Spray Foam Insulation in Stettler, AB.

67.5% single-detached puts Stettler in the middle of the range — roughly a third of dwellings share a wall, floor or roof with another unit, which for a town of this age means older attached stock rather than new townhouse development.

Older attached buildings are where heat loss is hardest to attribute. Warm air moves between suites through party-wall cavities, shared attic space and common chases, so the coldest unit in a fourplex is often cold because of an unsealed penetration in a neighbouring one. With 1,430 dwellings on the pre-1980 side of the ledger and a declining population, the practical question is which buildings justify a full envelope intervention and which justify only the attic plane.

Stettler is assigned CORONATION CLIMATE (climate ID 3011887). The ledger records no distance from the town to that station, and does not estimate one — so the figures below carry an unquantified geographic gap: 5,887 heating degree days at an 18 °C base, an average January daily minimum of -18.8 °C, -43.8 °C at the extreme.

Those numbers are identical to Hanna's, 267 degree days above the Red Deer reading most of this corridor uses. The identity with Hanna is not a similarity between the two towns — it is the same Coronation station being read twice.

The preserved Parrish & Heimbecker grain elevator is the last standing of three that once operated in Stettler. Wooden grain elevators are a specific and difficult building type to condition: a tall, single-volume timber-cribbed structure with almost no cavity to insulate and an enormous surface-to-floor-area ratio. Preservation projects on them are envelope projects.