What makes Alberta different
Plenty of places get colder than Calgary. Very few cycle the way it does. A chinook can lift temperatures 25 or 30 °C within a day and drop them back overnight, and that repeated movement across the freeze point is harder on a building than sustained cold would be.
The practical consequences are specific: snow melts and refreezes at roof edges building ice dams, meltwater runs to foundations and refreezes in downspouts and window wells, materials expand and contract repeatedly, and a property can go through the freeze-thaw sequence a dozen times in one winter.
Add sustained winds frequently exceeding 100 km/h on the west side of the city, and multi-day cold snaps below −25 °C, and you have a season that requires actual preparation rather than a thermostat adjustment.
Freeze risk is the whole game
Everything else on this page is secondary to keeping water from freezing inside the building. Either maintain heat, or remove the water. Doing neither is how houses get destroyed.
If you maintain heat, the number most commonly recommended is around 15 °C, and the reason it is not lower is that your thermostat reads one point in the house while the plumbing runs through the coldest parts of it.
If you remove the water, shut off and drain rather than just shutting off. Water left in the lines can still freeze and split a pipe; you simply avoid the continuous flow when it thaws.
- Identify the cold spots in your specific property: exterior walls with plumbing, unheated garages, basements, bathrooms on corners, rooms over unheated space.
- Have those locations checked specifically rather than relying on a single thermostat reading.
- Open cabinet doors under sinks on exterior walls.
- Leave interior doors open and registers open everywhere.
- Confirm the main shut-off actually closes before you rely on it.
The furnace vent problem
High-efficiency furnaces vent through a plastic pipe out a sidewall, usually a metre or two above grade. Snow drifting against the wall, ice building up from a chinook melt, or frost accumulating at the termination will block it, and the furnace will shut down on a safety.
This is one of the most common heating failures in Alberta vacant properties and it is entirely mechanical — the furnace is fine, the vent is blocked, and there is nobody to clear it.
It is also the failure most likely to happen at the worst time, because the conditions that cause it — heavy snow, blowing drifts, a chinook melt followed by a hard freeze — are the same conditions in which you most need the furnace running.
Snow, ice and the bylaw
City of Calgary bylaw requires the public sidewalk adjoining a property to be cleared within 24 hours of a snowfall ending. That obligation attaches to the owner and does not pause for absence. The city can arrange removal and bill you, plus a penalty.
Beyond compliance, an uncleared walk is the single clearest signal that a house is empty, and it is a liability if someone is hurt.
The part that usually fails is not booking the service — it is verifying it happened. Owners arrange clearing from another province, receive invoices, and never confirm the walk was actually clear.
- Arrange clearing on a per-snowfall or seasonal basis before you leave.
- Have the result verified and photographed rather than assumed.
- Keep window wells clear of accumulated snow.
- Watch for snow drifting against the foundation, which directs meltwater exactly where you do not want it.
- Observe low-slope roof sections after heavy wet snowfalls, from the ground.
After every chinook
- Roof edges checked from the ground for ice dam formation
- Downspout discharge clear and running away from the foundation
- Ceilings near exterior walls checked for staining
- Window wells clear of ice and meltwater
- Nothing displaced by the wind
- Fencing and gates intact
- Furnace vent terminations clear of ice
- Interior temperature holding
Related questions
Should I shut the water off when I travel?
For an extended absence in an Alberta winter, shutting off the water is the single most effective step available to you. It removes the mechanism for the most expensive thing that happens to vacant homes.
The reasoning is simple. A supply line that fails while the water is on runs continuously at full pressure until someone closes a valve. The same failure with the water off produces nothing. Shutting off does not prevent pipes from freezing, but it dramatically limits what happens when one does.
For it to work properly, shutting off is not enough on its own — the system should also be drained. Open the lowest fixtures to relieve pressure and let standing water out. Water left in the lines can still freeze and split a pipe; you simply avoid the continuous flow afterwards.
Some caveats. If your property has a fire sprinkler system, do not shut off the supply — that system needs to remain charged. If the property has a boiler or in-floor heating, the heating loop is separate from the domestic supply and needs different handling. If the shut-off valve is old, seized or leaking, force it and you may create the problem you were preventing; have a plumber deal with it first.
Also check your policy. Some insurers require water to be shut off and drained during extended absences in the heating season, and some accept maintained heat as an alternative. Which one applies to you is worth knowing before you decide.
What temperature should I leave my house at when I go away?
The most commonly recommended minimum for an unoccupied home in a Canadian winter is around 15 °C, though recommendations range from about 13 °C to 18 °C. Some insurance policies specify a figure — if yours does, that number governs, not a general recommendation.
The reasoning behind keeping it that high rather than lower: the thermostat reads the air temperature at one location, usually a hallway on the main floor. Temperatures elsewhere in the building — exterior walls, the basement, above the garage, in a bathroom on a corner — run meaningfully colder. Setting 15 °C at the thermostat may mean 8 °C or lower where the plumbing actually is.
Setting it much lower to save on heating is a poor trade. The savings over a winter are modest; the cost of a single burst supply line is not.
A few practical points. Leave interior doors open so heat circulates. Open cabinet doors under sinks on exterior walls. Keep registers open in every room, including ones you would normally close off. If the property has a smart thermostat, set a floor rather than a schedule, and check that any away mode does not drop below your intended minimum.
And ask your insurer whether your policy specifies a minimum temperature during absences. Several do.
Do chinooks cause problems for vacant properties?
Yes, and they are underrated as a risk precisely because they feel like relief.
A chinook can raise temperatures 20 to 30 °C within a day, then drop them back overnight. That cycling is harder on a building than steady cold. Snow melts and refreezes, building ice dams at roof edges. Meltwater runs toward foundations and refreezes in downspouts and window wells. Materials expand and contract repeatedly.
Chinooks also bring strong wind — sustained speeds regularly exceeding 100 km/h in west and southwest Calgary and in the foothills. That produces roofing damage, displaced outdoor items, and wind-driven water intrusion at windows and wall junctions.
The practical response is to check the property after chinook events rather than only on a fixed schedule: look at roof edges for ice dam formation, confirm downspout discharge is clear and running away from the foundation, check ceilings near exterior walls for the first signs of intrusion, and confirm nothing has been displaced by the wind.
Do I still have to clear snow if nobody lives there?
Yes. City of Calgary bylaw requires the public sidewalk adjoining a property to be cleared of snow and ice within 24 hours of a snowfall ending. That obligation attaches to the property owner and does not pause because the property is empty or the owner is out of the country.
Failure to clear can result in the city arranging removal and billing the owner, plus a penalty. More practically, an uncleared walk in front of an obviously empty house is a liability if someone is injured, and it is one of the clearest possible signals that nobody has been there.
Arranging clearing is straightforward; the part that fails is verification. Owners commonly book a service from another province, receive invoices, and never confirm the work was actually done. Having someone confirm and photograph the result after each snowfall closes that loop.