WAC 246-359-500. Window construction requirements

(1) All habitable rooms and spaces must be provided with windows the total area of which must be not less than one-tenth of the floor area.

(2) At least one-half of each required window must be able to open for ventilation purposes.

(3) Every sleeping room must have at least one operable window or door for emergency escape or rescue directly opening to an outside area to provide a clear escape away from the building.

(4) Escape or rescue windows must have:

(a) A minimum net clear openable area of five point seven square feet; and

(b) A finished sill height not more than forty-four inches above the floor.

(c) The following minimum net clear openable dimensions:

(i) The height dimension of twenty-four inches; and

(ii) The width dimension of twenty inches.

(5) All operable window openings must be screened with sixteen-mesh material.