Spray Foam Insulation in Penhold, AB.

The distinguishing figure in Penhold is not the age of the housing but the shape of it. Apartments make up 3.0% of the stock — the lowest apartment share of any community in this data set — and 68.7% is single-detached. This is a town of houses, near enough exclusively.

A 26.4%-pre-1980, near-all-detached town is a town of individual envelopes: every building has its own attic plane, its own rim joist, its own foundation-to-frame junction, and every heat loss lands on one owner's bill rather than being averaged across a block. The work is per-house diagnosis, and it does not scale the way a row of identical townhouses would.

Penhold is unusual in this ledger: it does not borrow its climate data. RED DEER REGIONAL A — Red Deer Regional Airport — is located here, so the 5,619 heating degree days at an 18 °C base, the -17.6 °C average January daily minimum and the -43.8 °C recorded extreme are measured in the town rather than assigned to it.

The same station is then lent out to 17 other communities in this set, from as near as Blackfalds to as far as 160 km away at Drumheller. When a page in this corridor quotes 5,619 degree days, that reading was taken at Penhold.

Penhold carries an active CP Rail terminal — the "Penhold Rail Lands," a 114-acre site with roughly 92 developable acres zoned Light and Heavy Industrial, part of 741 total developable acres following a recent annexation (JLL listing; townofpenhold.ca). Rail-served industrial land tends to fill with large-span metal shells, where the envelope is a single continuous surface rather than a set of framed cavities.

The town is also the site of the former RCAF/CFB Station Penhold, a WWII British Commonwealth Air Training Plan base. The Harvard Historical Aviation Society stewards 10 acres of the old base (Bomber Command Museum of Canada). Buildings of that vintage and type — hangars, drill halls, service blocks — were never built to hold heat, and adapting one is an envelope project before it is anything else.