Ok, so we bought a house back in Sept. The previous owners added onto the living room, and created an attic space over that addition (the rest of the house has no attic), but didn't put in any way to access that attic space. We had a chimney fire and now need to access the attic space to replace the pipe. We also want to check on the insulation as we had ice dams this winter.

So, I assume the first thing I need to do is figure out if was done with trusses or beams since that will dictate the easiest size and shape of the access hatch? Is there anyway to do that with out punching a hole in the ceiling and looking?

Once I've figured that one, cut a hole of appropriate size, cut a panel in the required size, frame the hole with trim (attached to the ceiling beams/trusses with drywall to wood screws?) for the panel to sit on. Add some weather stripping to the hatch and insulate the hatch door itself?

Am I missing anything obvious?

(if there's already a thread on this please point me to it, I looked but couldn't find it.)