The depth of insulation is 2 feet - it had been blown in. I also insulated the garage doors with styrofoam panels obtained at copyright (There may be a particular package for this). Earlier, the garage and lani were not insulated. I like SolaTubes and had four in my initially https://solarcompany45666.laowaiblog.com/33867195/a-simple-key-for-solar-energy-unveiled