Hi,

we’re working in a project of an existing office building (10 floors) pursuing LEED CI certification. We are following option 1 under EAp2 and our doubt is related with envelope issues.

Since we’re talking about an existing building, built 30 years ago and with missing documentation, if existing envelope thermal characteristics are not known, can we use any default values of thermal characteristics to model proposed building energy performance (e.g. for glazing properties ASHRAE 90.1-2010 Table A8.2)?

Regards,