With the right prep work, a double layer of OSB might be better than a slab
To keep sewer gas out of a house, pay attention to fixture traps, the integrity of the exit plumbing, and whether or not the house has balanced ventilation.
Installation details must perform as well as the window itself
Once you know your target R-value - half that of the above-grade walls, or roughly one-quarter the R-value of the roof - here's how to choose and install the proper insulating material.
