Framing basement with foam board insulation – GreenBuildingAdvisor

Hanging drywall from 2×3 should not be a problem, any way you slice it. Drywall screws only need to fasten about 0.5″ into the wood, and if you have 1.5″ depth to work with, that’ll be plenty. You can even drill through for electrical lines as needed. (Just be sure to use a nail plate if there’s any cable or pipe less than 1″ from the surface of the timber element, to prevent future accidents.) If you’re using normal electrical boxes, though, you may need to carve out some of the foam behind in order to get the appropriate depth. They do make shallow boxes, but depending on how many wires are coming in and out, you have to calculate if these are too small a volume.

Hanging drywall against “flat” framing is so much easier than the normal way. In this case, you have a solid 2.5″ width to land side-by-side sheets, rather than the typical 1.5″.