Legal Secondary Suite in Calgary: Rules, Costs and Rental Math

A basement suite can turn one property into two homes and a mortgage into a shared expense. But in Calgary, the word “suite” only means something once the City has approved and inspected it. A legal secondary suite in Calgary has the right permits, has passed safety inspections and appears on the City’s Secondary Suite Registry. Anything else is, in plain terms, an illegal suite, no matter how nice the finishing is.

This guide covers what the City requires, what changed with the 2026 zoning decisions, what permits cost, how to check a suite before you buy, and how to run the rental numbers honestly. It is general information for investors and homeowners, not legal, tax or building advice for a specific property.

What makes a legal secondary suite in Calgary

The City of Calgary describes a secondary suite as a self-contained residence with two or more rooms that includes kitchen, living, sleeping and sanitary facilities. It sits inside the main home, usually in the basement, though it can also be on a main or upper floor or above an attached garage. A backyard suite is a different thing: it is a separate building in the yard, often above a detached garage.

According to the City, every secondary suite must have:

• Bedrooms with proper egress windows.
• A separate bathroom.
• Separate cooking facilities.
• An entrance that can be reached from outside without passing through the main home. A shared stairwell is acceptable, but each unit needs its own private entrance.

A suite also has to be approved together with the main home. The City is clear that suites are not separate dwelling units, so they cannot be subdivided or sold on their own.

Once a suite has its permits and passes final inspection, it is added to the Secondary Suite Registry, a public, searchable map of legal and safe suites. The registration stays with the address when the property is sold, and the owner receives a numbered sticker for the suite entrance.

What changed in 2026: zoning and permitted use

If you followed Calgary’s zoning debate, the rules for suites moved around this year. On April 8, 2026, City Council approved a repeal of the 2024 citywide rezoning, and on its rezoning project page the City says most properties returned to their pre-2024 zoning on August 4, 2026.

That repeal would have made secondary suites a discretionary use again in many low-density districts, which means a case-by-case review. Instead, on July 21, 2026, Council approved Bylaw 26P2026, which lists secondary suites as a permitted use in all low-density residential districts. Under a permitted use, a suite that meets every rule in the Land Use Bylaw must be approved, rather than being weighed case by case.

A few other changes matter for investors:

• A property can have a secondary suite or a backyard suite, but no longer both.
• Backyard suites remain discretionary in most districts and permitted in R-G.
• Backyard suites are no longer allowed on properties with semi-detached homes, and they have a parking requirement again.

Even with permitted use, a design that needs a relaxation of the rules, such as parking or suite size, can still require planning approval. The City’s Adding a secondary suite page has an address lookup that tells you whether your parcel needs a development permit. Check that before you pay for drawings.

The building code items that drive cost

Most of the cost and effort of a legal suite comes from life safety requirements, not finishes. The City’s suite requirements and its guide to legalizing an existing suite list the items inspectors look for. Some of the big ones:

• Ceiling height. A basement suite needs a minimum floor-to-ceiling height of 1.95 m, which can drop to 1.85 m where ductwork and beams make drop ceilings necessary.
• Bedroom egress windows. Each bedroom needs a window that opens without keys or tools, with an unobstructed opening of at least 0.35 m² and no dimension under 380 mm. Many older basements need new or enlarged windows to meet this.
• Smoke-tight separation. At least 12.7 mm (½”) drywall on the ceiling and both sides of the walls between the suite and the main home and around the furnace room, with taped and sealed joints. Furnace room and common-area doors need to be solid and self-closing.
• Interconnected alarms. Smoke and carbon monoxide alarms must be permanently wired and interconnected so an alarm in the suite also sounds in the main home.
• Sound control. Sound-absorbing insulation in joist and stud spaces between units.
• Safe exits. Each unit needs an exit to the outside. If the suite’s only exit is an outside stair, windows in the main house close to that path may need protection.

An architect or engineer may also be required depending on the project, and separate electrical and plumbing permits apply to new or altered work. If a previous owner finished the basement without permits, the City has a concealed wiring and plumbing procedure that requires a licensed contractor, and an inspector may ask for drywall to be opened.

Permit costs, timelines and the amnesty deadline

The City’s permit costs and timelines page currently lists these building permit totals, including the 4% Safety Codes Council fee:

• Legalizing an existing secondary suite: $205.92.
• Building a new secondary suite: $403.52.
• A new backyard suite: $1,302.08.
• Homeowner electrical or plumbing permits: $116.50 each, where you qualify to do the work yourself.
• Development permit for a suite, where one is needed: $0, and registry fees are $0.

The City estimates about 7 days for a building permit to legalize an existing suite. Where a development permit is required, it lists 60 days to a decision plus a 21-day advertisement and appeal period, or roughly 10 to 12 weeks.

The date to watch is December 31, 2026. That is when the City’s Secondary Suite Amnesty Program ends. Until then, owners can avoid development permit charges and registration fees, and suites that existed before March 12, 2018 may qualify for reduced building code requirements, as long as they meet minimum life safety standards and the owner provides a declaration. The City has also said its Suite Incentive Programs closed to applications on September 28, 2026, so do not budget around a grant.

Permit fees are small next to construction. Egress windows, drywall separation, a second kitchen, electrical and mechanical work can add up quickly, and prices vary a lot from house to house. Get written quotes from licensed contractors before you count on a number.

Buying a house with a suite: how to verify it

Listings use a lot of soft language: “mortgage helper,” “in-law suite,” “basement development with separate entrance.” The Alberta Real Estate Association explains that without municipal approval a space should not be called a suite unless it is labelled illegal, and that income potential from an illegal suite should not be promoted. Here is how to check for yourself:

• Search the registry. The City’s renter guidance says that if an address does not come up on the registry, the suite is not registered.
• Ask for the paperwork. Request copies of the building permit, trade permits and final inspection. The Real Property Report can also show whether exterior stairs or window wells sit where they should.
• Put it in writing. If the suite is not legal, AREA suggests both parties acknowledge in the contract that the basement development is not a legal secondary suite, so lawyers and lenders work from the same understanding.
• Talk to your lender and insurer early. AREA notes that a permitted suite can be insured as a suite and its income may be considered by a lender. How much rental income counts toward qualifying varies by lender and program, so confirm it with your mortgage professional before you write an offer.
• Budget for legalizing. If you plan to legalize a suite after buying, have a contractor walk through it during your inspection period and compare the cost to your price.

Rental math: a hypothetical suite example

Every property is different, so treat the following as a template, not a forecast. All figures below are hypothetical and are only meant to show the method.

Hypothetical example: An owner spends $80,000 to build a legal basement suite and expects to rent it for $1,700 a month.

• Gross rent: $1,700 × 12 = $20,400 a year.
• Vacancy allowance of 4%: minus $816, leaving $19,584.
• Added costs per year: $600 more for insurance, $1,020 maintenance reserve (5% of rent), $1,800 for utilities included in rent and $500 of extra property tax. Total: $3,920.
• Net before financing: $19,584 minus $3,920 = $15,664 a year.
• If the $80,000 is borrowed at a hypothetical 6% interest-only rate, interest is $4,800 a year, leaving about $10,864, or roughly $905 a month, before income tax.

Now change the inputs. Drop the rent to $1,500 or raise the build cost to $110,000 and see what is left. A suite that only works with best-case rent and a perfect tenant is not a good plan. Our guide to Calgary rental property investment walks through the full cash flow method, including cap rate and stress tests.

There is also a resale side. AREA notes that properties with a legal, permitted suite generally sell for more and faster than comparable homes without one. A suite that is not legal can do the opposite, because buyers have to price in the cost and risk of fixing it.

Landlord rules and taxes to plan for

Renting a suite makes you a landlord under Alberta’s Residential Tenancies Act. A few basics: a security deposit cannot exceed one month’s rent, and it must be held in trust in an interest-bearing account. The Province sets the annual interest rate on security deposits, which is 0% for 2026.

Taxes deserve a conversation with an accountant before you build. The Canada Revenue Agency’s principal residence folio explains that converting part of your home into a self-contained rental unit is usually treated as a partial change in use, with a deemed disposition of that portion of the property. Since March 19, 2019, owners can generally elect under subsection 45(2) to defer that, but claiming capital cost allowance on the property ends the election. These choices affect the principal residence exemption when you sell, so get advice first.

The City also notes that adding livable space, such as a finished basement, may increase your property assessment and property taxes.

Frequently asked questions

How do I know if a suite in Calgary is legal?

Search the address on the City’s Secondary Suite Registry at secondarysuites.calgary.ca. If it appears, the suite has its permits and passed inspection. If it does not, ask the seller for permits and final inspection records.

Do I still need a development permit for a secondary suite?

Since August 5, 2026, secondary suites are a permitted use in Calgary’s low-density residential districts. A suite that meets every Land Use Bylaw rule may only need a building permit and trade permits, but a design needing relaxations can still require a development permit. Check your address with the City.

Can I have a basement suite and a backyard suite?

Not anymore. Under the 2026 changes, a property can have one or the other, not both.

When does the secondary suite amnesty end?

December 31, 2026. Until then, the City waives development permit charges and registration fees, and suites built before March 12, 2018 may qualify for reduced building code requirements.

Can I sell a secondary suite separately?

No. A secondary suite is approved together with the main home and cannot be subdivided or sold on its own.

This article is general information only and is not legal, tax, building code or financial advice. City rules, fees and programs are from the City of Calgary sources linked above as of October 20, 2026 and can change. Example figures are hypothetical. Confirm requirements for your property with the City and qualified professionals.