What is the frost depth in Alberta?

There is no single frost depth for Alberta, and any source giving you one number for the whole province is oversimplifying. Frost penetration varies by location, soil type, drainage, snow cover and whether there is heated space above the foundation. The building code reflects this: it requires foundations to extend below the depth of frost penetration rather than naming a fixed provincial figure. For a specific site, confirm the required depth with your municipality's building department or a local geotechnical engineer.

How deep do footings have to be in Alberta?

Deep enough to be below the depth of frost penetration for that site, or otherwise protected against frost movement. The National Building Code's minimum depth of foundations table sets requirements by soil type and by whether there is heated space above — for some combinations it states a numeric minimum, and in every case it also requires the footing to be no shallower than actual frost penetration. Alberta uses the National Building Code – 2023 Alberta Edition, so the exact table in that edition governs. Your municipal building department applies it.

Why do I get different answers about frost depth from different people?

Because they are often answering different questions. A number quoted for a heated house foundation does not apply to an unheated garage. A depth that works in well-drained gravel can be inadequate in clay. Someone may be quoting a rule of thumb, a municipal practice, a code minimum, or what they personally dug last week. All four can be different and none is automatically wrong — they just are not interchangeable.

Does frost heave only affect shallow foundations?

Shallow and unheated foundations are the most vulnerable, which is why cabins, garages, decks and outbuildings heave most often. But a deep foundation is not automatically safe. Frost can grip the sides of a foundation wall and lift it — adfreezing — and poor drainage can cause problems at any depth. Depth is one defence among several; drainage and soil conditions matter alongside it.

Do I need a permit for foundation repair in Alberta?

Often yes, but it depends on the municipality and on the scope of the work. Structural work generally falls under the Safety Codes Act and is administered by your municipality or its accredited agency. Requirements differ between, say, the City of Edmonton and a rural county, and they change over time. Contact your local building department before work starts — that is the only answer specific to your project, and it is free to ask.

Can a foundation be built above the frost line?

There are engineered approaches — frost-protected shallow foundations use insulation to raise the frost line around a heated building rather than digging below it. They are a recognised technique, but they are an engineered design, not a shortcut, and they have specific conditions attached. If someone proposes building shallow without an engineered frost protection design, ask what standard they are working to.

Alberta Reference Guide

Frost Depth & Foundation Requirements in Alberta

There is no single frost depth for Alberta. What the building code actually requires, what changes frost penetration from one site to the next, and how to find the figure that applies to your property.

Last reviewed August 30, 2026

The Short Answer

There is no single frost depth for Alberta. The building code does not publish one, and neither does the province. If a website gives you one number for the whole province, it is guessing.

What the code requires instead is that a foundation extends below the depth of frost penetration for that particular site — or that it is protected against frost movement by some other engineered means. The required depth is a local question, and the answer changes with soil, drainage, snow cover and whether the space above is heated.

For a specific property, the figure that matters comes from your municipal building department or a local geotechnical engineer. Everything below explains why that is the case, and what to ask them.

What the Building Code Actually Says

Alberta uses the National Building Code – 2023 Alberta Edition, which came into force on May 1, 2024. It is the national code with Alberta-specific amendments, and it is administered locally through the Safety Codes Act.

The relevant part is the section on minimum depth of foundations, numbered 9.12.2.2 in the National Building Code family. Rather than naming a depth for each region, it sets requirements by soil type and by whether there is heated space above the foundation. For some combinations it gives a numeric minimum; for others it simply requires the footing to sit below the depth of frost penetration. And where a number is given, it comes with the same condition attached — the footing must still be no shallower than actual frost penetration at that site.

Read the real table, not a summary

We have deliberately not reproduced the code's depth table here. The values depend on soil classification and drainage conditions in ways that a simplified web table loses, and the edition in force can change. Work from the Alberta edition itself, or from what your building department tells you. Both are linked in the sources below.

One practical consequence worth knowing: the Alberta edition is published by the National Research Council rather than posted free by the province. British Columbia publishes its equivalent code openly, which is useful for understanding how the section is structured — but it is the Alberta edition that governs work in Alberta.

Four Things That Change Frost Depth on Your Lot

Two properties on the same street can need different footing depths. Here is why.

Soil type

Coarse, well-drained gravel behaves very differently from clay or silt. Fine-grained soils hold water, and water is what does the damage when it freezes. This is why the building code's own depth table is organised by soil type rather than by town.

Moisture and drainage

Frost heave needs water. A well-drained footing in dry ground can sit through a cold winter with little movement, while a saturated one a block away lifts. Drainage is often the single biggest variable on a given lot — and the one most within your control.

Snow cover

Snow insulates. Ground that stays blanketed all winter freezes shallower than ground scraped bare by wind or by a plough. A driveway edge, a shovelled path and an untouched lawn on the same property can freeze to noticeably different depths.

Heated space above

A heated basement warms the soil beneath the building. This is why the code sets different requirements for foundations with heated space above them and those without — and why unheated structures like garages, decks, cabins and outbuildings are the ones that heave.

Why This Matters When Something Has Already Moved

Most of the structures we get called to were not built to any of this. Cabins on timber cribs, garages on cinder blocks, additions on footings poured a foot down because that was what the ground allowed on the day. They worked for years, and then a wet autumn followed by a hard winter moved them.

When a structure has heaved rather than settled, lifting it back to level without addressing the cause is temporary. The frost that moved it once will move it again. That is why a proper repair deals with three things together: getting the bearing below frost penetration or engineering around it, fixing the drainage that saturated the soil in the first place, and using footings that can be adjusted if the ground has more to say.

If you are trying to work out whether your structure has settled or heaved — they look similar and need different fixes — our page on the science of stability covers how to tell the difference, and cabin leveling walks through what a lift and re-support actually involves.

Permits for Foundation Work

Structural work in Alberta falls under the Safety Codes Act, administered by municipalities and accredited agencies rather than by the province directly. In practice that means the answer to "do I need a permit" depends on where you are and what you are doing.

We are not going to guess on your behalf

Permit requirements differ between neighbouring municipalities and they change. A contractor's website is the wrong place to get a definitive answer, and getting it wrong is expensive. Call your local building department before work starts — the call is free and they will tell you exactly what applies.

Useful things to have ready when you call:

The legal land description or municipal address
What the structure is — dwelling, garage, cabin, addition, outbuilding
Whether there is heated space above the foundation
What you are proposing — levelling, underpinning, new piles, full rebuild
Whether an engineer has been involved yet

We handle permit coordination on the jobs we take on, and we will tell you plainly if a job needs an engineer's involvement before we touch it.

Frost Depth — Common Questions

Sources

Every factual claim on this page traces back to one of these. Check them yourself.

Alberta.ca — Building codes and standards
Which code edition is currently in force in Alberta.
Safety Codes Council — 2023 Alberta Edition code updates
Announcement and background on the current Alberta code edition.
NRC — National Building Code, 2023 Alberta Edition
The code itself, published by the National Research Council.
Section 9.12 Excavation — minimum depth of foundations
Freely readable version of the equivalent National Building Code section, published by British Columbia. Useful for understanding how the depth table is structured; the Alberta edition governs in Alberta.
City of Edmonton — application requirements for house permits
Example of one municipality’s permit requirements.
Strathcona County — residential permits
Example of a neighbouring authority with its own process.

This page is general information, not engineering advice for your building. Frost penetration, soil conditions and code requirements vary by site, and only a site assessment can establish what a specific structure needs. Code editions and municipal requirements also change — if you are reading this well after August 30, 2026, confirm the current edition before relying on anything here.

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