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Secondary Suites Are Booming in Calgary — Could the Rental Income Help You Qualify for a Mortgage?

September 14, 2026

Calgary secondary suites are booming. Learn when rental income from a basement suite may help you qualify for a larger mortgage.
Secondary Suites in Calgary

Secondary suites are becoming a much bigger part of Calgary’s housing market.

The City of Calgary says there are now roughly 26,000 registered secondary suites, double the approximately 13,000 on the registry in 2024. The growth has been helped by streamlined approvals and a City incentive program that offered qualifying homeowners up to $10,000 toward creating or legalizing a suite.

As of August 5, Calgary has also made secondary suites a permitted use in low-density residential districts. In practical terms, that removes one potential planning hurdle for homeowners whose projects meet the applicable rules. For homebuyers, however, there is another question worth asking: can the income from that basement suite actually help you qualify for the mortgage? The answer is yes — sometimes quite significantly — but it isn’t quite as simple as adding the expected rent to your salary.

Quick answer: Rental income from a secondary suite can help you qualify for a mortgage, not just help you make the payment. CMHC allows up to 100% of gross rental income to be considered on an owner-occupied two-unit property when that property is the subject of the application, and Sagen similarly allows 100% for qualifying owner-occupied two-unit properties. The catch is proof: the lender normally needs the rent supported by an existing lease or a fair-market rent determined through an appraisal, and it has to be satisfied with the suite itself — a finished basement with a fridge and a separate entrance isn’t automatically a suite a lender will count. Calgary’s suite registry has roughly doubled since 2024 to about 26,000, so the question comes up far more often than it used to.
26,000
Registered secondary suites in Calgary today
100%
Of gross rent CMHC may count on an owner-occupied two-unit home
65%
Of buyers with a suite called it important when choosing the home
$18,000
A year, if a suite rents for $1,500 a month

Are Calgary buyers actively looking for homes with suites?

A woman and a man in a blazer standing on the front walk of a two-storey house, the man gesturing toward a separate ground-level side door beside a basement window well
The separate entrance is the first thing buyers notice — but it’s the registration and the lease, not the door, that decide whether a lender counts the rent.

Secondary suites aren’t just something homeowners think about adding later. CMHC’s 2026 Mortgage Consumer Survey found that 21% of mortgage consumers had a secondary suite. Among homebuyers who had one, 65% said the suite was an important factor when choosing their home.

That doesn’t surprise me. For a first-time buyer trying to make the numbers work in Calgary, a home with a basement suite may offer something a similar home without one doesn’t: another source of income to help offset the mortgage. But there is an important distinction between rent helping you make your monthly payment and rent helping you qualify for the mortgage in the first place.

Can a lender use the suite’s rental income to qualify you?

Mortgage insurers have specific methods for including rental income when qualifying borrowers. For example, CMHC allows up to 100% of gross rental income to be considered on an owner-occupied two-unit property when the property being purchased is the subject of the mortgage application. Other situations can be treated differently, including properties with three or four units and non-owner-occupied properties.

Sagen similarly allows 100% of rental income for qualifying owner-occupied two-unit properties, subject to its requirements. That can make a meaningful difference. If a basement suite could reasonably rent for $1,500 per month, that’s $18,000 per year in potential rental income. Depending on the lender, insurer, property and mortgage structure, some or all of that income may help with qualification.

But please don’t take that example and immediately add $18,000 to your salary in an online mortgage calculator. Mortgage underwriting enjoys making simple arithmetic more interesting than it needs to be.

How does the lender prove the rent is real?

A couple standing at the top of a staircase looking down into a bright lower-level living room and kitchen that has its own exterior door
What the insurer wants to see isn’t the finishes — it’s a signed lease or an appraiser’s fair-market rent figure attached to the file.

A lender won’t normally accept a number simply because the listing says, “Basement could rent for $1,800!” The rental income may need to be supported by documentation such as an existing lease or market rent determined through an appraisal. Sagen, for example, permits income to be validated using signed leases or fair-market rent from an appraisal for qualifying owner-occupied two-unit properties.

The lender and insurer also have to be satisfied with the property itself. A beautifully finished basement with a fridge and a separate entrance isn’t necessarily a suite that a lender will treat the way you expect.

Does the suite have to be registered and compliant?

Calgary’s changes are particularly relevant here. Secondary suites are now permitted uses in low-density residential districts, but they still have to comply with the applicable land-use, building and safety requirements.

That is one reason I would investigate the suite before writing an offer around the assumption that its rental income will make the mortgage work. I want to know whether the suite is registered, what rent the lender is likely to accept, how that income will be calculated and whether the particular lender or insurer we’re using has additional requirements.

Sagen’s current underwriting guidance, for example, says properties should comply with zoning and applicable bylaws, while rental income from an unauthorized suite may be considered on a case-by-case basis. “There’s a tenant downstairs paying $1,600” and “the lender will use $1,600 for qualification” are not necessarily the same statement.

What if you want to build the suite after buying?

A woman and a man holding rolled blueprints in an unfinished basement with exposed framing, insulation and plumbing, the man pointing at a newly framed doorway
Insured refinance programs for adding a suite want plans, cost estimates and permits up front — which is why the financing gets structured before the demolition starts.

That’s another possibility. Mortgage financing can sometimes be structured around improvements to a property, and there are now insured refinancing options specifically designed for homeowners adding secondary suites.

CMHC’s refinance program for building secondary suites allows qualifying homeowners to finance eligible improvements and sets out requirements including plans, cost estimates and permits. Sagen also permits projected rental income from newly built units to be used for qualification under its secondary-suite refinance program when the rent is supported by an appraiser’s fair-market-rent assessment.

That’s potentially useful, but again, it needs to be structured properly. You generally don’t want to buy the house first and figure out whether the financing works later.

How much can a suite change what you can afford?

Josh Tagg speaking to camera at his desk in front of a Mortgages for Less wall logo, a monitor beside him listing five steps to buying your first home
The number that matters is the one run against the actual property and the actual lender — before financing conditions come off, not after.

Calgary’s secondary-suite boom isn’t only a story about adding more rental housing. For some buyers, it could change the economics of homeownership.

A house with a suitable basement suite may allow rental income to offset part of the cost of owning the property and, depending on the mortgage program, may also help the buyer qualify for the mortgage. But I wouldn’t shop based on the rent alone.

If you’re considering a Calgary home with a secondary suite, I can run the mortgage numbers using the actual property, expected rental income and the lenders available to you. That tells us whether the suite genuinely increases your purchasing power before you remove financing conditions — which is a considerably better time to find out than the week before possession.

How an Alberta mortgage broker helps with a suited property

A suite turns one straightforward mortgage question into several. Here is what we sort out before you write the offer:

  • We confirm whether the suite is registered and how that changes the lenders and insurers available to you.
  • We tell you what rent the lender is likely to accept — not the number on the listing.
  • We show you how that income is calculated in your ratios, since insurers treat two-unit, three-or-four-unit and non-owner-occupied properties differently.
  • We line up the proof the file will need: an existing lease, or a fair-market rent figure from the appraisal.
  • We compare buying a home that already has a suite against adding one later under an insured secondary-suite refinance program.
  • We put a real monthly payment beside each scenario, so you know whether the suite actually increases your purchasing power before financing conditions come off.
Who to call if this sounds like you. Josh Tagg is a Calgary mortgage broker who has been arranging mortgages across Alberta since 2006. He leads the Mortgages for Less team at INDI Mortgage, took over the brokerage his father founded in 2003, and is licensed by the Real Estate Council of Alberta. Suited and rental-income files are ordinary work here. Whether a secondary suite actually increases what you can borrow depends on the lender, the insurer, whether the suite is registered and how much of the rent gets counted — and those answers differ enough to change the price of house you can buy. Establish it before you write an offer, not after your financing condition is gone. See rental and investment property for the rest of what we handle. Call (403) 241-3255, book a call, or apply online — it is free, there is no credit check to start, and there is no obligation.

Thinking about a Calgary home with a suite?

Let’s run the numbers on the actual property and the actual rent, with the lenders available to you — before you remove your financing condition.

Apply Online → Book a Discovery Call → Serving Calgary, Edmonton & all of Alberta · Mortgages for Less with INDI Mortgage

Secondary suites and mortgage qualifying: common questions

How many secondary suites does Calgary have now?
The City of Calgary says there are now roughly 26,000 registered secondary suites, double the approximately 13,000 on the registry in 2024. The growth has been helped by streamlined approvals and a City incentive program that offered qualifying homeowners up to $10,000 toward creating or legalizing a suite.
Can rental income from a basement suite help me qualify for a mortgage?
Yes, sometimes quite significantly, but it isn’t as simple as adding the expected rent to your salary. CMHC allows up to 100% of gross rental income to be considered on an owner-occupied two-unit property when the property being purchased is the subject of the mortgage application. Sagen similarly allows 100% of rental income for qualifying owner-occupied two-unit properties, subject to its requirements. Other situations can be treated differently, including properties with three or four units and non-owner-occupied properties.
How much difference does suite income actually make?
If a basement suite could reasonably rent for $1,500 per month, that’s $18,000 per year in potential rental income. Depending on the lender, insurer, property and mortgage structure, some or all of that income may help with qualification. Just don’t take that example and add $18,000 to your salary in an online mortgage calculator.
What documents does a lender need to prove the rent?
A lender won’t normally accept a number simply because the listing says the basement could rent for $1,800. The rental income may need to be supported by documentation such as an existing lease or market rent determined through an appraisal. Sagen, for example, permits income to be validated using signed leases or fair-market rent from an appraisal for qualifying owner-occupied two-unit properties.
Does the suite have to be registered or legal?
Secondary suites are now permitted uses in Calgary’s low-density residential districts, but they still have to comply with the applicable land-use, building and safety requirements. Sagen’s current underwriting guidance says properties should comply with zoning and applicable bylaws, while rental income from an unauthorized suite may be considered on a case-by-case basis. A beautifully finished basement with a fridge and a separate entrance isn’t necessarily a suite that a lender will treat the way you expect.
Can I finance building a suite after I buy the home?
Mortgage financing can sometimes be structured around improvements to a property, and there are now insured refinancing options specifically designed for homeowners adding secondary suites. CMHC’s refinance program for building secondary suites allows qualifying homeowners to finance eligible improvements and sets out requirements including plans, cost estimates and permits. Sagen also permits projected rental income from newly built units to be used for qualification under its secondary-suite refinance program when the rent is supported by an appraiser’s fair-market-rent assessment.
Should I make an offer assuming the suite income will make the mortgage work?
I would investigate the suite before writing an offer around that assumption. I want to know whether the suite is registered, what rent the lender is likely to accept, how that income will be calculated and whether the particular lender or insurer we’re using has additional requirements. Running the numbers on the actual property tells us whether the suite genuinely increases your purchasing power before you remove financing conditions, which is a considerably better time to find out than the week before possession.

This article is general information for Alberta homebuyers, not financial, mortgage, tax or legal advice. Municipal suite rules, insurer guidelines and lender policies change, rental income treatment varies by lender, insurer, property and mortgage structure, and any mortgage is subject to lender approval. Please speak with a licensed mortgage professional about your specific circumstances. Mortgages for Less with INDI Mortgage.

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