Foundation Air Barrier Installed
Air and water vapor can enter a home by diffusing through building materials or by infiltration or air leaks. In many ways a house, due to wind pressures, act like the cabin of an airplane that experiences large pressure differences inside and outside the cabin. In the case of an airplane, a poorly sealed cabin would result in a very uncomfortable and cold ride for the passengers (not to mention there would be too little air to breath). And while a house does not deal with the effects of the upper atmosphere, it does experience pressure differences that draw air in and out of a building, similar to that of the pressure difference caused by the upper atmosphere on an airplane. Most residential construction in the US does not utilize an air barrier under the foundation, and if an air barrier is installed, it is done in a piecemeal fashion. An air barrier below the foundation is necessary, as a surprising amount of air can be drawn into the building through the soils. This is a particular concern in Maine because of radon, a poisonous gas that can pollute the air infiltrating through the foundation. 
When installing the air barrier under the foundation, it is important to remove any debris that might puncture the air barrier from below and then continue to protect the air barrier through the construction process (as it is made of plastic). There are other material options for air barriers, but plastic is moisture resistant, flexible and easy to install under the foundation. In addition, it is important to have a flexible material since the air barrier will be installed under the concrete slab, and then continue up the foundation and attach to the wall panels—unlike traditional construction that discontinues the air barrier under the foundation. We have also taken special care to ensure the continuity of the air barrier, including double caulk lines and tape at all joints. 
You can read more blog posts about the GO Home here.
