Spray Foam Insulation in Wetaskiwin, AB.

The second axis is where Wetaskiwin separates from its neighbours. At 58.2% single-detached it has one of the lowest shares in this ledger — roughly two in five dwellings are attached, stacked or otherwise not a house on its own lot.

Old plus attached is the combination that produces the most persistent complaints. In a pre-1980 multi-unit building the air barrier was rarely conceived as one continuous surface around each suite, so warm air migrates through party-wall cavities and shared attic space until it reaches something cold. The unit that feels the draught is frequently not the unit with the defect, which is why these buildings resist unit-by-unit fixes and reward a whole-building approach to the attic plane and the perimeter.

Wetaskiwin has no station of its own. Its figures are borrowed from CAMROSE (climate ID 3011240), about 45 km east: 5,634 heating degree days at an 18 °C base, a -17.8 °C average January daily minimum, and -44.9 °C at the extreme — the coldest recorded January of the five stations used across these 27 communities.

Camrose reads that same station from within its own city limits, so the identical figures on the two pages reflect one shared source. Note also that Wetaskiwin sits west of the station, nearer the QEII corridor than the station is.

The County of Wetaskiwin No. 10 extends northwest toward the Pigeon Lake recreational area. Lake-country buildings in Central Alberta tend to be the ones heated intermittently, and an intermittently heated envelope crosses the dew point far more often than a continuously occupied one — which puts the emphasis on an unbroken air and vapour seal at rim joists, crawl spaces and roof-wall junctions rather than on insulation depth.