I’ve been writing about residential energy-efficiency measures for more than 25 years, ever since I was hired as an assistant editor at the Journal of Light Construction in 1999. Recently I wondered, “What’s changed during those 25 years?” The answer, as it turns out, is “a lot.”

My conclusion contradicts a recurrent theme in newspaper stories on U.S. residential construction—namely, that our industry is stuck in the mud, still building houses the old-fashioned way. (A recent example of this theme was published by the New York Times: “Why Do We Build Houses in the Same Way That We Did 125 Years Ago?”) The authors of these articles often point out, accurately, that most U.S. homes aren’t delivered by truck from a factory; instead, they are mostly site-built out of framing lumber, much as they were in 1960.

But if you are one of a subset of builders or homeowners who cares about energy efficiency and environmental responsibility, you’ll find that the specifications for a home in 2024 are much different than they were in 1999.

Some things have stayed the same

Some specifications for energy-efficient construction haven’t changed much. For example, back in 1999, many New England builders were building extra-thick walls to accommodate more insulation; installing a thick layer of cellulose insulation on attic floors; choosing among various brands of triple-glazed windows; getting ready for a blower door test by performing air-sealing work; and specifying the installation of a heat-recovery ventilator. For energy-conscious builders in cold climates, these details remain common today.

However, many residential specifications that are now routine didn’t exist back in 1999.

A glance back at America’s first zero-energy house

Since zero-energy homes are now quite common, it’s easy to forget that the first zero-energy home in the U.S.—that is, the first house to demonstrate…