Building My Net Zero Energy Home: Foundation Details for Airtight Design

http://www.motherearthnews.com/green-homes/building-my-net-zero-energy-home-foundation-details-for-airtight-design.aspx

 

Finish foundation. Notice that the top surface of the wall has been leveled and hard troweled so it is smooth. This helps create a tighter fit between the sill plate and the concrete to reduce infiltration and exfiltration – air movement in and out of a house.  Be sure to install sill seal foam beneath the sill plate for a very tight fit.

The photo below shows a close up of the top of the wall. Notice the two J bolts – one for the exterior 2 x 4 wall, the other for the interior 2 x 4 wall. As I noted in an earlier blog, I decided to build double 2 x 4 walls because it was considerably cheaper than ICFs and structural insulated panels. I am also very familiar with this technique, having used it to energy retrofit my 2,400 square-foot classroom building.  I would have liked to have used straw bales, but they are strictly forbidden in my county thanks to the fire commissioner’s wariness.


Contributing editor Dan Chiras is a renewable energy and green homes expert who has spent a lifetime learning life’s lessons, which he shares in his popular blog, Dan Chiras on Loving Life. He’s the founder and director of The Evergreen Institute and president of Sustainable Systems Design. Contact him by visiting his website or finding him on .