Recommended levels of insulation for new and existing homes by climate zone

Alex Wilson, founder of Building Green, Inc. and executive director of Environmental Building News, knows insulation. In fact he wrote the book on insulation. In a recent post at Green Building Advisor, he offers some recommendations for residential insulation.

Apparently Wilson gets asked often about how much insulation is enough. To answer the question, he breaks it down by region. If you are trying to achieve a high performance building envelope, Wilson’s guidance is invaluable.

It depends to a significant extent on where you live. And it depends on whether we’re talking about a new house or trying to squeeze insulation into an existing house.

To simplify the discussion, let’s assume, for the time being, that we’re talking about new construction

As for location, I’ll provide recommendations for three different climates, based on the U.S. Department of Energy (DOE) and International Energy Conservation Code (IECC) climate zones.