I have a project to certify in France, this is an existing building which will be occupied during the work. The functionality of the building will be change for approximately 60% of the building. Then, we have two different option for the optimization of the project.

For the first one, two basements and one floor on the top will be added, the external structure won't change less the windows, the different systems will be change and renovated and the floors too. For this one, I think that the better referential is the LEED BD+C for Major Renovation.

For the second option, only one basement will be added and only the glass of the windows (not the frame). For this one, I think that the better one is the LEED EBOM.

Could you please confirm my choice. I don't know if the fact of added a basement underground have an impact of he referential nor if we change the functionality of a major part of the building.

Thanks in advance for your help.