Puzzling items regarding near future basement remodel
I've been doing as much research as possible, reading from numerous sources / books / etc but a few questions have been on my mind that I haven't found a definite answer to. Hopefully someone can help clear these items up for me.
I have a 1600sq ft basement and plan to leave two rooms unfinished (~500sq ft) for utility and storage. The rest will be finished using xps against the walls for insulation / barrier including directly on the floor.
In the unfinished rooms I wasn't planning on having any finishing including no xps against the walls, just bare concrete and exposed ceiling / floor. Would these rooms typically be left bare? I am concerned that if the rest of the basement is finished and warmer due to insulation then there will be a barrier between cold and warm and it will invite condensation at the wall between the spaces. Is this a concern? Do you even insulate this wall between the finished and unfinished space? Is there a risk of mold forming from the unfinished side due to there being no vapor barrier?
When adding service doors / panels (to access water line soffits etc ) is there a preferred way to handle this? Are these doors typically just made from plywood with hinges or is there a premade door / screen that can be purchased? I want it to look as seamless and clean as possible.
When handling soffits around ceiling pipes what do I put on them to give the greatest access to pipes or do I only leave access doors where there are knobs? The rest of the room will most likely be a drop ceiling (I have needed the plumber to come a couple times and the convenience of an open floor is great) but not sure if I should just use OSB screens or is there a better way to handle access for large areas of pipe. I am most concerned about the pipes for the bathrooms.
When using xps on the floor how do you handle the other materials on the floor? Is the plate attached to the concrete directly throught the xps? Is the subfloor then attached directly through the xps? I believe I saw HoH doing this but not 100% sure. I suppose I want to make sure if the bottom plate is attached on top of the xps that it will be a stable enough surface for the plate to sit on.
I have a exterior hatchway with a giant old door that I would remove and put in a more standard sized door that lines up with the new framing. Are there any thoughts on this door and if there is code for if it has to be fire protected now / sweeps / locks / etc? The hatchway could probably use being reset at some point as well as there are some gaps around it.
The basement is pretty temperature all year round, its warming in the winter here in CT than the rest of the house and cooler in the summer. With the insulation added along all the walls is there a need for heating in the basement? I initially thought that a freestanding heat unit may be fine but I've read that electric baseboards sometimes are preferred. I want to make sure I plan for it correctly in the beginning so I don't have to backtrack.
7) I have central air (with the ducting in the attic) that is not accessible in the basement. I have old cast iron heat so no ducting at all in the basement. I have read that its preferable to have air pumped into the basement and pulled out. With no HVAC available how can this be done? Would the air be stale? I am considering purchasing a Santa Fe full room dehumidifier which does allow for ducting it to a room to pull air. Would this be enough?