Section R402.3—Fenestration.
R402.3 Fenestration. In addition to the requirements of Section R402, fenestration shall comply with Sections R402.3.1 through R402.3.6.
R402.3.1 U-factor. An area-weighted average of fenestration products shall be permitted to satisfy the U-factor requirements.
R402.3.2 Glazed fenestration SHGC. An area-weighted average of fenestration products more than 50 percent glazed shall be permitted to satisfy the SHGC requirements.
R402.3.3 Glazed fenestration exemption. Up to 15 square feet (1.4 m2) of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in Section R402.1.2. This exemption shall not apply to the total UA alternative in Section R402.1.5.
R402.3.4 Opaque door exemption. One side-hinged opaque door assembly up to 24 square feet (2.22 m2) in area is exempted from the U-factor requirement in Section R402.1.2. This exemption shall not apply to the total UA alternative in Section R402.1.5.
R402.3.5Combustion air openings. Where open combustion air ducts provide combustion air to open combustion, space conditioning fuel burning appliances, the appliances and combustion air openings shall be located outside of the building thermal envelope, or enclosed in a room isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table R402.1.3, where the walls, floors, and ceilings shall meet the minimum of the below-grade wall R-value requirements. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it passes through conditioned space to a minimum of R-8.
EXCEPTIONS: | 1. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside. |
| 2. Fireplaces and stoves complying with Section R402.3.6 of this code and Section R1006 of the International Residential Code. |
R402.3.6 Fireplaces. New wood-burning fireplaces shall have tight-fitting flue dampers or doors, and outdoor combustion air. When using tight-fitting doors on factory-built fireplaces listed and labeled in accordance with UL 127, the doors shall be tested and listed for the fireplace. Where using tight-fitting doors on masonry fireplaces, the doors shall be listed and labeled in accordance with UL 907. Gas fireplaces shall comply with the efficiency requirements in Section R403.7.2.
[Statutory Authority: RCW
19.27A.020,
19.27A.045,
19.27A.160 and chapter
19.27A RCW. WSR 24-03-084, § 51-11R-40230, filed 1/16/24, effective 3/15/24; WSR 23-02-060, 23-12-102, and 23-20-022, § 51-11R-40230, filed 1/3/23, 6/7/23, and 9/25/23, effective 3/15/24. Statutory Authority: RCW
19.27A.020,
19.27A.045,
19.27A.160 and chapter
19.27 RCW. WSR 20-01-047, § 51-11R-40230, filed 12/9/19, effective 7/1/20. Statutory Authority: RCW
19.27A.020,
19.27A.045,
19.27A.160, and
19.27.074. WSR 16-02-127, § 51-11R-40230, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW
19.27A.020,
19.27A.045 and chapters
19.27 and
34.05 RCW. WSR 13-04-055, § 51-11R-40230, filed 2/1/13, effective 7/1/13.]
