Hi all

We are working in an office project that we would like to apply to the commercial interior LEED Certification. The office is in an existing building, with a surface of 1.500 m2. The building has a curtain wall envelope that used a simple glass that not match entirely the specification in the table 5.5-1 zone 1. The glass is compound with one layer that has a U value of 5.814 and a SHGC of 0.258. The second layer has the same U value and a SHGC of 0.51. We cannot modify the fenestration area.

According to ASHRAE 90.1-2010 the WWR has to be < 40%, but reviewing the information and how there are different points of view regarding the scope of the project we would like to ask:

1. Do we have to build internal walls in order to achieve the WWR < 40%? Or because this is an existing building the curtain wall is out of the scope?

2. In case that we do not consider the office envelope, if we go with the Option 2. Prescriptive Compliance, the same option apply in the EAC2?

Thank for your support