After three months of public review, DPD and Seattle City Light staff met to decide on initial staff recommendations for the 2009 Seattle Energy Code. These recommendations were subsequently forwarded to DPD’s Construction Code Advisory Board (CCAB) in late April.
CCAB met on May 6, 2010 to discuss the staff recommendations for the 2009 Seattle Energy Code. There was a review of key topics and some questions and comments with resulting recommendations for minor changes to some sections of the text. The CCAB discussion then focused on two issues:
- The fenestration U-factors for buildings with a fenestration area that was 30-40 percent of the gross wall area (whether to recommend that DPD relax the proposed U-factors).
- Seattle EnvStd (whether to recommend that DPD develop and include an updated version of this software).
Subsequent to the CCAB meeting, DPD and Seattle City Light staff received preliminary energy modeling results comparing the draft 2009 Seattle Energy Code to ASHRAE/IESNA Standard 90.1-2007. While that analysis is still being fine-tuned, for a three-story office building, the energy savings estimates are between 10-20 percent. This is less than the 20 percent energy savings specified in City Council Resolution 30280.
Based on comments received from CCAB and others, additional revisions were made and forwarded to CCAB. CCAB met on May 20, 2010 and voted unanimously to endorse the May 18, 2010 draft of the 2009 Seattle Energy Code with two modifications:
- Reinstating Seattle EnvStd, meaning updating the software for 2009, with specific criteria for the visible light transmittance.
- Modifying Table 13-1 to allow U-0.38 metal frame windows (less stringent), allow less stringent U-factors for up to 10 percent operable metal frame windows that meet certain criteria, and to require a minimum visible transmittance of VT-0.51, with some accompanying changes to address the trade-off methodologies.
Following the CCAB meeting, DPD and Seattle City Light staff discussed these CCAB modifications, and they recommend that we accept the CCAB modifications and incorporate them into our proposal as we go forward.
The next steps are for DPD to develop a draft ordinance, send that to the Law Department for review, then to forward recommendations to the Mayor. City Council consideration would occur after that, most likely in July or later. The effective date will coincide with other Seattle code updates, and depends on when the ordinance is approved by the City Council and signed by the Mayor.
City staff thanks everyone for their participation and contributions to the 2009 Seattle Energy Code. For further information, contact: