According to this map, Mill Valley is in zone 5. Assuming your heating system is natural gas, the recommended insulation level for a crawl space is R-13, walls are R-13 and attic space is R-38.

Cover the crawl-space floor with a 6-mil vapor barrier, and provide an air passage between the living area of the home and the crawl space. If you have forced-air heating, open a duct to the crawl ...

“Most homes, unfortunately, do not have insulation in the crawl space,” said Krieger. “It is mostly done on a retro fit basis, and is something we deal with quite frequently.

“Most homes, unfortunately, do not have insulation in the crawl space,” said Krieger. “It is mostly done on a retro fit basis, and is something we deal with quite frequently.

Homebuyers increasingly seek energy-efficient features, and if you're planning to sell, potential buyers will love seeing that your home has an adequate layer of insulation in the attic crawl space.

My wife and I live in a 50-year-old house in North Carolina, and our crawl space can get quite funky from dampness and humidity. At least some of the current fiberglass insulation is in need of ...