I recently purchased a home built in the 1920's, the main house is all plaster and in generally good shape and feels well insulated. The attached (but inaccessible from inside) garage at some point had a room placed over it, so it does not have an attic space and the room below is the garage (which I don't think it's insulated, but the ceiling of the garage is covered with cement board along with the walls.
The room over the garage is 17x17 with the ceiling being 6 ft from the floor at the edges and about 8 foot in the center. The room itself has about a 4 inch slope (i presume from the org. garage) so entering the room to the back has a 4inch drop total. Walls are drywall with carpet floor. The door to the room is off one of the bedrooms and that bedroom has a inside window and door (which i presume at one time led to a deck)
The issue I am encountering is that this room is much more susceptible to tempature than the rest of the house, meaning in the summer it can be a good 10-15 degrees hotter, and the same in the winter (especially at night). I currently use this room as an entrainment room with my TV and gaming center (due to it's nice size and shape).
I had just found out that there was a rather breezy draft coming from the baseboards, mostly due to the 4 inch slope leading to larger gaps between the bottom of the drywall and the floor, these were covered up with teh baseboard but when i pulled them away you could see around a 3-4 inch gap between the baseboard floor and outside wall (which has a layer of fiberglass insulation). I purchased a brick of the blown in cellulose insulation, and hand packed the baseboard area as tight as i could to cut down on that draft, which it did, but the room is still quite cool. There are 10 windows (not including the inside one) all oriented on one end of the room (5 per side) These are brand new 2x pane windows, so there is no draft there.
I was thinking of blowing insulation into all the walls, but what about the ceiling? is it easy to blow into that as well? I was also thinking of blowing into the garage ceiling as well. I was thinking that the lack of attic space above causes a large loss/gain of heat as well, is this correct? I love this room and don't want to be unable to use it comfortably when weather is bad. Does anyone have other suggestions on what I could do with this room?
I guess I will add that the room does have around a 6 foot radiator which does warm the room when it's on, only problem is that the thermostat is in the living room on the 1st floor which is about the furthest point from this room.