For nearly a century, building codes had a singular focus: keep the building standing and keep the fire out. If the house was drafty or expensive to heat, that was considered a personal problem for the homeowner, not a matter of public policy.

That changed in 1973.

The oil embargo wake-up call

When the OPEC oil embargo hit, the cost of heating American homes skyrocketed. Suddenly, energy wasn’t just a commodity; it was a matter of national security. For the first time, policymakers realized that our buildings were “sieves,” leaking massive amounts of energy through thin, uninsulated walls and single-pane windows.

This birthed the International Energy Conservation Code (IECC). For the first time, the law didn’t just care if your house was safe; it cared how much insulation was in your attic and walls.

From ‘should’ to ‘must’

Early energy codes were often suggestions rather than requirements. However, as our understanding of climate change grew, the energy code became the fastest-changing part of the building code. We moved from simple fiberglass batts in the walls to requiring “continuous insulation”—a “sweater” for the house that prevents heat from escaping through the wooden studs themselves.

The invisible benefit

Today’s energy codes do more than save money; they protect the building itself. A well-insulated, airtight and properly ventilated building keeps moisture out of the wall cavities, preventing the mold and rot that plagued older homes (more about this in the next Sustainability section). While the safety code protects you from a fire that hopefully will not occur, the “Energy Code” protects your health and your wallet every single day.