The agency announced Monday that, from September 28, it will allow 100 per cent of the rental income from a unit to be considered for new loan applications submitted to it for mortgage insurance.

That means that a secondary rentals suite’s income, minus costs including property taxes, will boost the size of the loan that buyers can secure.

Qualifying units must have sustainable income, proven by two years of rental rent payments. These payments will be averaged to assess the unit’s income. Applicants will also need a credit rating of at least 680.

Properties with more than a single rental unit will have slightly different rules and this change is most positive for homeowners with one rental unit.