Sorry mods, didn't know which forum this belonged in...feel free to move My river house is cold. It's 1400 sq ft and I'm heating it with the CW2500 insert. Overnight, the temp will drop 10' in the house if it's 30' outside, and that's with me lighting a fire right before bed. In contrast, my main house might drop 5' or so, without any fire overnight. The main house has a much smaller stove, and is heating a much bigger (2000 sq ft) area. It does have one shared wall, a basement, and good attic insulation, but original (100 year) windows and no wall insulation (brick only). At the river: 1. It's cinder block construction, looks like at best I have 5/8" XPS foam on the outside. The one exterior wall I've removed just had drywall on furring strips on the blocks, so I assume I don't have full stud cavities anywhere (though I guess I should at least check) 2. It's leaky. I'm working on that. 3. It sees a lot of wind. Not much I can do about that. 4. 300 sq ft is a converted screened in porch. Basically all glass on a concrete slab. Lovely when it's warm. The area above isn't accessible from the attic, but I pulled a couple of can lights and found a half-hearted attempt to insulate that area. 5. Rest of the ceiling is accessible, and is mostly covered with a combination of blown rock wool and batts. At best I'm looking at R-21 up there. 6. Rest of the house is on a R-21 insulated crawlspace. To add insult to injury, I only heat the place to 42' when I'm not there. I installed a wireless t-stat so I can pre heat it, but when it's real cold (ie, when I need it), the heat pump struggles. Then it takes a LONG time to get it warm in there. So, what are my options? I've been sealing leaks, installed airtight cans. The obvious (?) next move is to blow in some insulation in the attic, but I'm skeptical that this will make much of a difference given the other obstacles. So, will the extra insulation make enough of a difference to feel it? During the day, my attic is definitely warmer than it should be, and I can see heat radiating off the roof, so I'm thinking it will... Anything else (reasonable) that I can do?