Spray Foam Insulation in Leduc, AB.

63.2% single-detached is moderate for a city of 34,094, so Leduc carries a substantial share of attached and multi-unit stock alongside its houses — much of it built during the growth phase rather than before it.

The result is two distinct populations of building in one city. The 3,448 pre-1980 dwellings mostly need what older stock everywhere needs: a continuous air barrier at the attic plane and the rim joist, which was not standard practice when they were framed. The roughly 9,516 newer ones usually have that barrier and instead have specific gaps in it — attached garages, bonus rooms over unheated space, cantilevers, and mechanical penetrations in a party wall.

Leduc's figures come from EDMONTON INT'L A (climate ID 3012205), about 5 km away — one of the shortest borrows in this ledger, but a borrow all the same: 5,697 heating degree days at an 18 °C base, an average January daily minimum of -18.1 °C, -44.4 °C at the extreme. Leduc, Nisku and Beaumont all read this station, so their winter figures are identical to each other by construction.

Leduc's industrial position is the reason to look at it at all. The Leduc Business Park and the adjoining Nisku Business Park are together billed as the second-largest energy manufacturing industrial park in North America and the largest in Canada, sitting on the CANAMEX trade corridor (leduccountybusiness.com).

Energy-services manufacturing buildings are not warehouses. They combine high-bay fabrication space with frequent large door openings, process heat in some bays and none in others, and mezzanine offices sharing an envelope with an unconditioned shop floor. Those are conditions where a continuous air seal on the shell matters more than the nominal insulation value in any one assembly.