Wall spray foam insulation in Carstairs is work on houses built recently enough that the walls were insulated properly when they went up, which means the useful question here is not depth but continuity.
Built to a standard, and still losing air at the joints
A wall in a newer Carstairs house has batt in the cavity at a specified value and there is usually nothing wrong with it. What was rarely done to the same standard is the sealing: the joint between the wall and the floor structure, the gaps around window and door openings, the penetrations for services, and the junction where the wall meets the ceiling. Those are air paths rather than insulation deficiencies, and they behave differently. They matter most in a house that is set back all day and has to recover in the evening.
Why a house of this age can still feel draughty
The household experience is a cold spot near an outside wall, a draught at an outlet on a windy day, or a room that never quite matches the rest. In a properly insulated wall those are almost always leakage rather than a lack of material, which is why adding to the cavity would not fix them and why the diagnosis matters more than the product. This is a different starting point from an older town and it deserves saying rather than assuming.
When the wall is worth opening at all
Being straight about this: on a house of this vintage, the wall is usually not where the money should go. The attic, the rim joist and the basement band deliver more for less, and the wall belongs to a moment when it is open anyway, such as a re-side or a room being taken back to studs for other reasons. An owner in Carstairs is generally better advised to wait for that moment than to manufacture it.
The cases where it genuinely is the wall
There are exceptions and they are worth naming. A bonus room or a cantilevered section with an exterior wall exposed on more than one side, an addition built to a different standard from the original house, and a wall that has been opened after water damage are all situations where treating the wall properly is the right call. In each of those the wall is either unusually exposed or already accessible, which is what changes the arithmetic. Outside those, the money goes further almost anywhere else on the building, and an honest quote should say so rather than pricing the walls because they were what got asked about.
Wall Spray Foam Insulation Carstairs: Common Questions
Is spray foam worth it if the wall already has insulation in it? Usually yes. The problem in a house this age is normally air leakage, not depth.
Should we add to the cavity? Rarely worth it on its own. Sealing the joints is what changes how the room feels.
When is wall work justified? When the wall is open anyway, or on an addition or exposed section built differently.
Size the assembly with the R-value calculator, then get a free Carstairs quote. More on Wall Spray Foam Insulation Alberta.