How to apply the enhanced commissioning task to existing?

David, there seems to be two questions, the first being how to do the certification of an existing building under NC, even with the addition. The ones that I have been involved with were "major" renovations and or "major" additions, where the existing building systems were impacted significantly. I am not going to answer that one. So, your question! I agree that you should do a mini retro-commissioning process for any existing equipment that is not going to be changed dramatically. So during your design review, perhaps you include some discovery related to the systems and what they are serving. Then you can make recommendations (if needed) on any energy saving or application updates that should be considered in the project. Then depending on what they include, you would commission to the current or modified sequences. The retro part might be finding components that have failed, or other problems that would be addressed as a change order, or perhaps getting the owner to include an allowance to cover this kind of problem, and if it is not used, it would go back to them.