How to create a legal second suite

Bob Aaron in Legal

One of the biggest mysteries of the local real estate market is the legality of basement apartments – also known as granny flats, in-law suites, accessory apartments or non-retrofit units.

Toronto bylaws permit basement apartments in all single detached and semi-detached homes, subject to certain requirements. Determining just what those requirements are, and whether any of the tens of thousands of basement apartments in Toronto are legal, is a tall order.

The City of Toronto has prepared a kit that provides information on how to create a legal second suite. It's available at the Access Toronto desk at municipal offices (or 416-338-0338). It's somewhat shy on the actual physical requirements, including unit size, fire protection, zoning, parking, window area, ceiling height, exit requirements, etc. Recently I came across a superb explanation of the basement apartment issue. It's on the website of Carson Dunlop, a well-known firm of home inspectors and consulting engineers (

The report starts off with the big Catch-22: "Homeowners with a basement apartment would like to find out what it would take to 'legalize' the apartment," it says, "but they want to find this out without tipping off the authorities."

The answer, according to Carson Dunlop, involves five issues:

  • Do the local bylaws permit you to have a basement apartment?
  • Does the apartment comply with the Fire Code?
  • Does it comply with basic building code requirements?
  • Does it comply with basic electrical safety requirements?
  • Has the apartment been registered?

Under Ontario law, a permit is required to add a new basement apartment to a single family house. In 1994, the NDP government overrode local bylaws prohibiting basement units, if certain conditions were met. New Fire Code rules were introduced, and they apply to all basement apartments.

Carson Dunlop suggests checking the zoning bylaw at city hall and applying for a building permit. The new unit will have to comply with current building codes.

For existing units, the first step is to check with Municipal Property Standards or the fire department for a certificate of compliance. If there is one, the apartment is legal.

If not, the next step is to have the fire department inspect the home to verify compliance with the Fire Code. The four key areas of this inspection involve fire containment and fire-rated drywall separations from the remainder of the house; fire exits (including qualifying windows); fire detection and alarms; and electrical safety.

Following the fire inspection, an Electrical Safety Authority inspection is required.

Several rules apply to all basement units:

  • All bathrooms need either a window or an exhaust fan
  • If there is a parking spot for the upper unit, there must also be a parking spot for the basement
  • The minimum ceiling height must be 6-feet 5-inches
  • The entrance door size must be at least 32 inches by 78 inches

If the unit passes all the required inspections, it can be used, advertised and sold as a legal basement apartment. In my experience, if a house is advertised or listed as having a basement apartment, and there is no mention that the unit is legal, it probably isn't.

For anyone buying, selling, building, or arranging insurance for a basement apartment, the best advice is to complete the required inspections and always make full disclosure.

Bob Aaron is a sole practitioner at the law firm of Aaron & Aaron in Toronto and a board member of the Tarion Warranty Corp.  Bob specializes in the areas of real estate, corporate and commercial law, estates and wills and landlord/tenant law. His Title Page column appears Saturdays in The Toronto Star and weekly on Move Smartly.  E-mail

Subscribe to the Move Smartly blog by email

Legal     |    

Toronto’s most authoritative real estate insights, delivered right to your inbox.