I have an existing LEED Certified Core & Shell v2009 Project where there will be an addition of about 40% more. The better approach is to Certify the Addition as a stand alone building, because including the already Certified building is too expensive: fees of the existing part plus the new addition, as well is expensive to make it comply with v4 as v2009 is no longer available and there are new requirements.

My questions:

1- Does it need to be a physically barrier between the existing part and the new addition such as a wall or door, or can I just leave it open or draw a line in the floor to differ LEED V3 Certification and the new addition (a physicall barrier as a wall is not posible for the Project)

2- The existing part is Core and Shell Building, the addition will be completed with interior fit outs of that part so it falls under New Construction Warehouse and Distribution Center. if its not a physically barrier such as Wall or door, is it posible or it strictly need a physical barrier due that the existing Certified Building is Core and Shell LEED v3 and the new addition  NC  v4?

3. The addition will have  separate air distribution systems and it is posible to meter energy and water independently from the other phase, except for the part that some users will be using existing restrooms from phase one as the new addition will only include new male restrooms. Is it strictly needed to include both male and female restrooms in the addition to be able to treat the addition as a new stand alone building?

Just to clarify it will not affect site credits as existing building didn't anticipate SSc3, SSc5.2, SSc7.1, WEc1.

Thanks in advance