Retaining Wall Permits in Calgary: When You Need One

When does a retaining wall need a permit?

According to the City of Calgary, a building permit is typically required when:

• A wall retains 1.2 m (4 ft) or more of soil.
• Walls or garden boxes within 1 m (3 ft 3 in) of each other are combined — if their total height is 1.2 m or more, a permit is typically required even if no single wall reaches that height on its own.

Most low terraced walls in a flower bed or along a driveway stay under this limit. Taller walls, or a series of stepped walls close together, are the ones that need a permit — and the City notes walls at or above 1.2 m may also need a development permit, so confirm for your property before you build.

Walls next to a fence or gate

A retaining wall often sits right below a backyard fence on a sloped lot. The fence has its own height rule on top of the wall: a permit is typically required for a fence higher than 2 m (6 ft 6 in) in the rear yard, measured the same way as any other fence. If the wall adds height to the yard before the fence even starts, plan the two together so the combined structure still meets both rules.

Why drainage matters more than height

A wall that fails almost never fails because it was too tall — it fails because water built up behind it. Backfilling with free-draining gravel, adding weep holes or a drain pipe behind the wall, and sloping the soil surface away from the wall all reduce the pressure that Calgary’s freeze-thaw cycles put on a wall every winter and spring.

Choosing a wall material

Common options for Calgary yards:

• Interlocking block: engineered for retaining use, widely available, and straightforward to build in curves and steps.
• Natural stone: a higher-end look that blends into garden beds, usually built dry-stacked or mortared.
• Timber: lower cost for short walls, but has a shorter lifespan in our climate than block or stone.

Before you build

• Request utility locates through Utility Safety Partners (Click Before You Dig) before excavating for footings or a drain line.
• Check your Real Property Report so the wall stays on your side of the property line.
• Plan the whole slope, not just the wall — grading above and below it affects how well it drains.

How Josan Construction & Landscaping can help

We design and build retaining walls across Calgary, Airdrie, Chestermere, Cochrane and Okotoks, with proper drainage behind every wall. Estimates are free, and our team speaks English, Hindi, Punjabi and Urdu.

Sources

• City of Calgary – Fences & retaining walls
• Utility Safety Partners – Click Before You Dig (homeowners)

Sources checked October 17, 2026. City guidance changes and has no legal status — always confirm requirements with the City of Calgary for your property.