LEED CI EAp2 - ASHRAE 90.1 building envelope compliance

Michele Helou

Principal

Sage Design & Consulting

LEEDuser Basic Member

55 thumbs up

December 5, 2013

Can anyone tell me if the addition of interior storm windows without a change in existing fixed windows would trigger having to meet either the prescriptive requirements or the ECB ch. 11 model requirements? It seems to me, the storms only make it better. I see that ASHRAE 5.1.3 makes an exception for storm windows as well as other envelope 'improvements'. . does this prerequisite allow all of the exceptions in ASHARE 5.1.3?

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Thu, 12/05/2013 - 19:46

It would not require you to meet the prescriptive requirements. That is the exception under 5.1.3. For the Section 11 model the baseline would be the prescriptive requirements and the proposed would be the installed windows with storms.

Michele Helou

Principal

Sage Design & Consulting

LEEDuser Basic Member

55 thumbs up

Thu, 12/05/2013 - 22:43

and on insulating an existing mass wall - assuming we need to comply with section 5 for insulation values - ASHRAE section 5.5.3 would send us to Normative Appendix A for an allowable calculation?

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Fri, 12/06/2013 - 16:21

If you are adding insulation to an existing wall then it is my understanding that you would need to bring it up the prescriptive value or follow the performance path in Section 11. Yes Appendix A is a allowable methodology for determining the whole assembly performance of various construction assemblies.