We have a project that is a major renovation of an existing building. We are planning on using the Existing envelope pathway - and thereby keeping the existing envelope in both the Proposed and Baseline building, which also allows us to take credit for improvements of the envelope in the Proposed building.
How is this handled for parts that are new construction? The building is expanded with 3 more floors on the existing top floor. Is it possible to comibine existing and new construction so that in the Baseline we use ASHRAE 90.1-values for the new construction and existing envelope for the lower floors? Also, since the baseline building shouldn´t be rotated for an existing building - is this ignored for the top floors as well (new construction)?
Thanks in advance,
Regards,
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5919 thumbs up
May 13, 2015 - 9:23 am
The new construction uses the Table 5.X values for the Baseline. The lower portions which were existing can use the previous condition. So yes you combine the methods. As long as the addition is less than 50% of the total you do not need to rotate the baseline.
Neeraj Sharma
Sustainability ManagerConserve Solutions- Riyadh, Kingdom of Saudi Arabia
1 thumbs up
February 4, 2025 - 4:50 am
Mr. Marcus,
I'm using the existing envelope values for my baseline case, but I'm unsure about the Window-to-Wall Ratio (WWR) for the floors. Should I maintain the existing 98% WWR or reduce it to 40% while keeping the envelope values the same?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5919 thumbs up
February 4, 2025 - 10:23 am
Which version of LEED/ASHRAE 90.1 are you using? This forum is for an older version of LEED that has sunset.