eLaws | eCases | State of Washington |
 Washington Administrative Code (Last Updated: November 23, 2016)
 Title 51. Enterprise Services, Department of (Building Code Council)
 Chapter 51-11C. State Building Code adoption and amendment of the 2015 edition of the International Energy Conservation Code, Commercial.

  Section 51-11C-40233. Section C402.4.3—Maximum U-factor and SHGC.  

Latest version.
  • C402.4.3 Maximum U-factor and SHGC. The maximum U-factor and solar heat gain coefficient (SHGC) for fenestration shall be as specified in Table C402.4.
    The window projection factor shall be determined in accordance with Equation 4-6.
    PF = A/B
    (Equation 4-6)
    Where different windows or glass doors have different PF values, they shall each be evaluated separately.
    C402.4.3.1 Reserved.
    C402.4.3.2 Reserved.
    C402.4.3.3 Dynamic glazing. Where dynamic glazing is intended to satisfy the SHGC and VT requirements of Table C402.4, the ratio of the higher to lower labeled SHGC shall be greater than or equal to 2.4, and the dynamic glazing shall be automatically controlled to modulate the amount of solar gain into the space in multiple steps. Dynamic glazing shall be considered separately from other fenestration, and area-weighted averaging with other fenestration that is not dynamic glazing shall not be permitted.
    EXCEPTION:
    Dynamic glazing is not required to comply with this section where both the lower and higher labeled SHGC already comply with the requirements of Table C402.4.
    C402.4.3.4 Area-weighted U-factor. An area-weighted average shall be permitted to satisfy the U-factor requirements for each fenestration product category listed in Table C402.4. Individual fenestration products from different fenestration product categories listed in Table C402.4 shall not be combined in calculating area-weighted average U-factor.
    [Statutory Authority: RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-40233, filed 1/19/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-40233, filed 2/1/13, effective 7/1/13.]
RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-40233, filed 1/19/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-40233, filed 2/1/13, effective 7/1/13.