building a skylight

I assume that the apartment does not own the roof? If that is the case, the roof is common space, and you can't just take over common space. Coop or condo? Either way, you are likely to have to pay (perhaps dearly) to buy the common space (perhaps increasing your maintenance), and the mechanics of doing so differs between coop and condo. And, the responsibility for leaks, etc. will then be yours.

If you can give the architect an "as built" copy of the building's plans, then you could get a rough idea of the costs. Your desire for skylights could impact the other owners if there is currently a roof deck or if the roof needs replacement due to its current condition. There is also the on-going liability of the inevitable skylight or roof leaks at some point in time. There are contractors who specialize in skylight installation . Try the Velux website for their certified installers.

DR: I wouldn't count on being able to put a skylight in the roof to gain an additional bedroom.

@nyc_sport -- thanks for the advice. it's a coop so you're right - roof is shared space.
@raddoc -- thanks! i'll ask for the "as built"copy of the building plan. there is no roof deck. will check out velux now.
@nyc10023 -- thanks, i'm not looking for another bedroom. i just want some light into my kitchen.

dronanjane, do you have a reason to believe that the board will say yes? I know someone who tried to do this, and the board's collective jaw dropped. They said it's like building a new shoer on the stair landing. And that was a pretty liberal board.

"shoer" —shower:)

@commoner -- it's a good question and i don't have an answer to that. and there is no way i can truly find out till after closing. it's not a make or break for me, thankfully, since i like the rest of the apartment quite a bit.

Hey there! How did this turn out dronanjane? Facing the same situation now. THX!

Assuming you are planning for a townhouse, you will have to address:
1. How will the joists be supported where you make a cut for a skylight which is wider than the spacing between the joists?
2. Asbestos abatement when you remove part of the roofing material.
3. Most importantly, who owns the roof? If you have roof rights, you can do it.