What records explain fourplexes, basement units and garden suites at a Mississauga home?

The City's page says the owner of a detached, semi-detached or town home may build up to two additional residential units, such as a basement apartment or a garden suite, or a fourplex: a new four-unit building or a conversion of the house into four units. Council approved fourplexes on low-rise residential lots on 7 December 2023, as of right, meaning a building permit can be sought without further zoning approval where the plans meet the by-law, in configurations up to three storeys. The rules sit in the additional residential unit by-law and the fourplex by-law, both amendments to Zoning By-law 0225-2007, and the City's property information tool shows the zoning for a lot.

Every second unit must meet the Building Code, the Fire Code and the zoning by-law and be registered with the City, at no fee; registered units appear on the City's Second Units Registry List, updated monthly. A general permission does not make an existing basement apartment lawful, and every new unit needs a building permit.

• Building more units on your property: the City's page on additional units and fourplexes, with both by-laws
• Fourplexes approved for Mississauga neighbourhoods: the City's news release on Council's decision, 7 December 2023
• Registering a second unit: registration and the Second Units Registry List

Extra units allowed is in the free check as a summary of the City's rule, from our hand-kept table of city rules, and the full report reads the lot's zone where the City's zoning map is open data we can use; where it isn't, the report's line says where the City publishes it. Neither is confirmation that a particular unit holds a permit or may be occupied.

Free check: pick “Extra units allowed” See the sample report