Home Additions in Toronto

In Toronto, building an addition to an existing house needs a building permit. Toronto’s examples include second or third storey additions, attached garages, carports, sunrooms, solariums, porches and decks. Toronto is a single-tier city, so Toronto Building checks the zoning on the application, issues the permit and carries out the inspections. Toronto reviews lot grading through the building permit. On an ordinary lot the grades for an addition go on the permit drawings.

If the lot is in a TRCA Regulated Area, yes: building anything there needs a TRCA permit, and Toronto will not issue the building permit until you have it. TRCA also asks for a pre-submission consultation, which we book as soon as the survey shows a valley or creek near the house.

Yes, if it fits the zoning, and that is the first thing we check. Toronto’s comprehensive, city-wide zoning by-law is Zoning By-law 569-2013, although some properties are still subject to the zoning by-laws of the former pre-amalgamation municipalities. We check which of them governs your lot, then measure the addition against that by-law’s setbacks, height and coverage.

If your house is in one, that district’s rules apply to the addition. Toronto has Heritage Conservation Districts designated under Part V of the Ontario Heritage Act. They include Blythwood Road, Cabbagetown (North, Northwest, Metcalfe and South), Cabbagetown Southwest, Draper Street, East Annex, Fort York, Garden District, Harbord Village, Historic Yonge Street, Kensington Market, King-Spadina, Kingswood Road South, Lyall Avenue, West Annex Phase 1: Madison Avenue, Parkdale Main Street, Queen Street West, Riverdale, Rosedale (South and North), St. Lawrence Neighbourhood, Teiaiagon-Baby Point, Union Station, Weston Phase 1, Wychwood Park and Yorkville - Hazelton. We check your address against the district boundaries first.

Yes. We take on home additions across Toronto, including North York and Scarborough, about half an hour from our Richmond Hill office. The first consultation is free, by phone or on site.

Three things to start: property address and a survey, if you have one; what you want to add and where; and photos of the side of the house and the yard where it would go. Send those and we tell you what Toronto Building will ask for before we quote.

It can. A rear addition’s footings are dug into the yard, and Chapter 813 of the Toronto Municipal Code needs a permit before anyone injures a private tree of 30 cm or more in diameter, measured 1.4 m above the ground; City street trees are protected at every size. We locate the trees from your survey before the footprint is fixed, so the addition can step back from a root zone, or the tree permit is applied for while Toronto Building reviews the set.

Yes, if the unit count fits the zoning. Toronto’s rules allow multiplexes of up to four units anywhere in the city and up to six in the Toronto and East York District and Ward 23, so an addition can hold a second, third or fourth unit where the lot qualifies. The new unit is drawn as a separate dwelling, with the separation and exits the Building Code asks for, and we confirm the lot under By-law 569-2013 or its former municipal by-law before the addition is sized around it.

It may. Since November 21, 2025, a minimum setback in a zoning by-law has been deemed to be 90 per cent of the stated distance on urban residential land outside the Greenbelt, with hazardous lands and some other areas excluded. On a narrow Toronto lot, that margin can decide whether a side or rear addition needs a minor variance under By-law 569-2013, so we confirm with Toronto Building’s zoning examiners how it applies to your lot before relying on it.

You can appeal or change the design. In Toronto, appeals of Committee of Adjustment decisions go to the Toronto Local Appeal Body, and since November 28, 2022 only the applicant, the Minister, specified persons and public bodies have been able to appeal. The other route is a smaller variance and a fresh application, for example with a second storey stepped back from the side lot line. Either way Toronto Building cannot issue the permit until the variance is final or the design meets By-law 569-2013, and we redraw the addition for whichever route you choose.

Toronto’s guide for small residential additions asks for the setbacks, the building area, the lot coverage and the grade elevations, the last so Toronto Building’s examiner can confirm the height under Zoning By-law 569-2013, or under the former municipal by-law that still governs some lots. All of it is measured from a survey, so if yours does not show the house as it stands now, including any earlier addition or garage, we arrange a new one.