I'm currently building an attached 26x26 garage to a house that sits on a crawl space in Northern Michigan. The house crawl space foundation walls have 3" (R-15) XPS insulation on the interior of the crawl space.
I insulated the inside foundation walls of the garage foundation on three sides with 4" (R-20) XPS insulation down to the footer. My question is should I dig down along the house foundation wall to the footer where the garage will connect to the house and put some XPS insulation there even though on the other side in the crawl the foundation is insulated? I was thinking if I added some XPS insulation on the outside wall of the home foundation at this location, the garage foundation/interior would have a complete thermal break from the house. Just wondering what everyone's thoughts are on this. I already have the insulation so it's not a cost issue. Just wondering if there is a benefit doing this or not. I have attached some pics.
I insulated the inside foundation walls of the garage foundation on three sides with 4" (R-20) XPS insulation down to the footer. My question is should I dig down along the house foundation wall to the footer where the garage will connect to the house and put some XPS insulation there even though on the other side in the crawl the foundation is insulated? I was thinking if I added some XPS insulation on the outside wall of the home foundation at this location, the garage foundation/interior would have a complete thermal break from the house. Just wondering what everyone's thoughts are on this. I already have the insulation so it's not a cost issue. Just wondering if there is a benefit doing this or not. I have attached some pics.
