costs V. Regulatory Review A. Executive Order 12866 B. Executive Order 13563 C. Regulatory Flexibility Act D. Paperwork Reduction Act E. National Environmental Policy Act F. Executive Order 13132 G. Executive Order 12988 H. Unfunded Mandates Reform Act I. Family and General Government Appropriations Act J. Executive Order 12630 K. Treasury and General Government Appropriations Act L. Executive Order 13211 M. Section 32 of the Federal Energy Administration Act of 1974 N. Materials Incorporated by Reference VI. Public Participation A. Attendance at Public Meeting B. Procedure for Submitting Prepared General Statements for Distribution C. Conduct of Public Meeting D. Submission of Comments 1. Submitting Comments via Regulations.gov 2. Submitting Comments via Email, Hand Delivery, or Mail. E. Issues on Which DOE Seeks Comment VII. Approval of the Office of the Secretary I. Synopsis of the Proposed Rule A. The Proposed Regulations The Energy Independence and Security Act of 2007 (EISA, Pub. L. 110-140) directs the U.S. Department of Energy (DOE) to establish energy conservation standards for manufactured housing. EISA directs DOE to base the standards on the most recent version of the International Energy Conservation Code (IECC) and any supplements to that document, except where DOE finds that the IECC is not cost-effective or where a more stringent standard would be more cost-effective, based on the impact of the IECC on the purchase price of manufactured housing and on total lifecycle construction and operating costs. See 42 U.S.C. 17071. In accordance with this statutory directive, DOE is proposing energy conservation standards for manufactured housing. These energy conservation standards would be codified in a new part of the Code of Federal Regulations (CFR) under 10 CFR part 460 subparts A, B, and C. Subpart A discusses generally the scope of the proposed rule and provides proposed definitions of key terms. The subpart also would provide manufacturers with a one-year lead time for compliance such that the standards would apply to all manufactured homes manufactured on or after one year following the publication of a final rule. Subpart B would establish requirements related to climate zones and the building thermal envelope of manufactured homes. DOE proposes to base its energy conservation requirements on four climate zones, which generally follow state borders, with some exceptions. Regarding the building thermal envelope, DOE proposes two approaches to compliance. The first is a prescriptive approach that would establish specific requirements for component and fenestration thermal resistance ( R -value), thermal transmittance ( U -factor), and solar heat gain coefficient (SHGC). The second is a performance-based approach that would establish a maximum overall thermal transmittance ( U o ) requirement for the building thermal envelope and additional U -factor and SHGC requirements. Subpart B also would include provisions for determining U -factor, R -value, SHGC, and U o . Finally, subpart B would establish prescriptive requirements for insulation and sealing the building thermal envelope to limit air leakage. Subpart C would establish requirements related to duct leakage; heating, ventilation, and air conditioning (HVAC); service hot water systems; mechanical ventilation fan efficacy; and heating and cooling equipment sizing. B. Benefits and Costs to Purchasers of Manufactured Housing As explained in greater detail in section IV of this document and in chapter 9 of the technical support document (TSD) accompanying this proposed rule, DOE estimates that benefits to manufactured homeowners in terms of lifecycle cost (LCC) savings and energy cost savings under the proposed rule would outweigh the potential increase in purchase price for manufactured homes. As presented in Table I.1, DOE estimates that the average purchase price of a manufactured home under the proposed rule would increase as much as $2,423 for a single-section and $3,745 for a multi-section manufactured home as a result of the increased construction costs associated with energy conservation improvements. Table I.1—National Average Manufactured Housing Purchase Price (and Percentage) Increases Under the Proposed Rule Single-section ($) (%) Multi-section ($) (%) Climate Zone 1 2,422 5.3 3,748 4.5 Climate Zone 2 2,348 5.1 3,668 4.4 Climate Zone 3 2,041 4.5 2,655 3.2 Climate Zone 4 2,208 4.8 2,877 3.4 National Average 2,226 4.9 3,109 3.7 As explained in more detail in section IV.A of this document and in chapter 9 of the TSD, Table I.2 presents the estimated national average LCC savings and energy savings that a manufactured homeowner would experience under the proposed rule as compared to a manufactured home constructed in accordance with the minimum requirements of the existing HUD Code at 24 CFR part 3282. Table I.2 and Figure I.1 present the nationwide average simple payback period (purchase price increase divided by first year energy cost savings) under the proposed rule. Table I.2—National Average Per-Home Cost Savings Under the Proposed Rule Single- section Multi- section Lifecycle Cost Savings (30-Year Lifetime) $3,211 $4,625. Annual Energy Cost Savings in 2015 dollars $345 $490. Simple Payback 7.1 years 6.9 years. EP17JN16.000 C. Manufacturer Impact As discussed in more detail in section IV.B of this document and chapter 12 of the TSD, the industry net present value (INPV) is the sum of the discounted cash flows to the industry from the announcement year (2016) through the end of the analysis period (2046). Using a real discount rate of 9.2 percent, DOE estimates the base case INPV for manufacturers to be $716.7 million. Under the proposed standards, DOE expects that the INPV will be reduced by 0.7 to 6.8 percent. Industry conversion costs are expected to total $1.6 million. D. Nationwide Impacts As described in more detail in section IV.C of this document and chapter 11 of the TSD, DOE's national impact analysis (NIA) projects a net benefit to the nation as a whole as a result of the proposed rule in terms of national energy savings (NES) and the net present value (NPV) of expected total manufactured homeowner costs and savings as compared with manufactured homes built to the minimum standards established in the HUD Code. As part of its NIA, DOE has projected the energy savings, operating cost savings, incremental equipment costs, and NPV of manufactured homeowner benefits for manufactured homes sold in a 30-year period from 2017 through 2046. The NIA builds off the LCC analysis discussed by the MH working group by aggregating results for all affected shipments over a 30-year period. All NES and percent energy savings calculations are relative to a no regulatory action alternative, which would maintain energy conservation requirements at the levels established in the existing HUD Code. Table I.3 and Table I.4 illustrate the cumulative NES over the 30-year analysis period under the proposed rule on a full-fuel-cycle (FFC) energy savings basis. FFC energy savings apply a factor to account for losses associated with generation, transmission, and distribution of electricity, and the energy consumed in extracting, processing, and transporting or distributing primary fuels. NES differ among the different climate zones because of varying energy conservation requirements and varying shipment projections in each climate zone. All NES and percent energy savings calculations are relative to a no regulatory action alternative, which would maintain energy conservation requirements at the levels established in the existing HUD Code. Table I.3—Cumulative National Energy Savings Including Full-Fuel-Cycle of Manufactured Homes Purchased 2017-2046 With a 30-Year Lifetime Single-section quadrillion British thermal units (BTUs) (quads) Multi-section quadrillion BTUs (quads) Climate Zone 1 0.179 0.294 Climate Zone 2 0.130 0.245 Climate Zone 3 0.272 0.474 Climate Zone 4 0.303 0.416 Total 0.884 1.428 Table I.4—Percentage of Cumulative National Energy Savings Including Full-Fuel-Cycle of Manufactured Homes Purchased 2017-2046 With a 30-Year Lifetime Single-section (%) Multi-section (%) Climate Zone 1 25.3 29.9 Climate Zone 2 25.4 30.6 Climate Zone 3 26.0 28.1 Climate Zone 4 25.4 26.6 Total 25.6 28.3 Table I.5 and I.6 illustrate the NPV of customer benefits over the 30-year analysis period under the proposed rule for a discount rate of 7 percent and 3 percent, respectively. The NPV of customer benefits differ among the four climate zones because of differing initial costs and corresponding operating cost savings, as well as differing shipment projections in each climate zone. Under the proposed rule, all climate zones have a positive NPV for both discount rates. Table I.5—Net Present Value of Customer Benefits for Manufactured Homes Purchased 2017-2046 With a 30-Year Lifetime at a 7% Discount Rate Single-section (billion 2015$) Multi-section (billion 2015$) Climate Zone 1 0.19 0.34 Climate Zone 2 0.16 0.35 Climate Zone 3 0.39 0.74 Climate Zone 4 0.52 0.74 Total 1.26 2.18 Table I.6—Net Present Value of Customer Benefits for Manufactured Homes Purchased 2017-2046 With a 30-Year Lifetime at a 3% Discount Rate Single-section (billion 2015$) Multi-section (billion 2015$) Climate Zone 1 0.66 1.16 Climate Zone 2 0.54 1.10 Climate Zone 3 1.22 2.26 Climate Zone 4 1.60 2.24 Total 4.03 6.75 E. Nationwide Environmental Benefits As discussed in section IV.D of this document and in the NIA included in chapter 11 of the TSD accompanying this proposed rule, DOE's analyses indicate that the proposed rule would reduce overall demand for energy in manufactured homes. The proposed rule also would produce environmental benefits in the form of reduced emissions of air pollutants and greenhouse gases associated with electricity production. DOE estimates that 18.1 million metric tons of carbon dioxide emissions would be avoided through the end of 2030 as a result of the proposed rule. Emissions avoided under the proposed rule are related to the energy savings that would be achieved within manufactured homes. DOE estimates that, under the proposed rule, 2.3 quadrillion Btu (quads) of FFC energy would be saved relative to manufactured homes constructed under the minimum requirements of the HUD Code over a 30-year analysis period. DOE estimates reductions in emissions of six pollutants associated with energy savings: Carbon dioxide (CO 2 ), mercury (Hg), nitric oxide and nitrogen dioxide (NO X ), sulfur dioxide (SO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O). These emissions reductions are referred to as “site” emissions reductions. Furthermore, DOE estimates reductions in emissions associated with the production of these fuels (including extracting, processing, and transporting these fuels to power plants or manufactured homes). These emissions reductions are referred to as “upstream” emissions reductions. Together, site emissions reductions and upstream emissions reductions account for the FFC. Table I.7 lists the emissions reductions under the proposed rule for both single-section and multi-section manufactured homes. Table I.7—Emissions Reductions Associated With Electricity Production for Manufactured Homes Purchased 2017-2046 With a 30-Year Lifetime Pollutant Single- section Multi- section Site Emissions Reductions CO 2 (million metric tons) 56.5 91.1 Hg (metric tons) 0.0904 0.146 NO X (thousand metric tons) 223 356 SO 2 (thousand metric tons) 27.6 44.4 CH 4 (thousand metric tons) 3.78 6.09 N 2 O (thousand metric tons) 0.632 1.02 Upstream Emissions Reductions CO 2 (million metric tons) 4.01 6.45 Hg (metric tons) 0.000944 0.00153 NO X (thousand metric tons) 51.8 83.2 SO 2 (thousand metric tons) 0.615 0.991 CH 4 (thousand metric tons) 239 385 N 2 O (thousand metric tons) 0.0294 0.0474 Total Emissions Reductions CO 2 (million metric tons) 60.5 97.6 Hg (metric tons) 0.0913 0.148 NO X (thousand metric tons) 275 439 SO 2 (thousand metric tons) 28.2 45.4 CH 4 (thousand metric tons) 243 391 N 2 O (thousand metric tons) 0.661 1.07 Additionally, DOE has considered the estimated monetary benefits likely to result from the reduced emissions of CO 2 and NO X that would be expected to result from the proposed rule. DOE calculated the monetary values for each of these emissions reductions using the social cost of carbon (SCC) model, which estimates the monetized damages associated with an incremental increase in carbon emissions within a given year. The SCC is intended to account for, but is not limited to, changes in net agricultural productivity, human health, property damages from increased flood risk, and the value of ecosystem services. Table I.8 provides the NPV of monetized emissions benefits from CO 2 and NO X under the proposed rule. DOE estimates that the monetized benefits from emissions reductions associated with the proposed rule would be $5,541.5 million ($4,731.4 million in CO 2 emissions reductions plus $810.1 million in NO X emissions reductions) over a 30-year analysis period at the 3 percent discount rate and the CO 2 cost associated with the average SCC case. Table I.8—Net Present Value of Monetized Benefits From CO 2 and NO X Emissions Reductions Under the Proposed Rule Monetary benefits Discount rate (%) Net present value (million 2015$) Single- section Multi- section CO 2 , Average SCC Case * 5 368.2 593.7 CO 2 , Average SCC Case * 3 1,810.9 2,920.5 CO 2 , Average SCC Case * 2.5 2,925.0 4,717.3 CO 2 , 95th Percentile SCC Case * 3 5,581.5 9,001.5 NO X Reduction at $2,755/metric ton * 3 311.5 498.6 7 119.8 191.9 * The CO 2 values represent global monetized values (in 2015$) of the social cost of CO 2 emissions reductions for manufactured homes shipped from 2017-2046 with a 30-year lifetime under several different scenarios of the SCC model. The “average SCC case” refers to average predicted monetary savings as predicted by the SCC model. The “95th percentile case” refers to values calculated using the 95th percentile impacts of the SCC model, which accounts for greater than expected environmental damages. The value for NO X (in 2015$) is the average of the low and high values used in DOE's analysis. F. Total Benefits and Costs As explained in greater detail in section IV of this document and chapter 15 of the TSD, Table I.9 presents the total benefits and costs to manufactured homeowners associated with the proposed rule, expressed in terms of annualized values. 1 1 As stated in this preamble, DOE used a two-step calculation process to convert the time-series of costs and benefits into annualized values. First, DOE calculated a present value in 2015, the year used for discounting the net present value of total consumer costs and savings, for the time-series of costs and benefits using discount rates of three and seven percent for all costs and benefits except for the value of CO 2 reductions. For the latter, DOE used a range of discount rates, as shown in Table I.8. From the present value, DOE then calculated the fixed annual payment over a 30-year period, starting in 2017 that yields the same present value. The fixed annual payment is the annualized value. Although DOE calculated annualized values, this does not imply that the time-series of cost and benefits from which the annualized values were determined would be a steady stream of payments. Table I.9—Total Annualized Benefits and Costs to Manufactured Homeowners Under the Proposed Rule Discount rate (%) Monetized (million 2015$/year) Primary estimate ** Low estimate ** High estimate ** Benefits * Operating (Energy) Cost Savings 7 3 516 843 400 617 688. 1,191. CO 2 , Average SCC Case *** 5 63 46 85. CO 2 , Average SCC Case *** 3 241 176 331. CO 2 , Average SCC Case *** 2.5 365 266 503. CO 2 , 95th Percentile SCC Case *** 3 744 543 1,022. NO X Reduction at $2,755/metric ton *** 7 3 25 41 20 31 32. 56. Total (Operating Cost Savings, CO 2 Reduction and NO X Reduction) 7 plus CO 2 range 7 604 to 1,285 783 466 to 962 596 805 to 1,742. 1,052. 3 1,126 824 1,578. 3 plus CO 2 range 947 to 1,628 694 to 1,191 1,332 to 2,269. Costs * Incremental Purchase Price Increase 7 3 220 277 165 192 285. 378. Net Benefits/Costs * Total (Operating Cost Savings, CO 2 Reduction and NO X Reduction, Minus Incremental Cost Increase to Homes) 7 plus CO 2 range 7 384 to 1,065 563 301 to 797 431 520 to 1,457. 767. 3 849 632 1,200. 3 plus CO 2 range 670 to 1,351 502 to 999 954 to 1,891. * The benefits and costs are calculated for homes shipped in 2017-2046. ** The Primary, Low, and High Estimates utilize forecasts of energy prices from the 2015 AEO Reference case, Low Economic Growth case, and High Economic Growth case, respectively. *** The CO 2 values represent global monetized values (in 2015$) of the social cost of CO 2 emissions reductions over the analysis period under several different scenarios of the SCC model. The “average SCC case” refers to average predicted monetary savings as predicted by the SCC model. The “95th percentile case” refers to values calculated using the 95th percentile impacts of the SCC model, which accounts for greater than expected environmental damages. The value for NO X (in 2015$) is the average of the low and high values used in DOE's analysis. II. Introduction A. Authority Section 413 of EISA directs DOE to: Establish standards for energy conservation in manufactured housing; • Provide notice of and an opportunity for comment on the proposed standards by manufacturers of manufactured housing and other interested parties; • Consult with the Secretary of HUD, who may seek further counsel from the Manufactured Housing Consensus Committee (MHCC); and • Base the energy conservation standards on the most recent version of the IECC and any supplements to that document, except where DOE finds that the IECC is not cost effective or where a more stringent standard would be more cost effective, based on the impact of the IECC on the purchase price of manufactured housing and on total lifecycle construction and operating costs. Section 413 of EISA also provides that DOE may: Consider the design and factory construction techniques of manufactured housing; • Base the climate zones under the proposed rule on the climate zones established by HUD in 24 CFR part 3280 rather than the climate zones under the IECC; and • Provide for alternative practices that, while not meeting the specific standards established by DOE, result in net estimated energy consumption equal to or less than the specific energy conservation standards as proposed. DOE is directed to update its standards not later than one year after any revision to the IECC. Finally, section 413 of EISA authorizes DOE to impose civil penalties on any manufacturer that violates a provision of part 460. B. Background 1. Current Regulation of Manufactured Housing Section 413 of EISA provides DOE with the authority to regulate energy conservation in manufactured housing, an area of the building construction industry traditionally regulated by HUD. HUD has regulated the manufactured housing industry since 1976, when it first promulgated the HUD Code. The purpose of the HUD Code has been to reduce personal injuries, deaths, property damage, and insurance costs, and to improve the quality, durability, safety, and affordability of manufactured homes. See 42 U.S.C. 5401(b). The HUD Code includes requirements related to the energy conservation of manufactured homes. Specifically, Subpart F of the HUD Code, entitled “Thermal Protection,” establishes requirements for U o of the building thermal envelope. U o is a measurement of the heat loss or gain rate through the building thermal envelope of a manufactured home; therefore, a lower U o corresponds with a more insulated building thermal envelope. The HUD Code contains maximum requirements for the combined U o value of walls, ceilings, floors, fenestration, and external ducts within the building thermal envelope for manufactured homes installed in different climate zones. See 24 CFR 3280.507(a). The HUD Code also provides an alternate pathway to compliance that allows manufacturers to construct manufactured homes that meet adjusted U o requirements based on the installation of high-efficiency heating and cooling equipment in the manufactured home. See id. 3280.508(d). Moreover, Subpart F of the HUD Code establishes requirements to reduce air leakage through the building thermal envelope. See id. 3280.505. Subpart H of the HUD Code, entitled “Heating, Cooling and Fuel Burning Systems,” establishes requirements for sealing air supply ducts and for insulating both air supply and return ducts. See id. 3280.715(a). R -value is the measure of a building component's ability to resist heat flow (thermal resistance). A higher R -value represents a greater ability to resist heat flow and generally corresponds with a thicker level of insulation. The HUD Code contains no requirements for fenestration SHGC, mechanical system piping insulation, or installation of insulation. It is important to note that the statutory authority for DOE's rulemaking effort is different from the statutory authority underlying the HUD Code. EISA directs DOE to establish energy conservation standards for manufactured housing without reference to existing HUD Code requirements that also address energy conservation. In development of the proposed regulations, DOE seeks to make every effort to ensure that compliance with this proposed requirements would not impinge a manufacturer from complying with the requirements set forth in the HUD Code. Additionally, DOE is seeking to avoid any potential redundancy between the proposed requirements and the HUD Code. Accordingly, section III.D of this document charts the relationship between the energy conservation requirements in the HUD Code and the proposed DOE requirements. Given the level of detail required in analyzing all aspects of energy conservation contained in both the proposed rule and the HUD Code, DOE requests comment on any potential inconsistencies that would result from promulgation of the proposed regulations. 2. The International Energy Conservation Code The statutory authority for this rulemaking requires DOE to base its standards on the most recent version of the IECC and any supplements to that document, except where DOE finds that the IECC is not cost-effective or where a more stringent standard would be more cost-effective, based on the impact of the IECC on the purchase price of manufactured housing and on total lifecycle construction and operating costs. See 42 U.S.C. 17071. The IECC is a nationally recognized model code, developed under the auspices of, and published by, the International Code Council (ICC), which many state and local governments have adopted in establishing minimum design and construction requirements for the energy efficiency of residential and commercial buildings, including site-built residential and modular homes. The IECC is developed through a consensus process that seeks input from industry stakeholders and is updated on a rolling basis, with new editions of the IECC published approximately every three years. The IECC was first published in 1998, and it has been updated continuously since that time. The 2015 edition of the IECC (the 2015 IECC) was published in May 2014. Chapter 4 of the 2015 IECC sets forth specifications for residential energy efficiency, including specifications for building thermal envelope energy conservation, thermostats, duct insulation and sealing, mechanical system piping insulation, circulating hot water system piping, and mechanical ventilation. Chapter 4 of the 2015 IECC was developed for residential buildings generally and are not specific to manufactured housing. To the extent that the HUD Code regulates similar aspects of energy conservation as the 2015 IECC, the 2015 IECC is generally considered to be more stringent than the corresponding requirement in the HUD Code given that many areas of the HUD Code are not updated as frequently as the IECC. 3. Development of the Proposed Rule Manufactured housing accounts for approximately six percent of all homes in the United States. 2 Because the purchase price of manufactured homes often is lower than similarly sized site-built homes, manufactured homes serve as affordable housing options, particularly for low-income families. Nevertheless, the operational costs to the homeowner may not be reflected in the purchase price of the home. Manufactured housing home owners often have higher utility bills than comparably built site-built and modular homes in part due to different criteria for energy conservation and variability among building codes and industry practice. 2 See U.S. Census Bureau, American Housing Survey 2013—National Summary Tables. Establishing robust energy conservation requirements for manufactured homes would result in the dual benefit of substantially reducing manufactured home energy use and easing the financial burden on owners of manufactured homes in meeting their monthly utility expenses. Improved energy conservation standards are expected to provide nationwide benefits of reducing utility energy production levels that would in turn reduce greenhouse gas emissions and other air pollutants. On February 22, 2010, DOE published an advance notice of proposed rulemaking (ANOPR) to initiate the process of developing energy conservation standards for manufactured housing and to solicit information and data from industry and stakeholders. See 75 FR 7556. The ANOPR identified thirteen specific issue areas on which DOE sought additional information. DOE received a total of twelve written comments in response to the ANOPR, all of which are available for public viewing at the regulations.gov Web page. 3 3 The ANOPR comments can be accessed at: http://www.regulations.gov/#!docketDetail;D=EERE-2009-BT-BC-0021 . DOE also has consulted with HUD in developing the proposed requirements and in obtaining input and suggestions that would increase energy conservation in manufactured housing while maintaining affordability. In addition to meeting with HUD on multiple occasions, DOE attended three MHCC meetings, where DOE gathered information from MHCC members. DOE also initiated further discussions with members of the manufactured housing industry following the issuance of the ANOPR, including the Manufactured Housing Institute and several of its member manufacturers, the State of California Department of Housing and Community Development, the State of Georgia Manufactured Housing Division, three private sector third-party primary inspection agencies under the HUD manufactured housing program, and one private sector stakeholder familiar with manufactured housing. A summary of each meeting is available at the regulations.gov Web page. The following section provides a summary of comments DOE received in response to the ANOPR. Generally, the comments can be grouped into five main areas: Climate zones; the basis for the proposed standards; specific building thermal envelope requirements; enforcement of DOE's proposed energy conservation standards; and the need for, and scope of, the proposed rule. Regarding the issue of climate zones, DOE received comments recommending that DOE define climate zones at the county level, possibly based on the climate zones established in the IECC or on a subset of those climate zones to align with the requirements for site-built homes. Generally, these commenters stated that the IECC climate zones are recognized and understood by the manufacturing and regulatory sectors. Conversely, DOE received other comments indicating a preference for retaining the three climate zones established in the HUD Code. DOE also received comments suggesting that DOE consider more refined climate zones in the southern United States, noting the abundance of manufactured homes sold in that region of the country. As discussed in section III.B.2.a) of the document, DOE proposes to base its energy conservation standards on four climate zones. DOE requests comment on the proposed use of four climate zones relative to adopting the three HUD climate zones and whether there are any potential impacts on manufacturing costs, compliance costs, or other impacts, in particular in Arizona, Texas, Louisiana, Mississippi, Alabama, and Georgia, where the agency has proposed two different energy efficiency standards within the same state. DOE received numerous comments suggesting that DOE base its proposed energy conservation standards on the IECC rather than on the energy conservation standards established by HUD. Specifically, one commenter stated that IECC training and related support services would be available if DOE based its energy conservation standards on the IECC that would be absent if DOE used a different basis for the proposed energy conservation standards. Another commenter suggested that the proposed energy conservation standards should be at a minimum as efficient as the requirements contained in the most recent edition of the IECC or better where lifecycle cost effective. One commenter stated that the IECC was not intended to apply to manufactured housing and that DOE should consider altering IECC standards to be compatible with manufactured housing building processes. However, another commenter stated that there are no intrinsic differences between site-built and factory-built construction techniques that would limit DOE from proposing energy conservation standards to the level set forth in the most recent edition of the IECC and beyond. Other commenters discussed specific energy conservation requirements that should be included in the proposed rule, including requiring high-efficiency furnaces, boilers, and heat pump heating in colder climate zones, high-efficiency air conditioners in warmer climate zones, ENERGY STAR appliances, and improved lighting systems, where cost-effective. Commenters also requested that DOE consider requiring R -5 windows, passive solar design, and establishing provisions to address barriers to future technology. Conversely, one commenter stated that the HUD Code balances requirements related to both air leakage and condensation. Other commenters requested that DOE consider the National Fire Protection Association (NFPA) Standard on Manufactured Housing in developing its proposed standards and that DOE also consider certain applicable requirements contained in the International Residential Code. Another commenter suggested that DOE develop standards that would allow above-code programs, such as ENERGY STAR, to build upon the requirements set forth by DOE. DOE also received several comments that manufactured homes should be as energy efficient as site-built and modular homes while asserting that DOE's energy conservation standards be no more stringent than the requirements for site-built housing. However, it also was suggested that DOE consider establishing one or more performance tiers above the minimum DOE energy conservation standards, with associated incentives for manufacturers, to drive the market for high performance manufactured housing. As discussed further in section III.A of this document, DOE proposes to base its energy conservation standards on the 2015 IECC while accounting for the potential effects on purchase price, total lifecycle construction and operating costs, and design and factory construction techniques unique to manufactured homes. With respect to the potential effects of the proposed rule on purchase price and total lifecycle construction and operating costs, DOE received comments providing specific information that assisted DOE in its preliminary economic analyses for developing the proposed requirements. Regarding the issue of home financing, commenters recommended that DOE's economic analysis on financing assume terms of loans similar to those for new site-built homes, accompanied by a three percent discount rate. Other commenters suggested that DOE's economic analyses assume terms of loans that reflect a mix of real estate and personal property loans that are reflective of the market share of each type of loan and that account for historical trends in loans for manufactured housing. Another commenter suggested that DOE account for conventional financing rates of five to seven percent and assume full resale recovery, as recognized by the National Automobile Dealers Association in appraisal value for ENERGY STAR-labeled manufactured homes. It was suggested that DOE account for volume procurement purchasing prices, collect cost data from manufacturers and major suppliers provided in manufactured homes by state and region, and use standard industry mark-ups in conducting its economic analyses. Commenters also stated that any increase in the purchase price of a manufactured home could exacerbate the lack of affordable housing. Commenters further stated that although manufacturers offer manufactured homes that exceed the energy conservation requirements contained in the HUD Code, financing the cost of those additional energy features often is an obstacle to such homes being purchased. Accordingly, it was suggested that DOE apply the same analytical framework that DOE uses for developing energy efficiency standards for appliances in developing the proposed energy conservation standards. Specifically, one commenter suggested that DOE conduct parametric and statistical modeling analyses accounting for various factors, including single-wide versus multi-wide manufactured homes, differences among fuel types, duct locations, eliminating various “trade-offs,” and evaluating solar thermal and photovoltaic systems in establishing the proposed standards. With respect to design and construction techniques unique to manufactured homes, DOE received several comments highlighting that the manufactured housing industry has been producing manufactured homes that exceed the energy conservation requirements contained in the HUD Code. One commenter stated that since 1989, over 100,000 manufactured homes had been built in the Pacific Northwest region of the United States that have an energy efficiency level that complies with the most recent version of the IECC. Another commenter provided specific examples of manufactured homes that exceeded the energy conservation requirements contained in the HUD Code. Indeed, DOE received comments stating that 90 percent of manufactured housing builders had adopted the U.S. Environmental Protection Agency (EPA) ENERGY STAR program for manufactured housing. Another commenter suggested that DOE utilize research results and information from the DOE Building America Program and the Partnership for Advancing Technology in Housing program at HUD in developing the proposed energy conservation standards and in determining the costs and benefits of more stringent standards. It was suggested that DOE also evaluate products such as foam wall sheathing, innovative roof systems, and solar thermal and photovoltaic systems in developing the proposed energy conservation standards, and to obtain information from HVAC equipment manufacturers on available equipment efficiencies specific to manufactured homes. With respect to design and construction techniques unique to manufactured homes, one commenter suggested that DOE adopt the energy efficiency specifications contained in the IECC unless something unique about the production of a manufactured home necessitated a different standard. Another commenter stated that DOE should coordinate with HUD on the development of the proposed rule and to make recommendations to HUD on non-energy-related issues for HUD consideration in updating the HUD Code. Specifically, it was suggested that DOE recognize exterior height and width limitations of manufactured homes in its proposed standards. DOE has attempted to address these comments by proposing thermal performance requirements that are similar to the HUD Code, while proposing other specific energy conservation requirements that are based on the requirements set forth in the 2015 edition of the IECC. DOE also has attempted to address unique aspects of manufactured homes in the proposed rule that would not be addressed by the proposed requirements for overall thermal performance. Regarding specific building thermal envelope requirements, DOE received a number of comments requesting that DOE retain the thermal envelope performance approach set forth in the HUD Code, rather than component prescriptive measures, in order to facilitate application and use of innovative technology and materials. Another commenter suggested that DOE consider HUD's U- factor calculation manual in developing the proposed standards. As discussed in section III.B.2.b) of this document, DOE proposes to establish thermal envelope requirements as a function of the overall thermal transmittance of the building thermal envelope of a manufactured home for consistency with the approach set forth in the HUD Code. DOE also proposes prescriptive requirements as an alternative to the U o requirement. Regarding compliance with, and enforcement of, DOE's proposed energy conservation standards, DOE received a range of comments. First, DOE received comments suggesting that DOE rely on HUD's existing enforcement system rather than develop a separate DOE system of enforcement. Specifically, one commenter suggested that DOE consider using the existing HUD-approved third-party primary inspection agencies to ensure compliance with both HUD and DOE requirements for manufactured housing in order to avoid an increase in manufacturer fees and the creation of a duplicative system of compliance certification. Another commenter suggested that the HUD label be modified to reflect compliance with both the HUD and DOE requirements. Secondly, DOE received a comment that DOE develop a separate compliance certification system that would be independent of the existing HUD certification system. In this regard, it was suggested that DOE conduct in-plant and onsite inspections and audits using the DOE Building America Program and ENERGY STAR quality assurance protocols. It also was suggested that DOE's certification system “complement” the existing HUD system and that prospective DOE third-party certifiers receive adequate training to ensure that inspections would be conducted properly. Another commenter suggested that DOE rely on the EPA ENERGY STAR verification and labeling program to ensure compliance with the DOE energy conservation standards. One commenter suggested that DOE check the quality of construction while asserting that HUD should enforce violations of the DOE energy conservation standards. Furthermore, a commenter suggested that all manufactured homes be labeled using the DOE EnergySmart Home scale tool to demonstrate compliance with the proposed energy conservation standards. Finally, DOE received comments questioning the need for the development of energy conservation standards, noting the state of the housing market and the time and cost associated with the process to develop such requirements. Conversely, DOE received other comments indicating that more stringent energy conservation requirements are “urgently needed” to prevent lost opportunities for energy and operating cost savings that are not currently being captured. DOE also was asked to consider adopting various energy efficiency improvements contained in the 2010 version of NFPA Standard 501. DOE received further comments indicating that the manufactured housing industry is in the unique position to meet national energy conservation goals while preserving home affordability. One commenter stated that increases in the purchase price of manufactured homes due to energy conservation improvements could raise issues of affordability without government subsidies or incentives. Another commenter similarly stated that raising energy conservation standards too quickly could impact manufacturers' ability to modify their in-plant production and site-installation processes and procedures. Other commenters requested that DOE delay the effective date of any energy conservation requirements due to current economic conditions in order to give manufacturers sufficient time to meet the new energy conservation standards. Finally, commenters urged DOE to consult and collaborate with HUD, EPA, and the manufactured housing industry in development of the proposed rule. DOE notes that it is required by statute to set forth energy conservation standards for manufactured homes, and DOE carefully has considered comments regarding the scope of the proposed rule in developing the energy conservation requirements proposed herein. On June 25, 2013, DOE published a request for information (RFI) seeking information on indoor air quality, financing and related incentives, model systems of enforcement, and other studies and research relevant to DOE's effort to establish conservation standards for manufactured housing. (78 FR 37995) With regard to indoor air quality, one commenter mentioned that reductions in air leakage can lead to increased formaldehyde concentrations and noted that increased mechanical ventilation also can increase moisture infiltration in humid climates, potentially leading to deleterious impacts such as mold growth. Several other commenters noted that there have been no reported issues with occupant health in energy efficient homes that have been sealed tightly to reduce air infiltration. Moreover, commenters noted that a home that is equipped with proper mechanical ventilation, such as the mechanical ventilation level required by the HUD Code, is adequate to ensure indoor air quality. DOE is preparing the draft EA in parallel with this rulemaking, and it will be posted to the DOE Web site separately. This draft EA will discuss the relationship among indoor air quality, air leakage, and occupant health. Comments on financing focused on the affordability of manufactured housing and the potential impacts of the proposed rule on the ability of purchasers of manufactured homes to qualify for financing. Commenters noted that increased costs associated with more energy efficient homes could have a negative impact on affordability in an industry in which the majority of home purchasers are low-income individuals and families. DOE has designed the proposed standards to achieve greater energy conservation in manufactured housing while accounting for the costs and benefits of the proposed standards on manufactured homeowners. In this regard, DOE has analyzed the lifecycle costs to low-income purchasers of manufactured homes ( see chapter 9 of the TSD) and potential changes in manufactured home shipments in response to changes in purchase price ( see chapter 10 of the TSD). Commenters generally agreed that DOE should integrate a program of compliance and enforcement into the existing structure utilized by HUD. Commenters also noted, however, that DOE should maintain a role in overseeing enforcement of its standards. Although DOE is not considering compliance and enforcement in this proposed rule, DOE will consider these comments in a future rulemaking if appropriate. DOE received other comments and data, including information on the average term of a manufactured housing loan. Another commenter stated that DOE should establish requirements that achieve the greatest possible energy conservation in manufactured housing, as the benefits of potential energy savings would outweigh potential increased purchase prices. Another commenter suggested that DOE develop standards that match the IECC as closely as possible. Finally, a commenter suggested that DOE abandon its rulemaking effort and begin the process anew while a set of joint commenters urged DOE to expedite publishing of a proposed rule. DOE has considered these comments in its analysis and the development of this proposed rule. After reviewing the comments received in response both to the ANOPR and to the June 2013 RFI and other stakeholder input, DOE ultimately determined that development of proposed manufactured housing energy conservation standards would benefit from a negotiated rulemaking process. On June 13, 2014, DOE published a notice of intent to establish a negotiated rulemaking MH working group to discuss and, if possible, reach consensus on a proposed rule. See 79 FR 33873. On July 16, 2014, the MH working group was established under ASRAC in accordance with the Federal Advisory Committee Act and the Negotiated Rulemaking Act. See 79 FR 41456; 5 U.S.C. 561-70, App. 2. The MH working group consisted of representatives of interested stakeholders with a directive to consult, as appropriate, with a range of external experts on technical issues in development of a term sheet with recommendations on the proposed rule. The MH working group consisted of 22 members, including one member from ASRAC and one DOE representative. The MH working group met in person during six sets of public meetings held in 2014 on August 4-5, August 21-22, September 9-10, September 22-23, October 1-2, and October 23-24. See 79 FR 48097; 79 FR 59154. On October 31, 2014, the MH working group reached consensus on energy conservation standards in manufactured housing and assembled its recommendations for DOE into a term sheet that was presented to ASRAC. See public docket EERE-2009-BT-BC-0021-0107 (Term Sheet). ASRAC approved the term sheet during an open meeting on December 1, 2014, and sent it to the Secretary of Energy to develop a proposed rule. On February 11, 2015, DOE published an RFI (the 2015 RFI) requesting information that would aid in its determination of proposed SHGC requirements for certain climate zones. (80 FR 7550) One commenter indicated that DOE's negotiated rulemaking process was analytically flawed and made many procedural errors in carrying out the rulemaking process, including the operation of the MH working group and the interpretation of the underlying statutory directive on accounting for cost-effectiveness. This commenter also provided alternative cost data for use in the cost-benefit analysis. DOE has included a more detailed discussion of the comments received in response to the request for information in section III.B of this document. Following preparation and submission of the term sheet by the MH working group, DOE engaged in further consultation with HUD regarding DOE's proposed energy conservation standards. In addition to meeting with HUD, DOE prepared two presentations to discuss the proposed rule with the MHCC members, designed to gather information on the development of the proposed standards. DOE has considered all information ascertained from HUD, state agencies, the manufactured housing industry, and the public in developing the proposed rule. In an attempt to understand how certain requirements included in DOE's proposed rule would impact other aspects of the design and construction of manufactured homes, DOE also has carefully reviewed the HUD Code to ensure that the proposed rule would avoid unintended conflicts with HUD requirements both related and unrelated to energy conservation. The MH working group was established to negotiate energy conservation standards for manufactured housing and did not address options for systems of compliance and enforcement. DOE thus has not included proposed compliance and enforcement provisions in this document. DOE maintains its authority to address these issues in a future rulemaking. DOE also has not included proposed provisions related to waivers or exception relief that would be available to manufacturers in achieving compliance with this Part. Regarding waivers, DOE is interested in receiving information on whether a process is warranted by which a manufacturer could petition DOE for relief from an individual requirement. DOE also seeks public input on whether to establish proposed provisions for exception relief, which would be warranted in instances in which compliance with the proposed regulations would result in serious hardship, gross inequity, or unfair distribution of burdens on the part of a manufacturer. DOE may consider including proposed provisions in this regard in a future rulemaking. III. Discussion A. The Basis for the Proposed Standards EISA requires that DOE establish energy conservation standards for manufactured housing that are “based on the most recent version of the [IECC] . . . , except in cases in which [DOE] finds that the [IECC] is not cost-effective, or a more stringent standard would be more cost-effective, based on the impact of the [IECC] on the purchase price and on total life-cycle construction and operating costs.” See 42 U.S.C. 17071(b). Given that the 2015 edition of the IECC (the 2015 IECC) constitutes “the most recent version of the IECC,” the MH working group based its recommendations on the specifications included in the 2015 IECC that are appropriate for manufactured homes, which DOE has considered in developing the proposed rule. As noted above, the 2015 IECC applies generally to residential buildings, including site-built and modular housing, and is not specific to the manufactured housing industry. Consistent with the recommendations of the MH working group, DOE proposes standards that are based on certain specifications included in the 2015 IECC and that account for the unique aspects of manufactured housing. DOE carefully considered the following aspects of manufactured housing design and construction in developing the proposed standards: • Manufactured housing structural requirements contained in the HUD Code; • External dimensional limitations associated with transportation restrictions; • The need to optimize interior space within manufactured homes; and • Factory construction techniques that facilitate sealing the building thermal envelope to limit air leakage. Based on these considerations, and consistent with the recommendations of the MH working group, DOE is proposing certain requirements that differ from similar provisions contained in the 2015 IECC. These include presenting the building thermal envelope requirements in terms of U o of the entire building thermal envelope, accounting for space limitations in ceiling assemblies when establishing insulation requirements and other revisions to ensure the text is applicable to manufactured housing. Additionally, the MH working group recommended, and DOE considered, in developing this proposed rule the potential effects on purchase price and total lifecycle construction and operating costs, design and factory construction techniques unique to manufactured homes, and the impacts of reliance on the climate zones established by HUD and as set forth in the 2015 IECC. A detailed discussion of each of these issues is contained in chapter 8 of the TSD and sections III.B and III.C of this document. The following section discusses in detail the proposed energy conservation standards as set forth in the proposed rule. Subpart A as proposed contemplates the scope of the proposed standards, proposed definitions of key terms, and other commercial standards that would be incorporated by reference into this part. The subpart also proposes a compliance date of one year following the publication of the final rule. Proposed subpart B would include energy conservation requirements associated with the building thermal envelope of a manufactured home according to the climate zone in which the home is located. DOE proposes to base its building thermal envelope energy conservation standards on four climate zones, which generally follow state borders with some exceptions. DOE proposes two options to ensure an appropriate level of thermal transmittance through the building thermal envelope. The first approach contemplates prescriptive requirements for components of the building thermal envelope. The second is a performance-based approach under which a manufactured home would be required to achieve a maximum U o in addition to fenestration U -factor and SHGC requirements. Subpart B also would establish prescriptive requirements for insulation and sealing the building thermal envelope to limit air leakage. Subpart C would include requirements related to duct leakage; HVAC thermostats and controls; service water heating; mechanical ventilation fan efficacy; and equipment sizing. As noted in this preamble, EISA requires DOE to update its energy conservation standards for manufactured housing not later than one year after any revision to the IECC. Pursuant to this statutory direction, DOE intends to update its energy conservation standards for manufactured housing, if promulgated, within one year of the publication of any revision to the 2015 IECC. This proposed rule invites comments on all DOE proposals and issues presented herein, and requests comments, data, and other information that would assist DOE in developing a final rule. B. Proposed Energy Conservation Requirements 1. Subpart A: General (a) § 460.1 Scope Pursuant to section 413 of EISA, Congress directed DOE to establish standards for energy conservation in manufactured housing. Section 460.1 would restate the statutory requirement and introduce the scope of the proposed requirements. Section 460.1 also would require manufactured homes that are manufactured on or after one year following publication of the final rule to comply with the requirements established in part 460. DOE proposes a one-year period following publication of a final rule to allow manufacturers to transition their designs, materials, and factory operations and processes to comply with the finalized DOE energy conservation standards and regulations. A one-year notice period is common industry practice for amendments to the IECC and other changes to building codes; however, DOE seeks input on whether these standards are analogous to IECC or whether they would impose a different level of manufacturer research and effort to comply. In addition, DOE seeks comment on whether additional lead time is necessary to harmonize compliance and enforcement with HUD's manufactured housing program, redesign manufactured housing to meet the standards, and test and certify the new designs. The agency also requests comment on whether there are any particular timing considerations that the agency should consider due to manufacturers choosing to comply with either the prescriptive or thermal envelope compliance paths. DOE requests comment on the scope and effective date of the proposed rule and whether the proposed effective date would provide manufacturers sufficient lead time to prepare to comply with the standards. (b) § 460.2 Definitions Section 460.2 would define key terms used throughout the proposed regulations, many of which were derived from either the 2015 IECC or the HUD Code, with modifications where further clarification was needed in the context of manufactured housing. Proposed definitions based on terms included in the 2015 IECC were developed in accordance with recommendations from the MH working group. See Term Sheet at 1. DOE has included a discussion of each of the proposed definitions in the following paragraphs. (a) Accessible. DOE proposes to adopt the definition of the term “accessible” from the 2015 IECC while clarifying that the definition would allow access to certain labels or control interfaces that require close approach upon inspection or repair. (b) Air barrier. The term “air barrier” also would be based on the definition of the same term in the 2015 IECC while clarifying that an air barrier could consist of a single material or combination of materials. DOE intends for the definition of this term to include the materials involved in limiting air leakage to meet air sealing requirements and requests comment on whether further clarification is needed on the meaning in this regard. (c) Automatic. DOE proposes to adopt the definition of the term “automatic” from the 2015 IECC. The terms “automatic” and “manual” would differentiate between controls that are operated by impersonal (automatic) and personal (manual) influences. (d) Building thermal envelope. DOE has derived the proposed definition of “building thermal envelope” from the definition of the same term in the 2015 IECC, with revisions that account for the manner in which manufactured homes are designed and constructed. The proposed definition does not include basement walls, for example, given the unique construction of a manufactured home relative to a site-built home. (e) Ceiling. DOE proposes to define the term “ceiling,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed prescriptive standards of part 460. (f) Circulating hot water system. DOE would define the term “circulating hot water system” to be consistent with the 2015 IECC to describe water distribution systems in a manufactured home that uses a pump to circulate water between water-heating equipment and fixtures. (g) Climate zone. DOE proposes to define the term “climate zone” in accordance with the term as defined in the 2015 IECC, with revisions as applicable to the specific geographic regions set forth in the proposed rule. The proposed rule establishes different energy conservation standards for manufactured homes located in different climate zones. (h) Conditioned space. DOE would adopt the definition of the term “conditioned space” from the 2015 IECC to describe areas, rooms, or spaces that are enclosed within the building envelope. (i) Continuous air barrier. DOE proposes to adopt the definition of the term “continuous air barrier” from the 2015 IECC to encompass the material or combination of materials that limit air leakage through the building thermal envelope. (j) Door. DOE would define the term “door,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed prescriptive standards of part 460. (k) Dropped ceiling. DOE proposes to define the term “dropped ceiling,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed standards under §§ 460.103(a) and 460.104. (l) Dropped soffit. DOE would define the term “dropped soffit,” which also is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed prescriptive standards under §§ 460.104(a) and 460.104. (m) Duct. DOE proposes to adopt the definition of the term “duct” from the 2015 IECC to include tubes or conduits, except air passages within a self-contained system, used for conveying air to or from heating, cooling, or venting equipment. (n) Duct system. DOE proposes to define the term “duct system” as derived from the meaning of the term under the 2015 IECC to refer to a continuous passageway for the transmission of air, composed of ducts and other required accessories. (o) Eave. DOE would define the term “eave,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed prescriptive standards under §§ 460.103(a) and 460.104. (p) Equipment. DOE proposes to define the term “equipment,” which is not defined in the 2015 IECC or the HUD Code, to add further clarification to the meaning of the proposed prescriptive provisions of this part. (q) Exterior wall. DOE proposes to adopt the definition of the term “exterior wall” from the 2015 IECC and describes walls that enclose conditioned space. (r) Fenestration. DOE would derive the definition of the term “fenestration” from the 2015 IECC, which encompasses both vertical fenestration and skylights. DOE requests comment on whether to amend the definition of “fenestration” to include tubular daylighting devices. (s) Floor. DOE proposes to define the term “floor,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed prescriptive standards of part 460. (t) Glazed or glazing. DOE would define the terms “glazed” or “glazing,” which are not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed prescriptive standards of this Part and for consistency with the meaning of the terms as used in the National Fenestration Rating Council Standard 100-2004. (u) Infiltration. DOE proposes to adopt the definition of the term “infiltration” from the 2015 IECC, which describes the uncontrolled air leakage into a manufactured home. (v) Insulation. DOE would define the term “insulation” to mean material qualifying as “insulation” for consistency with the U.S. Federal Trade Commission definition of insulation and to ensure specificity with the proposed standards of part 460. (w) Manufactured home. DOE proposes to adopt the same definition of “manufactured home” as used in the HUD Code in order to ensure consistency among both agencies' regulations. (x) Manufacturer. As discussed below, the underlying statutory authority for this rulemaking does not define the term “manufacturer.” DOE proposes to adopt the definition of the term under the HUD Code to mean any person engaged in the factory construction or assembly of a manufactured home, including any person engaged in import of a manufactured home for resale. (y) Manual. DOE proposes to define the term “manual” to be consistent with the 2015 IECC. As stated in this preamble, the terms “automatic” and “manual” would differentiate between controls that are operated by impersonal (automatic) and personal (manual) influences. (z) R -value (thermal resistance). DOE would adopt the definition of the term “ R -value” from the 2015 IECC to refer to a defined quantitative measure of the resistance to heat flow of a material or assembly of materials. (A) Rough opening. The term “rough opening,” which is not defined in the 2015 IECC or the HUD Code, would identify the location corresponding to the area of an assembly containing fenestration. (B) Service hot water. DOE proposes to adopt the definition of the term “service hot water” from the 2015 IECC to refer to the supply of hot water for uses other than space or comfort heating, such as for bathing. (C) Skylight. DOE proposes to define the term “skylight” based on the meaning of the term in the 2015 IECC, clarifying that the term includes the entire assembly of glass or other transparent or translucent glazing material and the frame, installed at a slope of less than 60 degrees from the horizontal. (D) Solar heat gain coefficient (SHGC). DOE would adopt the definition of the term “solar heat gain coefficient” from the 2015 IECC. SHGC is an important property of transparent or translucent fenestration that affects the heat gain and loss of the building thermal envelope. The SHGC of a fenestration assembly is defined as the ratio of the amount of solar heat gain transmitted or reradiated through the assembly to the amount of incident solar radiation. (E) State. The term “state” would include each of the 50 states, the District of Columbia, the Commonwealth of Puerto Rico, Guam, the U.S. Virgin Islands, and American Samoa. (F) Thermostat. DOE proposes to adopt the definition of the term “thermostat” from the 2015 IECC to describe automatic control devices used to maintain a given temperature. (G) U -factor (thermal transmittance). DOE would adopt the definition of the term “ U -factor” from the 2015 IECC to refer to a defined quantitative measure of the transmittance of heat of a material or assembly of materials. (H) U o (overall thermal transmittance). DOE proposes to define the term U o (overall thermal transmittance), which is not defined in the 2015 IECC or HUD Code, as the coefficient of heat transmission (air to air) through the entire building thermal envelope, equal to the time rate of heat flow per unit area and unit temperature difference between the warm side and cold side air films. (I) Ventilation. DOE proposes to adopt the definition of the term “ventilation” from the 2015 IECC to refer to the supply or removal of air from any space by natural or mechanical means. (J) Vertical fenestration. DOE would adopt the definition of the term “vertical fenestration” from the 2015 IECC to include materials, such as windows and doors that may be glazed or opaque, installed at an angle of greater than or equal to 60 degrees from horizontal. (K) Wall. DOE proposes to define the term “wall,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed standards under this Part. (L) Whole-house mechanical ventilation system. DOE proposes to adopt the definition of the term “whole-house mechanical ventilation system” from the 2015 IECC to refer to a mechanical system that is designed to exchange indoor air with outdoor air either periodically or continuously. (M) Window. DOE proposes to define the term “window,” which is not defined in the 2015 IECC or the HUD Code, to ensure specificity with the proposed standards under this part. (N) Zone. DOE would adopt the definition of the term “zone” from the 2015 IECC to apply to controls within a manufactured home and to refer to a space or group of spaces within a manufactured home with sufficiently similar requirements for heating and cooling that can be maintained using a single controlling device. DOE would not include certain definitions that are contemplated in the 2015 IECC, including “above-grade wall,” “addition,” “alteration,” “approved,” “approved agency,” “basement wall,” “building,” “building site,” “C-factor,” “code official,” “commercial building,” “conditioned floor area,” “continuous insulation,” “curtain wall,” “demand recirculation water,” “DOE,” “energy analysis,” “energy cost,” “energy simulation tool,” “energy rating index (ERI) reference design,” “fenestration product,” “site-built,” “F-factor,” “heated slab,” “high-efficacy lamps,” “historic building,” “insulating sheathing,” “insulated siding,” “labeled,” “listed,” “low-voltage lighting,” “proposed design,” “rated design,” “readily accessible,” “repair,” “reroofing,” “residential building,” “roof assembly,” “roof recover,” “roof repair,” “roof replacement,” “standard reference design,” “sunroom,” “thermal envelope,” “thermal isolation,” “ventilation air,” and “visible transmittance.” These terms are either not relevant to manufactured housing or not relevant to the energy conservation requirements proposed in this subpart. DOE requests comment on each of the proposed definitions and seeks input on the need for additional clarification to ensure consistency among the HUD Code and general industry practice. (c) § 460.3 Materials Incorporated by Reference DOE proposes to incorporate certain materials by reference in the proposed rule, including Air Conditioning Contractors of America (ACCA) Manual J; ACCA Manual S; and “Overall U -Values and Heating/Cooling Loads—Manufactured Homes” by Conner and Taylor (the Battelle Method). ACCA Manuals J and S would be incorporated by reference in accordance with § 460.205 of this subpart and would relate to the selection and sizing of heating and cooling equipment. The Battelle Method is an industry standard methodology for calculating the overall thermal transmittance of a manufactured home. The Battelle method currently is referenced in the HUD Code for calculation of overall thermal transmittance. To maintain consistency with the practices of the manufactured home industry, DOE has determined these materials are appropriate for inclusion in the proposed rule. 2. Subpart B: Building Thermal Envelope DOE proposes to establish energy conservation standards for manufactured housing based on the size and geographic location of a home, as doing so would allow DOE to capture a more accurate balance between energy conservation and cost-effectiveness in developing its standards. For example, manufactured homes frequently are identified by size, including single-section and multi-section homes. Manufactured homes of varying size are capable of reaching different levels of energy conservation based on the ratio of floor square footage to building thermal envelope surface area. A single energy conservation standard for manufactured homes of all sizes thus would be more difficult to achieve in a single-section homes as compared to a multi-section home. Consistent with the recommendations of the MH working group, DOE proposes to establish different standards for manufactured homes located in different regions of the country and for manufactured homes of different size. Subpart B reflects DOE's proposed approach in this regard, and DOE requests comment in this regard. (a) § 460.101 Climate Zones Pursuant to EISA, DOE may consider basing its energy conservation standards on the climate zones established by HUD rather than on the climate zones contained in the IECC. See 42 U.S.C. 17071(b)(2)(B). The potential for climatic differences to affect energy consumption supports an approach in which energy conservation standards account for geographic differences in climate. For example, the appropriate level of insulation for a manufactured home located in southern Florida would not necessarily be appropriate for a manufactured home located in New Hampshire. As indicated in Figure III.1, the HUD Code divides the United States into three distinct climate zones for the purpose of setting its building thermal envelope requirements, the boundaries of which are separated along state lines. Conversely, as indicated in Figure III.2, section R301.1 of the 2015 IECC divides the country into eight climate zones, the boundaries of which are separated along county lines. The 2015 IECC also provides requirements for three possible variants (dry, moist, and marine) within certain climate zones, as indicated in Figure III.2. The HUD Code climate zones were developed to be sensitive to the manner in which the manufactured housing industry constructed and placed manufactured homes into the market. The 2015 IECC climate zones are separated along county lines to reflect a more accurate overview of climate distinctions within the United States and to facilitate state and local enforcement of the IECC for residential and commercial buildings, including site-built and modular construction. EP17JN16.001 The 2015 IECC includes climate zone-specific prescriptive energy conservation specifications for the building thermal envelope. In accounting for the design and factory construction techniques for manufactured homes, the MH working group recommended that DOE perform a LCC analysis on various cities located in each of the 2015 IECC climate zones. The MH working group also recommended that DOE incorporate into its LCC analysis several alternatives to certain 2015 IECC prescriptive specifications, including alternative levels of insulation in ceilings, walls, and floors. DOE calculated the LCC for various alternatives to the 2015 IECC prescriptive specifications for 19 cities, representing a geographically diverse set of climates, with at least one city in each of the 2015 IECC climate zones. As discussed in greater detail in section III.B.2.b of this document and chapters 6 and 8 of the TSD, DOE's LCC analysis demonstrated that common building thermal envelope requirements for multiple groups of cities proved to be most cost-effective. After reviewing DOE's LCC analysis, the MH working group recommended that DOE establish four climate zones that placed cities with the same set of most-cost-effective building thermal envelope requirements in the same climate zone. The MH working group found that a four climate zone approach would improve upon the HUD Code climate zones with regard to energy conservation by more accurately distinguishing among regions with similar climates while simultaneously minimizing the extensive subdivisions of states found in the 2015 IECC. Consistent with the recommendations of the MH working group 4 and as illustrated in Figure III.3, § 460.101 would establish a new climate zone arrangement that reflects the advantages of both the HUD Code and the 2015 IECC climate zones. See Term Sheet at 2. 4 The term sheet named the four climate zones 1A, 1B, 2, and 3. DOE proposes to rename these climate zones as 1 (former climate zone 1A), 2, (former climate zone 1B), 3 (former climate zone 2), and 4 (former climate zone 3). EP17JN16.002 If DOE's proposed energy conservation standards adopted the eight climate zones established in the 2015 IECC, 40 states would be divided into two or more climate zones. Although the 2015 IECC climate zones more precisely account for climatic conditions that affect energy use in the United States, any loss of accuracy in addressing climatic differences is negligible compared to the impracticality to the manufactured housing industry of designing and constructing manufactured homes that comply with eight different sets of climate zone requirements and planning home shipments based on individual states with multiple climate zones. A large number of climate zones, particularly within a state, would burden the manufactured housing industry because manufacturers are not always certain of the eventual destination of a home during the manufacturing process. That is, although some manufactured homes are custom orders where the destination is known prior to manufacture, many other manufactured homes are stocked as inventory with manufactured housing dealers. In particular, manufactured housing dealers and installers in states with multiple climate zones would encounter increased complexities associated with ordering, stocking, selling, installing, and servicing manufactured homes. Although DOE generally prioritized establishment of a single climate zone per state where appropriate, the size or varied climate of certain states necessitated two climate zones in some instances. DOE's proposed climate zones bifurcate Texas, Louisiana, Alabama, Mississippi, Georgia, and Arizona. Data indicates that the inland climate of Texas, Louisiana, Alabama, Mississippi, and Georgia varies significantly from these states' coastal climates along the borders of the Gulf of Mexico. Similarly, southwestern Arizona exhibits different weather patterns from the rest of the state. DOE requests comment on the proposal to establish four climate zones as well as input with regard to categorization of states and counties that comprise each climate zone. To the extent that a particular approach is advocated, commenters also should provide analyses and data on the potential impact to the costs and benefits of the proposed rule. DOE also requests comment on the need for additional training of state and local building officials who must be familiar with the requirements of two rather than one climate zone. (b) § 460.102 Building Thermal Envelope Requirements Section 460.102 would establish requirements related to the building thermal envelope, which includes the materials within a manufactured home that separate the interior conditioned space from the exterior of the building or interior spaces that are not conditioned space. As discussed in this preamble, § 460.102(a) would establish two approaches to ensure that the building thermal envelope would meet more stringent energy conservation levels: A prescriptive option and a maximum U o option. In developing recommendations under this section, the MH working group carefully considered section R402.1 of the 2015 IECC, which sets forth two primary compliance pathways. First, sections R402.1.2 and R402.1.4 of the 2015 IECC contain climate zone-specific prescriptive building thermal envelope component R -value requirements, prescriptive fenestration U -factor requirements, and prescriptive SHGC requirements. Second, section R402.1.5 of the 2015 IECC provides an alternate pathway to compliance, which allows for a home to be constructed using a variety of materials as long as the entire building thermal envelope has a singular total UA value 5 that is less than or equal to the sum of the component U -factor requirements under section R402.1.4 multiplied by the surface area of the building thermal envelope components. The first option is referred to as a “prescriptive-based approach” and the second option is referred to as a “performance-based approach.” 5 Total UA is a metric that is very similar to U o that typically is used in the context of site-built construction. Section R402.1.5 of the 2015 IECC uses the metric “total UA, ” which denotes the sum of each building thermal envelope component's U -factor multiplied by the assembly area of the component. This metric is referred to as “ U o ” in the manufactured housing industry and serves the same function as “total UA. ” DOE considered developing proposed requirements in line with either a prescriptive-based approach or a performance-based approach for specific assemblies that comprise the building thermal envelope. Ultimately, however, and consistent with the recommendation of the MH working group, DOE determined that allowing manufacturers to choose between two pathways for compliance would realize cost-effective energy savings for homeowners while providing for flexibility within the manufactured housing industry. See Term Sheet at 3-4. The prescriptive approach would establish specific component R -value, U -factor, and SHGC requirements, providing a straightforward option for construction planning. This pathway would facilitate the ease of compliance but would restrict manufacturer flexibility in making trade-offs, such as increasing insulation levels in some building thermal envelope components while decreasing insulation levels in other building thermal envelope components. In contrast, the performance-based approach would allow a manufactured home to be constructed using a variety of different materials with varying thermal properties so long as the building thermal envelope achieved a required level of overall thermal performance. The performance-based approach thus would provide manufacturers with greater flexibility in identifying and implementing cost-effective approaches to building thermal envelope design. The performance-based approach is familiar to the manufactured housing industry, as this approach is the basis for the building thermal envelope requirements under the HUD Code. The proposed performance-based requirements would be intended to be functionally equivalent to the prescriptive-based requirements in that both options would result in manufactured homes with approximately the same amount of energy use. DOE requests comment on the proposal to set forth prescriptive and performance options for the purpose of compliance with the proposed building thermal envelope requirements. In particular, DOE requests comment on the requirements of each pathway as well as their equivalency in terms of overall thermal performance. The proposed prescriptive building thermal envelope requirements under § 460.102(b) are stated in terms of minimum R -value and maximum U -factor and SHGC requirements. The MH working group recommended the prescriptive values set forth in Table III.3 that DOE has adopted in this rulemaking by assessing and revising the 2015 IECC specifications to ensure cost-effectiveness based on the impact on the purchase price of manufactured homes and on total lifecycle construction and operating costs. See Term Sheet at 3. Table III.1—Proposed Building Thermal Envelope Prescriptive Requirements Climate zone Ceiling R -value Wall R -value Floor R -value Window U -factor Skylight U -factor Door U -factor Glazed fenestration SHGC 1 30 13 13 0.35 0.75 0.40 0.25. 2 30 13 13 0.35 0.75 0.40 0.33. 3 30 21 19 0.35 0.55 0.40 0.33. 4 38 21 30 0.32 0.55 0.40 No Rating. As discussed in greater detail in chapter 6 of the TSD, DOE developed the requirements included in § 460.102(b), as illustrated in Table III.1, by evaluating the cost-effectiveness of the 2015 IECC building thermal envelope specifications and alternatives to these specifications. DOE performed LCC analysis for all alternatives to the 2015 IECC specifications that were recommended by the MH working group, in order to assist in the development of cost-effective standards under this rule. The MH working group requested that DOE evaluate variations in the R -value requirement for ceilings, walls, and floors, and the U -factor requirement for windows, to determine the impact on cost-effectiveness relative to the 2015 IECC requirements. Upon analyzing a range of ceiling insulation requirements from R -22 to R -38, wall insulation requirements from R -13 to R -21, floor insulation requirements from R -13 to R -38, and window U-factor requirements from 0.40 to 0.31, DOE has proposed the most cost-effective energy conservation requirement for each climate zone, as included in Table III.1. The MH working group also requested that DOE conduct sensitivity analyses of window SHGC. See Term Sheet at 3. In climate zone 1, DOE analyzed a range of window SHGC from 0.25 to 0.40. DOE is proposing the most cost-effective SHGC requirement for climate zone 1, as included in Table III.1. In climate zone 4, the MH working group requested that DOE not run sensitivity analyses for different SHGC options for most cities found in climate zone 4. SHGC has a smaller impact on energy use in regions dominated by heating rather than cooling loads. In these locations, more stringent SHGC requirements can lead to increased energy consumption by blocking the solar heating effects of sunlight. For these reasons, the MH working group proposed to not modify the 2015 IECC specification of no requirement, and DOE is incorporating the 2015 IECC specification of no SHGC requirement for proposed climate zone 4. Please see chapter 6 of the TSD for additional detail on DOE's SHGC sensitivity analyses. The MH working group also recommended that DOE perform a sensitivity analysis of the total cost of ownership to determine the most cost-effective SHGC for climate zones 2 and 3. See Term Sheet at 3. DOE recognizes that many variables affecting the selection of recommended SHGC values were discussed by the MH working group over the course of multiple public meetings. At the recommendation of the MH working group, DOE studied the potential economic impacts of several SHGC values with the intent of proposing prescriptive SHGC requirements that provide the greatest economic benefit. Economic impact was the primary decision tool used in proposing prescriptive SHGC values, and DOE has prepared an economic analysis that supports different SHGC requirements for climate zones 2 and 3. DOE specifically found that an SHGC of 0.30 was the most cost-effective SHGC value based on a 10-year cost of ownership savings calculation. See 80 FR 7550. In arriving at this value, DOE placed all windows on one side of the manufactured home, with the windows facing west. DOE used this window orientation in its sensitivity analysis in order to arrive at SHGC values that would have the greatest impact on energy savings. DOE sought public input on this methodology and analysis in the 2015 RFI. See 80 FR 7550. In response to the 2015 RFI, several commenters stated that factors other than total cost of ownership should be considered when proposing a prescriptive SHGC requirement. One commenter suggested that the total cost of ownership analysis should not be the sole consideration for choosing the SHGC requirement and that DOE should consider the 2015 IECC SHGC specifications, lifecycle costs, potential impacts on the purchase price of manufactured housing, air conditioner down-sizing and cost savings opportunities, reductions in peak electric loads, and manufacturer benefits in harmonizing SHGC across climate zones. Another commenter suggested that equipment downsizing, reduction in peak demand, improved occupant comfort leading to behavioral changes in adjusting a thermostat, synchronizing with the 2015 IECC, and lifecycle costs should be considered as a basis for the proposed SHGC requirements. The commenter also recommended that an SHGC of 0.25 in climate zones 1, 2, and 3 would be beneficial, as doing so would establish only two window requirements (SHGC of 0.25 in climate zones 1, 2, and 3; and no SHGC requirement for climate zone 4) and would simplify and streamline the purchasing of windows for manufacturers of manufactured homes. Other commenters noted that placing all windows on one side of a manufactured home with the assumption that all windows face west was an atypical assumption. The commenters suggested that window orientation should follow the same “industry average” convention used in all other assumptions used in DOE's SHGC analysis. The commenters presented analysis based on their assessment of industry averages to demonstrate that such assumptions would support an SHGC requirement of 0.33; however, this analysis included assumptions that differed from those agreed upon by the MH working group, including window-to-floor area, window shading, and window cost. The commenters also noted that a group of windows with a weighted SHGC of 0.30 would require a mixture of window products of dissimilar aesthetic. Finally, the commenters believed that the likely industry response to a 0.30 SHGC requirement would be to assemble manufactured homes with a single window product SHGC value closer to 0.25. DOE also received a comment that supported the window orientation that DOE employed in its analysis, recommending that the analysis properly based SHGC assumptions on window orientation that would experience the highest energy use. In response to the aforementioned comments, DOE determined that the window orientation assumption used in its SHGC analysis was inconsistent with other analytical assumptions under the proposed rule, as a more representative SHGC analysis would place windows uniformly on all sides of a manufactured home. Although the assumption of all windows facing west represents the highest energy use window orientation, manufactured homes with other window orientations would not experience as large an economic benefit. DOE also found no reason to deviate from the other assumptions in the submitted analysis (window-to-floor area, window shading, and window cost) that formed the basis of the MH working group's deliberations and recommendations. Finally, DOE notes that factors such as lifecycle costs, potential impacts on the purchase price of manufactured housing are included in its analysis. DOE did not include air conditioner down-sizing and cost savings opportunities in its SHGC analysis. Although in some instances a manufacturer may be able to install a smaller air conditioner, for example, leading to reduced energy costs and a lower purchase price, this is not always possible. DOE did not prioritize peak electric load reduction over lifecycle cost savings to individual manufactured homeowners under its analysis. Finally, while equivalent SHGC requirements across climate zones could simplify window procurement for manufacturers, DOE notes that manufacturers could elect to use the same window types for manufactured homes shipped to any climate zone in accordance with the proposed rule. DOE repeated its SHGC sensitivity analysis of climate zones 2 and 3 using a uniform window orientation to study the economic impacts of SHGC values of 0.25, 0.30, and 0.33. This analysis indicated SHGC of 0.33 had the greatest total cost of ownership savings; therefore, DOE proposes requiring SHGC of 0.33 in climate zones 2 and 3. Because the sensitivity analysis performed for climate zone 1 during the negotiated consensus process used the original assumption of uniform window distribution, this analysis was not repeated for climate zone 1. For skylight U -factor requirements, the MH working group did not request that DOE evaluate the effect of variations of the 2015 IECC requirements on cost-effectiveness. Because there were LCC savings associated with the 2015 IECC requirements, DOE is proposing to adopt the 2015 IECC U -factor requirements for skylights into the proposed rule. This proposal is consistent with the recommendation of the MH working group. See Term Sheet at 3. For door U -factor requirements, DOE found that a manufactured home with a U -factor of 0.40 was cost-effective. Therefore, DOE proposes a prescriptive door U -factor requirement of 0.40 in all climate zones for the proposed rule. This proposal is consistent with the recommendation of the MH working group. See Term Sheet at 3. Section 460.102(b)(2) as proposed would require the truss heel height to be a minimum of 5.5 inches at the outside face of each exterior wall for the purpose of compliance with the prescriptive ceiling insulation R -value requirement established under § 460.102(b)(1). This minimum heel height requirement would ensure that a minimum space is available in the eaves of the ceiling, allowing for adequate insulation coverage near the eaves. This proposal is also consistent with the recommendation of the MH working group. See Term Sheet at 3. Section 460.102(b)(3) would authorize manufacturers to install ceiling insulation with either a uniform thickness or a uniform density. In many cases, a ceiling may need to be filled with loose blown insulation to a greater height at the center of the ceiling relative to the edges near the eaves to meet average overall R -value requirements. Although uniform insulation thickness is not required under the proposed standard, the 5.5-inch minimum truss heel height encourages a minimum insulation thickness at the eaves. This proposal is also consistent with the recommendations of the MH working group. See Term Sheet at 3. Section 460.102(b)(4) would authorize manufacturers to use a combination of R -21 batt insulation and R -14 blanket insulation in lieu of R -30 insulation for the purpose of compliance with the climate zone 4 floor insulation R -value requirement under paragraph (b)(1) of this section. This requirement would reflect industry practice in which manufactured homes often do not have space in the floor to accommodate R -30 insulation without compression. DOE thus proposes that R -21 batt insulation plus R -14 blanket insulation would be deemed compliant with the R -30 requirement in order to provide a prescriptive alternative for space-constrained floors. This proposal is also consistent with the recommendation of the MH working group. See Term Sheet at 3. Section 460.102(b)(5) would authorize manufacturers to exclude from the SHGC requirements under § 460.102(a) any individual skylight with an SHGC that is less than or equal to 0.30. This requirement effectively would establish an exception for skylights to the SHGC requirements in climate zone 1, setting forth a maximum skylight SHGC requirement of 0.30. This exception is set forth in the 2015 IECC in footnote “b” to Table R402.1.2. The MH working group recommended that DOE retain this requirement, and DOE agrees with including this exception in the proposed rule. See Term Sheet at 3. DOE also considered the potential impact of adopting sections R402.3.3 and R402.3.4 of the 2015 IECC in this rulemaking. Section R402.3.3 specifies that 15 square feet of glazed fenestration may be exempt from SHGC and U -factor requirements. DOE proposes not to adopt this requirement because the prescriptive fenestration SHGC and U -factor requirements would apply to all fenestration. Given that 15 square feet represents a large portion of the overall fenestration area that comprises a manufactured home, adoption of this requirement potentially would exclude from these requirements a significant source of energy conservation. Section R402.3.4 of the 2015 IECC exempts one side-hinged opaque door of up to 24 square feet in surface area from the 2015 IECC U -factor requirements. DOE has not adopted section R402.3.4 of the 2015 IECC, as excluding these types of doors from this proposed rulemaking also would represent the loss of a significant source of home energy conservation. Section R402.5 of the 2015 IECC specifies maximum U -factor requirements for sunroom fenestration. Because sunrooms are not commonly offered in manufactured housing, DOE determined this section was not applicable to manufactured housing and proposes not to include sunroom fenestration requirements in this proposed rule. Section 460.102(b)(6) would establish maximum U -factor values as alternatives to the minimum R -value requirements established under § 460.102(a). See Term Sheet at 5. DOE determined each proposed U -factor alternative by calculating the U -factor corresponding to a building component ( e.g., wall) with typical dimensions and construction using the insulation material R -value specified in Table III.1. More detail on establishing the proposed U -factor alternatives is provided in chapter 7 of the TSD. DOE notes that the proposed U -factor alternatives are based on a representative single-section manufactured home, which are an average of 4.2 percent higher than the corresponding calculations of U -factor alternatives using the dimensions of a representative multi-section manufactured home. DOE requests comment on the U -factor alternatives and their equivalency with the R -value requirements for ceiling, wall, and floor insulation. Specifically, DOE invites comment on the use of U -factor alternatives for ceiling insulation based on a conversion calculation using a representative single-section manufactured home. Section 460.102(b)(7) would establish a maximum ratio of 12 percent for glazed fenestration area to floor area. As discussed in further detail in chapter 7 of the TSD, DOE used this ratio as a typical housing characteristic in its analyses for determining the prescriptive requirements. Manufactured homes with window to floor area greater than 12 percent would use more energy (all else held equal), because glazed fenestration generally has a greater U -factor than other building components (such as walls). Although this requirement limits the amount of glazed fenestration in a manufactured home when a manufacturer is using the prescriptive requirements for compliance with the proposed rule, a manufacturer may instead follow the performance-based requirements for compliance if they wish to increase the area of glazed fenestration (in exchange for increasing the performance of other building thermal envelope components). The proposed performance-based requirements under § 460.102(c) are stated in terms of maximum U o of the entire building thermal envelope as a function of climate zone. The U o requirements proposed in § 460.102(c) were determined by applying the proposed prescriptive building thermal envelope requirements under § 460.102(b) to manufactured homes using typical dimensions and construction techniques and then calculating the resultant U o . See chapter 7 of the TSD for more detailed information on the typical dimensions of manufactured homes and the Battelle Method for more detailed information on the calculation of U o . As discussed in chapter 7 of the TSD, the proposed maximum U o for a multi-section manufactured home was calculated by assuming a 1,568-square-foot double-section manufactured home. The proposed maximum U o for a single-section manufactured home was calculated by assuming a 924-square-foot single-section manufactured home. Both multi- and single-section home U o values were calculated assuming manufactured homes built with wood framing and a window area equal to 12 percent of the floor area. DOE's proposed approach to determining U o is consistent with HUD's approach to determining U o under the HUD Code ( see 24 CFR 3280.507(a)), and is very similar to the ICC's approach to determining total UA under section R402.1.5 of the 2015 IECC. DOE believes that its approach to determining U o would reduce the compliance burden on manufacturers by avoiding the need for manufacturers to perform two separate calculations under both the HUD Code and the DOE requirements. Section R402.5 of the 2015 IECC includes specifications for maximum allowable fenestration U -factors when following the performance-based approach. The 2015 IECC specifies a maximum area-weighted average U -factor of 0.48 in IECC climate zones 4 and 5 for vertical fenestration, a maximum area-weighted average U -factor of 0.40 for IECC climate zones 6 through 8 for vertical fenestration, and a maximum area-weighted average U -factor of 0.75 for skylights in IECC climate zones 4 through 8. Consistent with the recommendations of the MH working group ( see Term Sheet at 1), DOE proposes to adopt these requirements under §§ 460.102(c)(2) and 460.102(c)(3) by limiting area-weighted vertical fenestration U -factor to 0.48 in climate zone 3, limiting area-weighted vertical fenestration U -factor to 0.40 in climate zone 4, and limiting area-weighted skylight U -factor to 0.75 in climate zones 3 and 4. Sections 460.102(c)(2) and 460.102(c)(3) would serve the purpose of limiting the extent to which window performance can be traded off for improved performance in other components of a manufactured home and would prevent areas of a manufactured home that are located in close proximity to vertical fenestration and skylights from being subject to excessive rates of heat loss. Finally, § 460.102(c)(4) would require windows, skylights, and doors containing more than 50 percent glazing by area to satisfy the SHGC requirements under § 460.102(a) on the basis of an area-weighted average and seeks to ensure flexibility among manufacturers that choose to use unique glazed fenestration products that otherwise would not meet the SHGC requirement individually. This proposal is also consistent with the recommendations of the MH working group. See Term Sheet at 4. DOE invites comment on proposal to include an area-weighted average calculation of SHGC for compliance with § 460.102(c). DOE also requests comment on all other prescriptive and performance requirements proposed in this section. To the extent that a commenter supports the proposed requirements or suggests alternative building thermal envelope criteria, DOE is specifically interested in data and calculations that would support the commenter's position. Section 460.102(d) would establish procedures for ensuring compliance with the prescriptive building thermal envelope standards under § 460.102(b). As discussed in this preamble, however, the MH working group did not address options for systems of compliance and enforcement, and DOE has not included proposed compliance and enforcement provisions in rule. In the event that DOE addresses compliance assurance in a future rulemaking, paragraphs (d)(1), (d)(2), (d)(4), (d)(5), and (d)(7) would be reserved to provide a methodology for calculating the R -value of insulation; the R -value of non-insulating materials; fenestration U -factor; the U -factor of walls, ceilings, and floors; and glazed fenestration SHGC that would provide for an accurate and repeatable procedure to determine compliance with the standards proposed under § 460.102(b). Section 460.102(d)(3) would establish that the total R -value of a component is the sum of the R -values of each layer of insulation that compose the component. This proposed requirement is consistent with section R402.1.3 of the 2015 IECC, which specifies that component insulation materials installed in layers has a total R -value equal to the sum of the R -values of each layer. Sections 460.102(d)(6) and 460.102(d)(8) would authorize manufacturers to determine U -factor or SHGC for certain fenestration products and doors in accordance with the prescriptive default values set forth in Tables 460.102-4, 460.102-5, and 460.102-6. DOE anticipates that a manufacturer could rely on these prescriptive default U -factor values to facilitate the ease of compliance with this proposed rule. DOE has designed proposed § 460.102(d)(6) for consistency with Tables R303.1.3(1), R303.1.3(2), and R303.1.3(3) of the 2015 IECC and in accordance with the MH working group's recommendations. DOE has proposed conservative prescriptive default values to provide an incentive to manufacturers to determine the actual performance value of the windows, doors, or skylights installed in a manufactured home. DOE expects the default tables would be used primarily in instances in which the actual performance value of a window, door, or skylight is unavailable or unknown. Section 460.102(e) would establish procedures for ensuring compliance with the building thermal envelope U o standards under § 460.102(c). As discussed in this preamble, the MH working group did not address options for systems of compliance and enforcement, and DOE has not included proposed compliance and enforcement provisions in this proposed rule. In the event that DOE addresses compliance assurance in a future rulemaking, paragraphs (e)(1)(i), (e)(1)(ii), and (e)(2) would be reserved to provide a methodology for calculating the R -value of insulation, the R -value of non-insulating materials, and glazed fenestration SHGC that would provide for an accurate and repeatable procedure to determine compliance with the standards proposed under § 460.102(c). The MH working group recommended, however, that U o be determined in accordance with the “Battelle Method.” The Battelle Method is an industry standard methodology for determining U o and is commonly utilized in the manufactured home industry. The Battelle Method's methodology is based on recommendations in the ASHRAE Handbook of Fundamentals but provides more specificity to determining U o for manufactured housing. The Battelle Method provides a step-by-step process for calculating U o by calculating the U -value of each unique area of the building thermal envelope and by calculating a weighted average. Both of these references serve as the basis for calculating overall thermal transmittance under the HUD Code ( see 24 CFR 3280.508) while only the ASHRAE Handbook of Fundamentals is referenced in section R402.1.5 of the 2015 IECC. Finally, § 460.102(e)(3) would authorize manufacturers to determine the SHGC of certain glazed fenestration products in accordance with the prescriptive default values set forth in Table 460.102-6 for consistency with the rationale accompanying § 460.102(d)(8) of this section. Table 460.102-6 differentiates between single- and double-pane windows, glazed block windows, as well as clear and tinted glass. Single- and double-pane windows refer to the number of panes of glass that are in the window assembly. A single-pane window consists of one pane of glass while a double-pane window consists of two panes of glass separated within the window assembly at a fixed distance. The space between the two panes of glass serves to reduce heat transfer through the window. A glazed block window refers to a window assembly that consists of glass blocks that are arranged or laid out like bricks. These types of windows cannot be opened and are typically used in ground level or basement floors for security purposes. The terms “clear” and “tinted” glass characterize the light transmission properties of the glass. Clear glass is uncoated and transparent, admitting all light through its body. Tinted glass instead has an altered chemical composition or surface coating that affects light transmission and color. Different types of tinted glass block and reflect different quantities and types of light. Table 460.102-6 provides proposed default SHGC values for these different types of windows. (c) § 460.103 Installation of Insulation Section 460.103(a) would require manufacturers to install insulation according to both the insulation manufacturer's installation instructions and the instructions set forth in Table 460.103. DOE proposes to require manufacturers to comply with the insulation manufacturer's installation instructions both for consistency with section R303.2 of the 2015 IECC and to ensure that the intended performance of the insulation is achieved. Unlike section R303.2 of the 2015 IECC, however, § 460.103 would not require insulation to be installed in accordance with the International Building Code or the International Residential Code, as the HUD Code already sets forth requirements in this regard. DOE also proposes additional insulation requirements under § 460.103(a) that are based in part on section R402.4.1.1 of the 2015 IECC, with clarifications to account for the unique design of manufactured homes, to ensure that insulation is able to achieve its intended thermal performance. Table 460.103 would include a general requirement that air-permeable insulation must not be used as a material to establish the air barrier. This proposed requirement is consistent with Table R402.4.1.1 of the 2015 IECC, which the MH working group recommended that DOE include this in the proposed rule. See Term Sheet at 1. DOE proposes to adopt this requirement to improve energy conservation in manufactured housing through the reduction of natural air infiltration through the building thermal envelope. Proposed Table 460.103 also includes insulation requirements for access hatches, panels, and doors between conditioned space and unconditioned space. Section 460.103(a) would require each access hatch, panel, and door leading from conditioned space to unconditioned space to be insulated to a level equivalent to the level of insulation immediately adjacent to the access hatch, panel, and door. This requirement would ensure that the thermal performance of the access hatch, panel, or door would be identical to the surrounding ceiling and would ensure that the ceiling insulation achieves the same level of performance as ceiling insulation without an access hatch, panel, or door. Section 460.103(a) also would require each access hatch, panel, and door to provide access to all equipment without damaging or compressing the insulation. Damaging or compressing the insulation would reduce the performance of the insulation and increase the energy losses associated with the ceiling. Finally, each access hatch, panel, and door must be equipped with a wood-framed or equivalent baffle or retainer when loose fill insulation is installed within a ceiling assembly to retain the insulation on the access hatch, panel, or door. That is, an access hatch, panel, or door must use baffles or a retainer to prevent loose-fill insulation installed within a ceiling assembly from spilling into the living space upon use of the access hatch, panel, or door. Each of these requirements have been adopted from section R402.2.4 of the 2015 IECC are consistent with the recommendations of the MH working group, and seek to preserve the performance of insulation within a manufactured home. See Term Sheet at 1. Section R402.2.4 of the 2015 IECC also includes a specification for vertical doors that provide access from conditioned to unconditioned spaces to meet certain fenestration insulation requirements. The MH working group recommended not adopting this specification in the proposed rule because vertical doors that separate conditioned and unconditioned spaces typically are not installed in manufactured homes. Consistent with the recommendation of the MH working group, DOE proposes not to include this requirement in this proposed rule. See Term Sheet at 1. Proposed Table 460.103 includes requirements for installing insulation adjacent to baffles. Baffles must be constructed using a solid material, maintain an opening equal or greater than the size of the eave vent, and extend over the top of the attic insulation. Baffles allow for air circulation from the exterior of the manufactured home to the attic space between the ceiling insulation and the top of the roof. The installation requirement would ensure proper attic ventilation and that insulation would not interfere with a baffle's ability to facilitate air circulation. The proposed requirements would be consistent with section R402.2.3 of the 2015 IECC and the MH working group's recommendations, and would help ensure proper ventilation in attic spaces. See Term Sheet at 1. Table 460.103 as proposed includes a requirement for installing insulation in ceilings or attics. Specifically, the requirement states that insulation installed in any dropped ceiling or dropped soffit must be aligned with the air barrier. The requirement would ensure that there would not be excessive air infiltration through the building thermal envelope if a dropped ceiling or dropped soffit is present in a manufactured home. This requirement is consistent with Table R402.4.1.1 in the 2015 IECC, and the MH working group recommended that DOE include this requirement in the proposed rule. See Term Sheet at 1. To address the unique practice of HVAC duct installation in manufactured homes, Table 460.103 would require insulation to be installed to maintain permanent contact with the underside of the rough floor decking over which the finished floor, flooring material, or carpet is laid, except where air ducts directly contact the underside of the rough floor decking. This requirement is generally consistent with section R402.2.8 of the 2015 IECC, which specifies that floor insulation be installed in direct contact with the underside of the subfloor decking. Given that HVAC ducts in manufactured homes generally are located in the floor space between the insulation and the underside of the subfloor decking, DOE would require the same floor insulation requirements as the 2015 IECC while recognizing the need to insulate around HVAC ducts. DOE requests comment on the proposed floor insulation requirement and whether it would be consistent with industry practice. Table 460.103 as proposed includes an insulation installation requirement associated with narrow cavities such that batts installed in narrow cavities must be cut to fit or filled by insulation that upon installation readily conforms to the available cavity space. This requirement would ensure that all wall cavities are properly insulated, even if they have a non-standard width. This type of narrow cavity could occur in a wall area adjacent to a window frame. This requirement would be consistent with Table R402.4.1.1 of the 2015 IECC, which the MH working group recommended that DOE adopt in the proposed rule. See Term Sheet at 1. DOE proposes to include this requirement in the proposed rule because it ensures that all cavities are properly insulated to achieve the expected thermal performance. Table 460.103 also would require rim joists to be insulated. This requirement would ensure that the entire floor assembly of a manufactured home achieves the desired thermal performance. The requirement is consistent with Table R402.4.1.1 of the 2015 IECC, and the MH working group recommended that DOE include this requirement in the proposed rule. See Term Sheet at 1. Table 460.103 includes an insulation installation requirement that would require exterior walls adjacent to showers and tubs to be insulated. This proposed requirement is consistent with Table R402.4.1.1 of the 2015 IECC, which the MH working group recommended that DOE adopt in the proposed rule. See Term Sheet at 1. DOE proposes to include this requirement in the proposed rule because it would ensure that all wall assemblies with showers and tubs would achieve the expected thermal performance requirements established under § 460.102. Table 460.103 also would require air permeable exterior building thermal envelope insulation for framed walls to completely fill the wall cavity, including cavities within stud bays caused by blocking lay flats or headers. The requirement clarifies the 2015 IECC requirement for wall insulation installation found in Table R402.4.1.1. The MH working group recommended that DOE modify the language of the 2015 IECC requirement to account for the unique design of manufactured housing. See 9/23 Working Group Transcript, EERE-2009-BT-BC-0021-0122 at p. 315. DOE proposes to adopt this requirement, along with the recommended modifications from the MH working group, to ensure that wall assemblies in manufactured homes achieve the proposed thermal performance requirements set forth under § 460.102. Finally, the 2015 IECC contemplates additional specifications for insulating areas associated with the building thermal envelope that DOE has not included in this proposed rule. For example, section R402.1.1 of the 2015 IECC specifies that wall assemblies in the building thermal envelope comply with the vapor retarder requirements of section R702.7 of the International Residential Code or section 1405.3 of the International Building Code. DOE has not incorporated this requirement into this proposed [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2016-13547. Public record. Not legal advice.