LEED Interpretation #10265 made on 01/01/2013 provides the best official guidance for this situation. The approach that is approved in that situation involves multiple buildings, all being certified to LEED-NC. The ruling allows the project to track together all demolition and construction waste diverted, and to then apply a weighted average based on gross square footage to each LEED project. Each building must meet the required threshold for waste diversion in order to earn the credit and in addition, the Construction Waste Management (CWM) Plan must outline goals for diversion for each building, not just as an aggregate across all projects.

If your project is in a similar situation but with different specific circumstances, LEEDuser would recommend adopting that advice as closely as possible, while accounting for any differences in a way that meets the LEED credit intent. Some projects may want to get an official ruling—either a CIR or LEED Interpretation.