I am modeling a building that will be classified under major renovations for LEED v2.2. I see that there is a different savings percentage required for this, but I am looking for some guidance on how to model this.

The reference guide says that the baseline envelope parameters should be modeled as they exist rather than ASHRAE 90.1. What does this include? Should I still take out shading devices? How are differences in scheduling and internal loads modeled? Can I take advantage of a new water heater? The majority of the shell is being redone, can I assume that the building will be tighter in terms of infiltration?

The new building will be used a little differently and there is a small addition. Also, this building will use the existing mechanical system that was installed about 8 years ago. I have the specifications for the system, but it is probably not operating at the same efficiency that it was when it was installed. Does anyone know of a good way to model an older system?

If you could give me any advice or point me towards more information, I would really appreciate it.

Thanks,

Tim Johnson, EIT, LEED AP