Is my roof deck legal?

I'd love to see what the notice of violation said if the only furniture up there was wheelchairs.

Verados, That does not sound correct. We have a wooden roof deck in our building with benches which was added a
100 years after the building was built. The roof is only accessible via stairs.

My 1960s-era co-op also has a roof deck (almost the entire roof, really), and it's regularly used, though the elevator doesn't go to the roof, and it's only accessible by stairs, like yours. We do have some furniture out there, for whomever manages to struggle up the stairs and push open the fire door. Don't know what our C of O says.

NYC Building Code requires that decks cover only a certain % of the roof space. Also, there are requirements for distance from building facade and height of required railings. There may also be a limit on occupancy which may explain why your coop does not have chairs. High occupancy raises egress concerns which triggers other concerns (#exits, width of exits, etc.). I am not sure if older roof decks are grandfathered from zoning regs but a new roof deck would certainly need a revised c of o.