We are pursuing EA Credit 1, Option 2. We are using "Advanced Energy Design Guide for Small Office Buildings" (Achieving 30% Energy Savings over ASHRAE 90.1) in lieu of energy modeling, as allowed by LEED Reference. We are remodeling a historic building. Many "Envelope" items are existing conditions for this building. Would it be acceptable if we pursue an "overall" envelope that meets or exceeds the recommendations for envelope construction? For example, we will be able to exceed recommended R values in the roof, but we have some existing exposed brick that must remain un-furred. Or, can we exclude some existing conditions and historical conditions from our requirements for envelope R values and SHGC (for glass) values?
The existing building project is seeking EAc1 credit using Option 2: the "Design Guide for Small Offices" compliance approach. The project is seeking an alternate envelope compliance approach using either an "overall envelope" approach or exclusions for existing and historical conditions. Exceptions and/or alternate compliance approaches are not permitted under EAc1 Option 2. The Design Guide for Small Offices was compiled based on multiple energy performance simulations that confirmed the cost-benefit of the recommended measures. The comparative benefits achieved through alternative compliance methodologies cannot be verified without additional energy simulation. Unless the project team can document that the project fully complies with all the prescriptive measures of the Design Guide for Small Office Buildings, a separate compliance path (either Option 1, or Option 3) must be taken to document points under EAc1. Applicable Internationally.