Many years ago, I was partnered up with an old-school developer. We were spec-building vinyl-sided houses in N.J. My partner, like too many builders today, didn’t really understand how the bits and pieces of home energy performance fit together. He was confident that code-level insulation was enough, had no truck with air-sealing, and thought low-e glass was a waste of money. My understanding of those issues wasn’t much better, but at least I knew there was a lot I didn’t know.

One cold winter day, we watched a mason across the street working on an exterior chimney. He had pipe staging erected to 30 ft. in the air. It was wrapped in plastic from the ground up and over the top; and he was running a kerosene heater inside to keep him and his materials from freezing.

My partner scoffed: “What does he think the R-value of 6-mil poly is?”

Well, I thought, not much. But clearly that poly does make a difference.

His question spurred an epiphany on my part. It was obvious that the poly would be holding in a great deal of the kerosene heater’s warmth—as well as its fumes. Would I rather be outside the poly in the 10℉ air, or inside where the temps would have been well above the freezing mark?

Shivering in the cold, I knew the answer intuitively. It was the first time that the importance of an air barrier—a term I did not yet know—struck home.

Outdoor clothing

Even before that moment, I’d begun to realize the importance of keeping out the wind. In my 20s, I’d dabbled in winter camping, hiking, and skiing. It didn’t take long to understand that if the wind could get past my outer layer, even the puffiest inner layers…