BUILDING PERMIT DRAWINGS FOR FOURPLEX

Ontario is facing significant housing challenges and increasing supply is becoming a strategic priority for all levels of government. 

A fourplex is a residential building with four units with at least one dwelling unit located entirely or partially above another.  An existing house also can be converted as a fourplex or an addition to an existing house can be built to have a fourplex that is divided horizontally and/or vertically into four separate dwelling units, each with an entrance that is either independent or through a common vestibule. Four attached dwelling units built side-by-side would generally be considered as townhouses.

Fourplexes expand the range of low-rise housing forms and tenures, and make efficient use of existing infrastructure and services. Fourplexes increase the supply of rental housing and support the achievement of complete communities to accommodate a diverse range of household sizes and incomes. Fourplexes are considered a form of residential infill intensification that is compatible in built form and scale to surrounding development.

More fourplexes will make living in Toronto, Mississauga and Kitchener far more affordable. Typical conversion of a detached home into a fourplex invloves build an addition into the rearyard and divide the building into four two-bedroom dwelling units, one on the main floor, two on the second floor and one in the basement. 

The important fact is a fourplex will aways generate exceptional rent revenue, positive cash flow and significant increase to the market value, though a constructing a fourplex is cash heavy upfront and requires significant capital.  Most of the property owners build rental fourplexes to have rental income or to reside alongside the extended family, or tenants. 

 
The municipality requires drawings of the proposal to have a fourplex so the City can determine if the proposed fourplex is safe and complies with the municipal Zoning By‑law, the Ontario Building Code, and any other applicable law.   A site plan application process is NOT required for residential buildings with four to 10 total dwelling units that do not contain other uses within the building or on the property.  

Municipalities can still choose to allow fourplexes in their built-up residential neighbourhoods. Some municipalities in Ontario already have zoning by-laws to allow more density, but building multi-unit dwellings across the province is limited and prevented by lack of water and sewer infrastructure in rural residential neighbourhoods. 

Individual ownership of dwelling units in fourplex would only be possible by registering a condominium corporation, an expensive cumbersome process that’s not usually applied to a fourplex.

Fourplexes in Mississauga

The City of Mississauga has approved a motion to allow residents to build fourplexes on low-rise residential lots. 

The City of Mississauga's new by-laws:

• Permit fourplexes “as of right” which means applicants can apply for a building permit without additional zoning permissions if they meet by-law regulations.
• Support purpose-built fourplexes or the conversion of an existing property to accommodate fourplex.
• Allow a variety of fourplex configurations up to three storeys in height including a partially above-grade basement unit.
• Support the creation of rental units in neighbourhoods.

The City of Mississauga has developed purpose-built fourplex regulations for the majority of lots that permit detached dwellings in the City of Mississauga. As a result, purpose-built fourplex regulations are basedon the R5 zone, which is the smallest standard base zone for detached dwellings, with a minimum lot area and lot frontage of 295 sq.m (3,175 sq.ft.) and 9.75 m (32 ft), respectively. 

Purpose-Built Fourplex Regulations in Mississauga

In Mississauga, a new fourplex is permitted only in the following zones: Rl to Rll, Rl5, R16, RMI, RM2 and RM7.

Maximum Height : 10.6 m (34.8 ft.) to the peak of a sloped roof;  8.1 m (24.6 ft.) to the top of a flat roof

Minimum Front Yard : 6.0 m (19.7 ft.)

Minimum Interior Side Yard : 1.2 m (3.9 ft.)

Minimum Rear Yard : 7.5 m (24.6 ft.)

Minimum Exterior Side Yard : 4.5 m (14.8 ft.)

Maximum Lot Coverage:  Additional 10% above the base zone, but only for the purpose of a fourplex

Maximum Dwelling Depth: 20 m (65.6 ft.)

Required Parking Spaces: 2 (No additional requirement)

In Mississauga, an additional residential unit can’t be built on a lot that has a fourplex. Different regulations apply in Mississauga based on whether the fourplex is converted from the existing home or a new build.

Fourplex conversions are low-rise residential buildings that have been remodelled to accommodate four separate units. In this case, all four units must fit within the building footprint of the home that existed as of December 6, 2023. Additions can’t be built to accommodate four units - The enlargement of a detached dwelling legally existing on December 6, 2023, for the purposes of conversion to a fourplex shall not be permitted.

A purpose-built fourplex is a new residential building that’s designed and built to accommodate four separate apartments. These fourplexes are subject to the City of Mississauga's new zoning regulations, which provide more flexibility than the conversion of an existing home, which includes additional height, reduced setbacks, and increased lot coverage.

In Mississauga, the Average Grade means with reference to a detached fourplex, the average of eight grade elevations, six of which are taken along the side lot lines of a lot and two of which are taken at the centreline of the street on which the lot has frontage. The first two grade elevations shall be taken at the points of intersection of the front lot line and each side lot line. The second two grade elevations shall be taken along each side property line at the minimum front yard setback requirement of the zone in which the fourplex is located. The third two grade elevations shall be taken along each side prope1iy line at a distance of 15 m back from where the second two grade elevations were measured. The last two grade elevations shall be taken at the points of intersection of the street centerline and the projections of the side lot lines.

In Mississauga, the height of a fourplex means, the vertical distance between the average grade and: 

• the highest point of the roof surface of a flat roof, including a parapet; 
• the mean height level between the eaves and ridge of a sloped roof; or
• the mean height level between the eaves and the highest point of the flat roof where there is a flat roof on top of a sloped roof;

The permitted maximum height for purpose-built fourplexes in Mississauga would facilitate three storey buildings with a sloped roof and two-storey buildings with a flat roof, while allowing for flexibility for a partially above-grade basement unit. This added flexibility in height is important as bedrooms and living spaces in basement units require minimum window sizes under the Ontario Building Code.

In an R5 zone in Mississauga, the proposed yards outlined above would facilitate a minimum required floor area of 105 sq.m. (1,130 sq.ft.) per storey, including any internal stairs. 

In addition, the required minimum side yard setbacks would facilitate windows on both side walls of the fourplex without major restrictions in the Ontraio Building Code. With a three storey building and a basement unit, each unit would be able to comfortably accommodate a three-bedroom, family-sized unit. For larger lots, maximum permitted dwelling depth of 20 m (65.6 ft) limits potentially oversized fourplexes.

A purpose-built fourplex necessitates more flexibility with lot coverage, and therefore, additional 10% is permitted for a fourplex (e.g. 50% whereas the base zone permits 40%).

On larger, wider lots, required parking may be accommodated in the rear yard, with access from the side yard, which is common with many existing fourplexes in the City of Mississauga. This approach would allow the front yard space to be used as amenity area. On the other hand, smaller narrower lots will be required to accommodate the required parking in the front yard or in an attached garage, resulting in the rear yard being used as amenity area.

In order to maintain amenity space on the property, and to make fourplexes feasible across Mississauga, no additional parking spaces be required by the City of Mississauga for fourplexes. On lots that are large enough to have extensive rear yards, and wide enough to accommodate a driveway in an interior side yard, a maximum of four parking spaces be permitted in the rear yard by the City of Mississauga. The City of Mississauga's zoning by-law is already permissive to allow for hard surface in the rear yard, provided that 0.61 m (2 ft.) is maintained along the lot lines for drainage.We believe that every project is unique and requires a customized approach. We work closely with our clients to understand their specific needs and goals, and we develop solutions that are tailored to their requirements. Our approach ensures that our clients get the best possible outcome from their investment.