We used Ecotelligent Homes of Farmington Hills and find them to be an excellent contractor…Their analysis uses a blower door, infrared camera, natural gas/carbon monoxide detectors, and visual inspection of attic and other areas of the thermal envelope. Our concern was not only insulation effectiveness but also indoor air quality … does the house “breathe” adequately or excessively? It was pointed out that the cold air returns and can lights leaked attic air into the house. So we decided to invest…with them to bring our attic insulation up to Energy Star R49 rating, sealing the rim joist in the unfinished portion of the basement, and reducing furnace duct leaks with a process called Aeroseal…We invested this money to further decrease the CO2 produced by our home heating. We all need to do our part…to reduce this as we heat/light our homes and choose our vehicles. Energy conservation is the best way.