I have a unique situation I’m working through with running BOMA calcs (at least I think it is unique, perhaps not.) The basic question is what constitutes a structure being a building on it’s own versus a multi-building set?
I am running calcs on “two” structures with unique addresses that are connected on multiple floors by a small connector (maybe 10’x10’). These are old buildings that have recently been completely renovated. When they were renovating, a good deal of their infrastructure was updated and they now share these (Fire pump rooms, electrical, etc). However, they also still have some distinct BSAs that only serve the building where it is located.
To complicate things even more, one of the buildings only has only one exit stair and cannot function on its own with exiting without going through the connector and elevator lobby of the other building and using one of that building’s two stairs.
When renovating, the building the owners did consider separating all of the BSA, so they could possibly sell one of the buildings without the other down the road, but it was prohibitively expensive, so they combined many of the BSA areas and neither building can be sold on it’s own (without major, major work.)
At what point does it shift from being a multi-building set with Inter-Building calcs just being to one building? There would be a huge web of “Interbuilding” areas. I think the owner would prefer it be treated as one building (using Method B), but I want to make sure I’m approaching it correctly.
Bullet Points:
-Building A is 6 stories
-Building B is 3 stories
-Building A has all the new amenity spaces that would be shared with all tenants in both buildings
-Most of the newly combined BSA is in Building A, but there is some shared BSA in building B
-Building B has the “main entrance” to both buildings that passes by Building B’s unassuming elevator and leads to building A’s lobby and elevator
-Building A must use a portion of building B for exiting purposes. It could never function per code without access to the stairs
-Both have passenger elevators that both have access to
-Only Building A has a freight elevator that serves all floors, and both have access to it
-Both have gang restrooms on each floor, both have access to both restrooms
-Both have electrical rooms on each floor
-Both have rooftop/penthouse with building infrastructure

Thank you for any light you can shed.