My client is doing an interior renovation of a small office at the ground floor in an existing mixed-use building. Over the office there are residential units, and below it there is an underground parking, which is unheated. This renovation does not affect the facade. Would it be necessary in this case that both the office facade and floor comply with the mandatory provisions and prescriptive options of ASHRAE´s 91.1 2007 Section 5 (i.e. referring to the envelope)? In particular, should I insulate the office floor, which is made of reinforced concrete, and change the facade? If compliance with Section 5 were not applicable, how could I justify that the envelope is not part of the renovation project?
Would the exterior office envelope have to meet the former ASHRAE requirements were some of the windows replaced?

Thank you in advance,