Edmonton's new construction is weighted towards infill and towards housing with a secondary suite in it, and both of those change what the insulation is being asked to do. Spray foam insulation for new construction in Edmonton is often about separations inside the building rather than the outside wall.
A suite makes interior assemblies into envelope
Put a legal suite in a new house and the floor between the two units, and the wall beside the stair, stop being ordinary interior assemblies. They now separate two households, and they carry requirements around sound and fire that an interior wall does not. They are also where the occupants notice quality most directly, because they hear each other through them.
Infill lots are tight and that changes the sequence
A skinny lot with neighbours a few feet away restricts scaffolding, deliveries and where anything can be staged. Work that happens from the inside is easier to schedule on those sites than work that needs the exterior to be accessible for long. It is a practical reason infill builders in this city look at what can be done within the frame.
Party walls and the two-house-in-one lot
Duplex and semi-detached infill puts a shared wall down the middle of the build. That assembly has to perform for sound and separation while the two halves are often sold to unrelated owners who will never coordinate on maintenance. It is worth building it once, properly, because nobody will ever open it again.
A long heating season rewards the envelope more here
Edmonton runs a longer heating season than the south of the province, so the difference between an adequate envelope and a good one accrues over more months every year. On a new build that is the whole argument: the cost is one-time and paid at the cheapest possible moment, and the difference is collected every winter the building stands.
The rim joist is easiest now and hardest later
The band where each floor lands on the wall is fully open during framing and largely buried afterwards. Treating it while the building is open costs very little on top of the wall work and removes what is usually the largest air path in a finished house.
Spray Foam Insulation New Construction Edmonton: Common Questions
Does a secondary suite change the insulation requirements? It changes what the interior assemblies are for. The floor and stair wall between units now separate two households and carry sound and separation requirements an ordinary interior wall does not.
Why does infill favour work done from inside? Because the lot is tight. Scaffolding, staging and prolonged exterior access are all harder on a skinny lot with close neighbours, so approaches that work within the frame schedule more easily.
Is a longer winter an argument for spending more at build? It is. The cost is one-time and paid at the cheapest point in the building's life, while the benefit is collected every heating season, and here that season is long.
Work out the assemblies with the R-value calculator, then get a free Edmonton quote. More on Spray Foam Insulation New Construction Alberta.