Planning policies in many North American cities have led to an increase in demand for housing in and around major cities due to the predominance of low-density, single-family housing. Recent changes to such policies now allow and prescribe (as per by-laws) the construction of a second dwelling on many properties with an existing house. This second residential dwelling is sometimes known as an accessory/ancillary/secondary dwelling unit, granny flat, or in the case of Toronto, a laneway house (LWH). Faced with increasing housing costs and restricted growth, Toronto homeowners would like to know if they can develop their properties to accommodate LWHs.
Dencity is an online tool that helps you determine whether you can build an as-of-right LWH (conforming to by-laws), how much it will cost, how much area you can build, and what the financial return may be. While not supplanting the expertise of professional consultants, this tool may help you establish an initial understanding of how you can develop your laneway property to accommodate another liveable space.
Dencity's calculations are based on City of Toronto open data files. Combined with zoning by-laws, these files establish key parameters that dictate your as-of-right laneway house's (LWH) design. Dencity is as accurate as the files it pulls information from, and discrepancies resulting in inaccuracies or variations from the in situ reality of any given property should be understood through this lens. Any information garnered from the tool should be considered as preliminary planning information only. Costing resources include Hanscomb Yardsticks for Costing, RSMeans, and other online resources. Interested homeowners should always consult licensed professionals (architects, contractors, City planners, banking/mortgage representatives, etc.) and confirm with the City that the proposed LWH area does not exceed the gross floor area of their primary house before embarking on a laneway house project.
Dencity shows users the maximum allowable square footage they can build a 1 or a 2 storey as-of-right LWH. The app also uses the allowable building area to inform its costing tool. Once at the costing step, users may input their specific financial information to allow for greater flexibility in adjusting computation.
Quickly check if your property qualifies for an as-of-right laneway house (LWH) and how much it might cost. Note that even if Dencity lists a property as not being viable, the in situ reality may differ from the data sourced. Homeowners should check their property's viability by measuring and checking that LWH zoning criteria can be met. In addition, homeowners may apply to Committee of Adjustment for non-conforming LWHs that vary from the zoning by-law.
Automatically see how much area you can build your LWH in, visualized on your property, with options for 1 and 2 storey buildings.
Use Dencity's financial calculator to come up with a baseline to inform your construction budget and return on investment. City of Toronto LWH financial incentives have been incorporated.
Planning policies featuring low-density, single-family housing in many North American cities have resulted in increased demand for housing in and around major cities. While recent high-density development has launched huge condominium growth in places like Toronto, land dedicated to single-family housing remains incredibly low in occupancy, with no foreseeable increase to middle- or high-density permitted in the future. Given the significant increase in housing prices, restricted growth, long commute times, as well as changing family and work needs, there is now a need to moderately increase density in low-rise residential zones.
Seeing the need to fill in this missing middle ground, various North American municipalities, including Toronto, have granted homeowners the option to construct an accessory dwelling unit in their backyard. Standard Toronto houses typically have a backyard, street access at the front, and a lane at the rear. Properties with rear or side yard access to lanes are permitted to have these units, referred to as laneway houses (LWHs).
Toronto’s 2018 as-of-right housing by-law (810-2018) and subsequent 2019 amendment allow Torontonians to build as-of-right laneway housing in the city, which must abide by certain zoning criteria (below). The City encourages the development of LWHs, as they help people live close to where they work, and keep lanes “green, liveable, and safe.” The City defines a laneway suite as a “self-contained residential unit, subordinate to a primary dwelling, in which both kitchen and bathroom facilities are provided and located on a lot within an ancillary building, adjacent to a public laneway. Laneway suites provide an additional form of contextually appropriate low-rise housing within the City’s neighbourhoods and are part of complete communities.” Interested homeowners are encouraged to explore the City of Toronto’s laneway housing suites website (here) to acquaint themselves with official guidelines. A detailed explanation of Toronto's LWH zoning parameters follows below.
Show Zoning Criteria for Toronto ▼
Rachel is an architect with many years of experience working in various architecture practices in Canada and abroad. She brings her knowledge of GIS mapping as well as Toronto residential planning and costing to Dencity.
Tapping into his data science skills, Christoph's ability to transform the applicable data files into components of a useful tool gives Dencity its formwork. When not working on mapping cities, Christoph applies his data expertise in the world of biotech.