Convenience door between 2 separate properties

[Yikes]

Client owns 2 adjacent lots, each with a separate building with zero setback on the shared property line.
Sometime in the 1980s or earlier a 3' wide door opening was created between them at the 2nd floor level, for convenience.
The door is fire rated 120 minutes, just like the wall rating on the building.
Buildings are too big to collectively be calculated as a single structure.
I have no records of a building permit, but this client is the type that does not bootleg things.

Was there some code back then that allowed openings on a property line wall?

 

[Yankee Chronicler]

BOCA allowed horizontal exits. I'd have to dredge up one of the old BOCA code books but I don't think the language was such that it made any difference of the "property line" between two buildings was an actual property line or an imaginary property line.

Back then, of course, California was under the ICBO. I used to be licensed in California but that was a long time ago and I don't have access to any ICBO books now, so I can't help with specific references.

 

[Yikes]

Thanks! And yes, the property in question is in CA. I have an old copy of the 1988 UBC, and though it does have horizontal exits (good ol' Chapter 33), when it comes to 2003(b) openings in walls, it simply says "no openings shall be permitted in exterior walls of groups A, E, I, and B, divisions 1, 2, and 3 Occupancies less than 5 feet from the property line, and no openings in Groups B division 4 and M occupancies less than 3 feet from the property line."

 

[Yankee Chronicler]

Thanks! And yes, the property in question is in CA. I have an old copy of the 1988 UBC, and though it does have horizontal exits (good ol' Chapter 33), when it comes to 2003(b) openings in walls, it simply says "no openings shall be permitted in exterior walls of groups A, E, I, and B, divisions 1, 2, and 3 Occupancies less than 5 feet from the property line, and no openings in Groups B division 4 and M occupancies less than 3 feet from the property line."

Well, that provision sounds a lot like the IBC provisions calling for fire-resistance ratings when close to a property line or to a fire separation line. Except that the IBC doesn't strictly prohibit openings in walls close to the lines, it prohibits unprotected openings. Are there any exceptions following that paragraph from the UBC?

However, in your case the walls aren't close to the fire separation line, they are on it. I guess the question is, you said there are two lots and two buildings. Are there two exterior walls with a zero fire separation distance, or do they share a common party wall? If it's a single party wall meeting the definition of a fire wall under the IBC, I don't see any problem. If it's two separate exterior walls, and ONE of them has a rated door and frame in it -- then the other has an unprotected opening, and that's a problem (technically).