I'm trying to decide the best place to draw the imaginary property line between two buildings on the same lot. The two buildings were created by a Fire Wall (due to floor area of buildings).What makes this tricky is that the exterior walls of the two buildings are perpendicular to each other. I want openings in those walls and want them unprotected if possible. No openings are allowed within 3' of the PL. Is this measured as in attached Scenario #1 where walls perpendicular to the imaginary PL don't require protected openings? Or is it more of a "setback" situation as in Scenario #2?If Scenario #2 is correct, can I measure the allowable unprotected openings as I have shown? Treating the wall as three segments, one from 0-5' one from 5'-10' and one 10'+ and then comapring the portion of the opening in that segment to whats allowed?Any insight would be appreciated!Thanks,NealFIRE-WALL2.pdf
Measure perpendicular from the face of the wall, like Scenario 1, not perpendicular to the property line as shown in Scenario 2 (see "Fire Separation Distance" in 702.1).
You end up with 1 wall that is on the property line, and with the other wall 5-feet away from the property line per 706.5.1(2).
You could continue to step the property line to benefit one wall.