A client has approached our team to review a project proposal intended for LEED certification, it is not a typical project, so some assistance at providing clarification per our concerns on the MPR, including determining the most ideal rating system to adopt would be of great value.

Background:

The LEED Project Team has taken a look at the size and scope of the project in relation to its existing features and desires confirmation with regards eligibility to register under the LEEDv4 BD+C rating system or consider LEEDv4 ID+C; the existing building is a residential building with four (4) floors and consisting of a total of thirty-seven (40) residential units with a total GFA of 3751.4sqm, however the area to be remodeled on the first floor is the existing storage area (directly located under the 2nd floor) south side; which is to be converted to Six (6) new additional residential units. 

With our understanding of the v4 BD+C rating system both MPR1 and MPR3 have been met but the last category MPR2 has some eligibility concerns. 

Question:

All Six (6) new suites would have main entrances to the exterior with additional egress routes connecting to an existing common lobby on the interior; the GFA of the area required for construction (to include entirely new envelope, electrical and mechanical systems) is 345.6 sqm, however the limited portion of the building vying for certification is only about 9.21% of the entire building, which is not an extension but built into the original building... Now the concern is the eligibility of this section on the ground floor vying for LEED certification as a separate entity from its parent building not being upgraded to LEED status. Boundary consideration (MPR2) under LEED v4 BD+C requires clarification, otherwise... should another rating system be considered?

Thank you everyone for your help providing insightful clarification and valuable responses.