To install insulation in a crawl space, cover the vent openings with crawl space vent covers, seal the rim joists with rigid foam board insulation, and use foam sealant to seal gaps between the crawl space wall and sill.
Attic insulation levels are measured by R-Value, which indicates resistance to heat flow. Most attics should be insulated to R-38, or about 10 to 14 inches, depending on the insulation type.
R-Value measures insulation’s ability to resist heat flow, with higher R-Values indicating better thermal performance.