The Numbers Behind Calgary’s Secondary Suite Boom
This is an illustrative planning model, not a promise of rent, appreciation, or payback. We break down the costs, rental assumptions, and simple-return math a homeowner can use when evaluating a legal secondary suite in Calgary in 2026. Confirm the address-specific permit path, financing, insurance, tax treatment, and current market rent before making a decision.
Current City status (reviewed September 1, 2026): The City of Calgary’s Secondary Suite Incentive Program page currently places new applications on a waitlist and says funding may not be available. Treat every calculation below as pre-incentive unless the City confirms your intake and eligibility in writing.
What Does a Legal Suite Cost to Build?
Based on OAF Construction’s project data across Calgary, the typical cost of a legal basement secondary suite in 2026 ranges from $65,000 to $120,000. The variation depends on several factors:
- Suite size. A 500 sq ft one-bedroom suite sits at the lower end; a 900 sq ft two-bedroom suite with full kitchen and separate laundry approaches the upper end
- Existing conditions. Homes with existing rough-ins for plumbing and egress windows cost less to convert
- Finish level. Builder-grade finishes versus premium materials can account for a $15,000 to $25,000 difference
- Fire separation. Older homes may require more extensive work to achieve the 1-hour fire-rated separation required by code
- Permits and engineering. Typically $2,500 to $4,500 depending on scope
If the City confirms an eligible SSIP payment, it may reduce the owner’s cost by the amount approved. Do not subtract the program maximum from a budget before the City confirms current intake, eligible work, and funding.
What Can You Charge in Rent?
The table below is a directional asking-rent assumption for scenario planning, based on OAF’s Calgary listing review. It is not an appraisal or a guaranteed achievable rent; location, size, parking, utilities, furnishing, and vacancy can move the result materially. Check comparable live listings for the specific neighbourhood before using a figure in your own model.
| Suite Type | Average Monthly Rent |
|---|---|
| 1-bedroom basement suite | $1,200 to $1,500 |
| 2-bedroom basement suite | $1,500 to $1,800 |
| 1-bedroom with separate entrance and parking | $1,400 to $1,700 |
| 2-bedroom with in-suite laundry | $1,700 to $2,000 |
These figures are based on OAF’s review of Calgary listings in established neighbourhoods including Tuscany, Panorama Hills, Coventry Hills, McKenzie Towne, Auburn Bay, and Midnapore. Inner-city and Beltline-adjacent listings may command a premium, but verify comparable live listings for the specific property.
Illustrative ROI Calculation
For one illustrative scenario, assume an $85,000 legal-suite build (before any incentive), $1,500 monthly rent, and the operating assumptions below:
Annual rental income: $18,000 Less vacancy (5%): -$900 Less maintenance and repairs (5%): -$900 Less insurance increase: -$300 Less utilities increase: -$1,200 Net annual income: $14,700
Net investment (before any confirmed incentive): $85,000 Simple payback period: 5.8 years Annual cash-on-cash return: 17.3%
This excludes financing, taxes, capital reserves, management, and vacancy beyond the assumed 5%. It is a simple operating model, not an investment forecast.
Property Value Impact
An appraiser or lender may give a legal, code-compliant suite contributory value, but the result depends on the property, market comparables, documentation, and the appraiser’s methodology. Do not underwrite a specific value increase without a current appraisal or lender opinion.
The key word is “legal.” An unpermitted suite may be discounted or excluded by an appraiser or lender, and unresolved compliance can reduce marketability or create liability concerns for buyers and insurers.
Tax Considerations
Rental income from a secondary suite is generally reportable in Canada. The CRA’s Rental Income guide explains that reasonable current expenses may be deductible while capital costs are treated differently; use a tax professional for your facts. Common items to discuss include:
- Mortgage interest. Proportional to the suite’s share of total home square footage
- Property taxes. Same proportional calculation
- Insurance. The incremental cost of adding the suite
- Maintenance and repairs. Costs directly related to the suite
- Capital Cost Allowance (CCA). You can depreciate the construction cost, though this has implications when you sell
Consult a tax professional before treating any deduction or tax effect as part of your return.
The Bottom Line
A legal secondary suite can be financially attractive when the address supports the use, the build stays on budget, and the suite rents consistently. The model above shows how sensitive the result is to rent, vacancy, operating costs, financing, and the amount (if any) the City confirms under SSIP.
The critical factor is building it legally, to code, with the permits and inspections required for the address. Legal status supports insurability and resale documentation; it does not itself guarantee a rebate, appraisal result, or rent level. Review the City’s secondary-suite requirements before committing to a layout.
OAF Construction specializes in legal secondary suite development across Calgary. Contact us for a free consultation and fixed-price quote.
Related reading
- How Much Does Basement Development Cost in Calgary? (2026 Prices)
- Calgary Basement Development Service
- Calgary SSIP Grant: Up to $10,000 for Legal Suites
- Backyard Suite Incentive Program
Sources and method: City of Calgary - secondary-suite development permit requirements, secondary suites overview, and Secondary Suite Incentive Program; Canada Revenue Agency - Rental Income guide. Rent figures are OAF directional planning assumptions from a Calgary listing review, not guaranteed market rent. Reviewed September 1, 2026; confirm current program, permit, tax, and market details before relying on them.