Lenders may use an accepted portion or net amount of rental income when qualifying a property with a legal or acceptable secondary unit, but documentation and calculation methods vary.
Four points to remember
- Not every dollar of projected rent is automatically added to qualifying income.
- CMHC permits different gross-rent and net-rent approaches depending on occupancy and number of units.
- The lender may require a lease, market-rent appraisal and evidence the unit is acceptable.
- A household should test cash flow after vacancy, repairs, utilities and tax.
Identify the property and occupancy
Qualification differs for an owner-occupied home with one secondary unit, a three- or four-unit owner-occupied property and a non-owner-occupied rental. Start with the legal unit count and intended occupancy.
- Owner occupied or rental
- Number of self-contained units
- Zoning, permits and insurance
Understand gross and net methods
Some programs may use up to an accepted percentage of gross rent, while others subtract operating expenses and use net rental income. The lender chooses an eligible method under its policy and insurer rules.
- Gross-rent add-back
- Rental offset
- Net operating income approach
Prepare acceptable rent evidence
Current leases, deposit records, tax returns or a market-rent appraisal may be requested. Projected Airbnb or informal cash rent should not be assumed to qualify like a documented long-term tenancy.
- Signed lease and rent deposits
- Appraiser market-rent schedule
- Tax and expense records
Test the property as a business
Even if rent helps qualification, the homeowner remains responsible when the unit is vacant or repairs are required. Model mortgage, tax, utilities, insurance, maintenance and a vacancy reserve.
- Conservative monthly cash flow
- Repair and vacancy reserve
- Landlord and insurance obligations
Frequently asked questions
Will a lender count 100% of basement rent?
Some insured owner-occupied two-unit scenarios may allow an approach using up to 100% of gross rent, but lender, insurer and document requirements still apply.
Does the basement apartment have to be legal?
Property acceptability, zoning, safety and insurance matter. Lenders may require evidence and may not use income from an unacceptable unit.
Can projected rent help before a tenant moves in?
It may, when supported by an acceptable market-rent appraisal and program rules. The lender decides what evidence and method it will use.
Official sources and verification
This guide prioritizes primary information from governments, regulators and CMHC. Mortgage policies change; confirm the rules that apply when you apply.
This guide and its calculators are for general education only—not an approval, commitment, or legal, tax or investment advice. Actual rates, fees, underwriting and product terms vary by lender and application.