Just bought a nice project houseboat that I'm planning on living in. The previous owner has done a lot of work to her and it looks really nice inside. Everything is new. My issue is of course insulating this boat for winter, and replacing the windows with something better. My thought on this is to just do 2x2 framing on the inside and then use the pink Styrofoam insulation. As to the windows (the 2 Large single pain 70x48 sliders) I thought I could use these http://www.lowes.com/pd_319330-40446-748171612775_0__?productId=3119707 (I would have to make to 1.5 inch larger to fit) But the cost of 267.23 each is an order of magnitude cheaper than anything I have been able to locate in the houseboat world as replacement. Anyways, open to ideas here since this is my first houseboat.