Referencing 90.1 Table G3.1.5: I understand that the envelope for an existing building baseline model should reflect existing conditions concerning thermal properties of walls and windows. It also seems to be the consensus that you don't rotate the baseline building as you would for new construction (please confirm...). So this is the question that remains for me: Does an existing building have to follow G3.1.5c for WWR, if a particular face of the existing building exceeds 40%? Or do I follow G3.1.5f literally, including WWR?
Thanks very much for any clarification,
Christian
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5867 thumbs up
February 16, 2016 - 11:37 am
Correct you do not rotate an existing building.
The 40% WWR is for the entire building, not each facade. If the total is under 40% model the baseline identically.
Francesco Passerini
R2M Solution Srl16 thumbs up
February 16, 2016 - 11:48 am
And if the total fenestration for both the proposed building and the existing building exceeds 40%, how shall the baseline model be modeled?
Ragards
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5867 thumbs up
February 16, 2016 - 12:46 pm
That becomes a bit of a gray area. The conservative approach would be to limit the baseline to 40% so that would definitely be acceptable. Modeling it identical to the proposed is less conservative and less likely to be accepted by the reviewer.
Christian Kaltreider
3 thumbs up
February 16, 2016 - 12:58 pm
Thanks. That answers it for me. And thanks to R2M for completing my question.