The depth of insulation is 2 ft - it was blown in. I also insulated the garage doorways with styrofoam panels received at copyright (There is certainly a certain kit for this). Beforehand, the garage and lani weren't insulated. I like SolaTubes and experienced four in my very first house https://solarcompanyinsriganganag83715.pages10.com/solar-company-in-sriganganagar-things-to-know-before-you-buy-70238730