Beautifying your backyard: Gazebo, pergola and trellis

The grass is green, the trees are budding with leaves and the days are getting noticeably longer. Home improvement magazines and stores are advertising the many options for lawn and garden projects to make your backyard a beautiful place to relax and entertain. If you are considering beautifying your backyard with a garden project such as a gazebo, pergola or trellis, here are some important tips and information to know when deciding which project is best for you.

Some garden projects, including the following examples, do not require a permit. Independent structures less than 10 sq. m. (approx. 107 sq. ft.) in area, for example:

- 6 ft. x 3 ft. decorative pergola entrance feature
- Planting trellis’ for climbing vines or garden shade
- 10 ft. x 10 ft. covered gazebo
- Pergola style garden swing

When do I require a permit?

Structures greater than 10 m² in area, those built on top of another structure, or attached to an existing roof, all require a building permit. This is for reasons of safety, as well as to ensure structural stability, prevent damage to existing structures and confirm compliance with the Land Use Bylaw. A development permit may be required if the structure does not follow Land Use Bylaw rules. Visit calgary.ca/myhome for more information.

The following projects are some examples of when a building permit is required:

Structures located on an existing or new deck

- A pergola located on top of a deck must be supported by this structure. This includes the weight of the new construction, as well as the additional snow load that is typical in southern Alberta.
- If you are building on top of existing construction, additional posts and piles could be required to support the new load.
- If you are building both the deck and the pergola at the same time you may need to increase the size or number of supporting members.

Structures tying into an existing roof

- Tying structural members into an existing roof requires verification that the construction will meet current building code requirements.
- Any connection into existing construction must ensure that the integrity of the roof and building envelope will not be compromised or allow the migration of moisture into the home.
- Be aware that not all products available through your local home improvement store were made for use in Canada; when you apply for a building permit you may be asked for documentation on the product testing.

Independent structures greater than 10 sq. m. (approx. 107 sq. ft.) in area

- Larger gazebos or pergolas follow the same requirements as detached garages. These structures require anchoring to prevent wind uplift. This may be achieved with piles or securing it to a poured concrete slab.
- Eaves are not permitted to be any closer than 0.45 metres (about 18 inches) to the side of the property line.
- Some designs, specifically open styles in higher elevations or areas with significant wind, may require cross bracing for added rigidity.
- The Alberta Building Code includes minimum sizes and standards for the construction of wood frame structures. If you are purchasing a ready-built structure, larger than 10 sq. m., of metal or other construction, additional information will be required. In these cases you will require manufacturer’s literature and confirmation of a listing in the CCMC Registry of Product Evaluations to indicate that the product has been tested for use in Canada. If this documentation is not available you will require independent verification from a structural engineer registered to practice in the province of Alberta. Since an engineer review can add significant costs to your project it is important to ask these questions before you purchase.

For projects that require a building permit, the following drawings are required:

Site plan

A bird’s-eye view drawing of your property that shows the location and dimensions of the structure you are proposing to build.

Floor plan

A top down view including the dimensions of the structure and all labelling of the structural components (number and spacing) required to build it.

Cross section

A section cut through the structure itself, which labels the components and relative position of all items required to build.

Detailed brochures, descriptions and pictures of permit requirements are available both online at calgary.ca and in-person at the municipal building (800 Macleod Trail S.E.). Additionally, the Planning Services Call Centre is available to answer your building questions at 403-268-5311, Monday to Friday 8:00 a.m. to 4:15 p.m.