Building a secondary suite in the City of Calgary can be a challenge. There’s a number of requirements that your home must meet to be legally rented. These regulations are meant to provide a safe living space for your tenants and to ensure that they have a separate dwelling unit. There are also permits and consultation processes to consider since adding a basement suite or downstairs apartment will impact your neighbours.

All of this complexity means that you should be aware of added costs before you decide to build. Roughly half of Calgary contractors refuse to build basement suites because of the cost and complexity. We do build secondary suites because we have the experience needed to navigate that process and make it as painless as possible for everyone involved.
We put together this article on legalizing secondary suites in suburban Calgary to give you an idea of what to expect if you renovate your home to upgrade an existing suite.
What is a secondary suite?
The City of Calgary defines a secondary suite as self-contained residence that has at least two rooms as well as a kitchen, sleeping areas (i.e., bedrooms), and sanitation facilities (i.e., bathrooms). These can be built as part of your existing structures such as in a basement or above a garage. They can also be free-standing buildings such as a garden suites or a mother-in-law suite. The later are known as backyard suites.
Do I have an existing suite?
If your home already has a separate area that includes the following, then it can be considered an existing suite:
It was built before 2018
It has a bathroom, cooking facilities and living areas
You can access those without passing through the primary dwelling unit
And it is located in the same building as the main residence (i.e., is not built on a detached garage or as a separate building)
I’m not sure if my existing suite is legal. What do I need to do to legalize a basement suite?
The City of Calgary has a secondary suite amnesty program that extends until 2026. If your existing suite meets the criteria above, then you’re eligible to take advantage of it. You’ll also need to upgrade certain parts of your home so that they meet new building code requirements. Here’s some of the key things the City requires for legalizing a secondary suite:
Add drywall to your furnace/mechanical room
Smoke-tight barriers for shared stairways and hallways
Ensure there’s an appropriate entrance to the suite itself
Make sure there are egress windows for your basement
Add hardwired smoke detectors with at least one interconnection to the main residence
The amnesty program means that existing secondary suites are exempted from some of the more onerous requirements of the new code. They must only meet basic safety code requirements.
What kind of permits are required to legalize an existing secondary suite in Calgary?
There’s a few pieces of paper that you’ll need to do this. You’ll need to apply for a permit regardless of whether or not you are renting your suite (we’ll do that for you as part of our process).
Your application will also need you to include the following forms and declarations (again, we’ll do this for you):
A completed Owner Declaration
A completed Existing Secondary Suite Information Sheet
Colour photographs of the suite’s entryway, parking, bathroom, outdoor amenities, mechanical room/furnace area, each bedroom window
A site plan
A copy of your floor plans
You may also need additional permits for your plumbing and electrical work if you are doing upgrades to those.
How do I know if my suite is illegal?
If your existing suite doesn’t meet the conditions above, lacks a second furnace, or is insufficiently separated from the rest of your living space, then it’s most likely illegal. Your existing suite may also be considered illegal if it is built in a suburb that isn’t zoned for them (Note: Calgary updated its zoning in June of 2024. Stay tuned for our post on the new rules).
You can use the City of Calgary’s Secondary Suite Registry to see if yours has been previously approved and meets the Alberta Safety Code requirements. If you really want to get into the details, you should review Building Advisory A19-003 and Part 9 of the National Building Code – 2019 Alberta Edition. We promise that it’s really riveting stuff…
Why would anyone build a secondary suite? Is it worth the trouble?
While there’s no denying that it can be a complicated process, there’s a number of benefits to building a secondary suite. The biggest reason to legalize an existing secondary suite is that it saves you quite a bit on costs compared to building a new one. The city estimates that legalizing a suite will cost $20,000 less than it would to construct a new one.
Basement suites also add a number of benefits for suburban homeowners like:
Adding a new source of largely passive income that is reliable and stable
Increasing the property value of your home and improve your ability to qualify for a larger mortgage
Maximize your home’s space to build equity and offset maintenance costs
Provide reassurance to tenants about the quality of their home or offer housing options to family members
Ultimately, adding space to your suburban home can come with a number of benefits but it’s certainly not for the faint of heart. Most people find that it’s beyond what they are comfortable doing themselves. That is why hiring a licensed contractor is the most popular option for people who do legalize their existing basement suite. If you have more questions (and you probably do), we’re happy to help.