Spray Foam Insulation in Hanna, AB.

87.7% of Hanna's dwellings are single-detached, the highest share of the 27 communities studied. Pair that with the 68.2% pre-1980 figure and the picture is unusually uniform: an old, freestanding, one-and-a-half or two-storey house on its own lot, with its own attic, its own crawl space or basement, and its own rim joist.

Uniform stock means the same short list of problems repeats house to house. Loose fill in a vented attic that has settled well below its original depth. Top plates, plumbing stacks and attic hatches that were never sealed, so warm indoor air convects straight into the attic and drops its moisture on the underside of the sheathing. A rim joist that is a piece of batt stuffed against a joist end, or nothing at all. None of these are visible from the street, and in a detached house there is no neighbour's unit to mask them — a heat loss here shows up on this owner's bill.

Hanna's climate numbers come from CORONATION CLIMATE (climate ID 3011887), about 65 km away. Hanna has no station of its own. That reading — 5,887 heating degree days at an 18 °C base, a January daily minimum averaging -18.8 °C, an extreme of -43.8 °C — is the coldest of the five stations used across these 27 communities.

Stettler is quoted the identical figure, for one reason only: Stettler is assigned the same Coronation station. Nothing has been measured in either town. Where the two towns’ climate numbers match, that is the station speaking, not the towns.

Hanna's industrial base is named and specific. The Sheerness Generating Station (TransAlta) converted from coal to natural gas in 2021. The Sheerness coal mine that fed it closed the same year — formerly around 200 workers — and the site has since been repurposed for humalite, a soil-amendment extraction. The town also houses the district office for Alberta's Special Areas administration.

A generating station and a district administrative office are long-lived buildings on long-lived sites, which is a different envelope problem from a subdivision: the shell was built to the standard of its own decade and every improvement since has had to be retrofitted into it.