Not So Passiv Haus

Credit: Garen Meguerian

We've spent thousands heating our house, and now I learn some people in Canada and Germany have zero heating bills! And they've had this technology for decades. High performance houses are built with foot-thick exterior walls. They're so sealed and insulated you could heat them with a hairdryer.

Buildings Account for 39% of CO2 emissions in the United States, and most of this is heating and cooling. Material costs and their durability count too - folks are looking for a five-year payback on their investment.

In new construction it's possible to use structural insulated panels (SIPs) and double-stud walls. Sealed on the inside with spray foam, and designed with the right windows, a passive house can be heated with sunshine only.

Our house was built in the '60s, and some of these thin walls have no insulation. We've insulated the floor. The windows face east and we're shaded on the south - sadly, this nearly eliminates solar gain and light in the winter.

Existing construction may be stuck with the stud-walls it already has, but it's possible to retrofit additional insulation with new exterior siding and roofing. Wrapping the house in 2" rigid foam might half our heating bill, also improve comfort and moisture handling.

Some building systems last a few decades before they need to be repaired - rule-of-thumb is to budget one-percent/year for home maintenance. What's the new hotness now that it's time to replace the roof?

You'd think there would be some amazing new tech every decade, but building performance moves in geological time, almost imperceptibly. Fixing the house would be less of a pain if there was advanced stuff. It kills me to replace sixty-year-old crap with essentially the same crap.

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