Our project is a residential dormitory on a university campus, registered under LEED NC version 2.2. Smoking will be allowed in the units, so we will be satisfying EQ prerequisite 2 with option 3. This CIR asks if tracer gas testing, as opposed to blower door testing, can be used to satisfy the testing requirement. In LEED NC version 2.1, tracer gas testing was required to verify acceptable sealing. Then a CIR dated 12/3/03 allowed for blower door testing as a substitute. A CIR dated 5/3/04 indicates that the decision to allow blower door testing was made because blower door testing is more economical: "The 12/3/03 credit ruling that provides for blower door testing resulted from a combined effort...to find a more economical approach for residential projects to achieve this prerequisite." However, in LEED NC version 2.2, it appears that only blower door testing is allowed. The vendor that has been retained for our project has indicated that tracer gas testing can more accurately assess the potential for air movement between dormitory rooms than blower door testing and therefore should be the preferred methodology. Blower door testing can give false results due to leakage from a room to the outdoors, rather than the room-to-room leakage that is the point of this prerequisite. This is a special concern with our project because each room has large operable windows - nearly floor to ceiling and wall to wall in many units, representing a significant portion of the unit envelope surface area. Blower door testing would penalize us for the unavoidable leakage area associated with the perimeter crack of these windows, even though that crack would not lead to contamination of adjacent rooms. Tracer gas testing, on the other hand, more accurately measures the sealing requirement of this prerequisite by measuring actual gas leakage from one room to another. Will it be acceptable, under LEED NC version 2.2, to use tracer gas testing instead of blower door testing to satisfy the testing requirement in option 3 of EQ prerequisite 2? Performance of differential air pressures would still be verified by separate testing as required.