[Editor's note: Roger and Lynn Normand are building a [no-glossary]Passivhaus[/no-glossary] in Maine. This is the 21st article in a series that will follow their project from planning through construction.]
Superinsulation is the most effective weapon we have against wintertime heat losses. R-values of 60 or more in the roof and 40 in exterior walls can slow the movement of heat to a crawl, keeping energy costs far below what they’d be in a conventionally built house.
Yet Harry Seidel puts his finger on a potential problem. During the summer, any heat generated inside the house will have just as much trouble getting out of the house.