Patrick C. and his wife have outgrown their current home in Ottawa with a third child on the way this spring. He’s a professional engineer with a stable income, while she will be on leave for a year and return to contract work with the school district.

They would normally qualify for a purchase price up to $500,000, which would give them ample room to find a suitable four-bedroom home close to work in the high tech area of the city where they now live and children attend school. With the mortgage rule changes, Patrick and his wife can only get up to $450,000, and there are virtually no four-bedroom listings in that price point in the area they currently live.

They will require a co-signer to make the deal work under the new rules hoping that a parent can assist despite previously owning two homes without that requirement.