We have been building the house to a 4 star Built Green level. Built Green is our local Master Builders Association, green building program. Building to this level exceeds current building and energy codes and to qualify at this level we needed to use a 3rd party to verify our points. Today, Chris of O'Brien & Company came to verify a bunch of our items and do the blower door test. This tests the air tightness of the house and can help locate any air leaks coming. The house is depressurized with a fan in the door and a rating is taken. We had taken steps prior to this, to seal the house as best we could. Mainly Neil and crew went around and caulked along the exterior plates, wall intersections and sealed the electrical outlets, but I think it was his tight framing and care throughout the building process. We not only met the lowest Built Green rating but surpassed that by half as much. Basically we aced this test. What that means is that we have more control on how fresh air enters the building. We have fresh air vents in the windows of the living room, dining room and bedrooms. What we don't want is air being pulled in by the ventilation fans from the attic space, walls or crawl space.