All through the 1980s and 1990s, a small band of North American believers worked to maintain and expand our understanding of residential energy efficiency. These were the pioneers of the home performance field: blower-door experts, weatherization contractors, and “house as a system” trainers. At conferences like Affordable Comfort, they gathered to share their knowledge and lick their wounds.
These pioneers understood what was wrong with American houses: They leaked air; they were inadequately insulated; they had bad windows; and their duct systems were a disaster.
Occasionally, these energy nerds would scoff at millionaire clients who were more interested in “green bling” — a phrase that usually described photovoltaic panels — than they were in reducing air leaks in their home’s thermal envelope.
What I’ve just described is (in anthropological terms) a set of beliefs associated with a distinct subculture. Our tribe had a shared belief: that improving a home’s thermal envelope is preferable to installing renewable energy equipment.
Occasionally, a few facts would appear to undermine our belief system. For example, if a disinterested observer noted that a proposed envelope measure had a very long payback period, most members of our tribe would answer that the measure was a wise investment, because energy prices are likely to skyrocket in the future.
During the waning years of the last millennium, these North American beliefs crossed the Atlantic and were adopted by a group of academics in Darmstadt, Germany.
The beliefs became petrified in a set of rules called the Passivhaus standard.
Several factors have changed since these beliefs were first formulated. For one thing, fossil fuel prices have stayed low; for another, photovoltaic equipment has gotten dirt cheap.
The (sometimes painful) fact is that it is now hard to justify many energy-retrofit measures that energy experts still eagerly recommend. Moreover,…