Can Building Envelope CxA be the acoustical engineer

Edgar, this seems okay to me—falls outside the main conflict of interest.

I am not sure I agree, Tristan. The standard is not going to cover every single contractual possibility and believe me, I know there can be thousands and thousands. The key concept in Enhanced Commissioning is the requirement for independence from the design effort and responsibility. I agree with Tristen that it is difficult to see there would be a conflict of interest in this situation, but I am not sure that GBCI would see it that way. Acoustical services are very integrated into all parts of a project (or at least they should be...I am a big fan of this service by the way) including envelope, interior materials, walls and ceilings, configurations of spaces, and mechanical systems. So, this is a bit too close for me to say that they would find it acceptable. My recommendation would be to ask for a conference call with your reviewers. Remember, do not just ask "if this is ok." You probably won't like the answer and you will have wasted the opportunity. Provide a clear, well-written justification on why you feel there is no conflict of interest in this particular case and this particular firm.