What records explain additional residential units at a Collingwood home?

Section 4.40 permits a combination of up to three attached or detached additional residential units on residentially or rurally zoned lots, for a maximum of four dwelling units in all, with a single-detached, semi-detached or townhouse dwelling on a lot that fronts an open, year-round maintained road. A unit needs independent access to the outside, and a connection to municipal water and sewer unless the Town is satisfied the Building Code is met. At most two accessory buildings may hold units, with no more than two units in each, and a detached unit's building is limited to 7.5 metres or the main building's height, whichever is less.

The by-law bars additional units on lands subject to natural hazards, such as flooding, erosion or unstable soils, unless the Conservation Authority permits otherwise. The Town requires a zoning certificate before a residential building permit, and its secondary suite page lists what a permit application shows. A general permission does not make an existing basement apartment lawful; the zoning certificate, the building permit and inspections are the records that do.

• Zoning By-law: the Town's page with the consolidated by-law, the zoning map and its parking memos
• Zoning By-law 2010-040, consolidated April 2026: section 4.40 on additional residential units (PDF)
• Secondary Suite (Additional Residential Unit): the Town's page on the zoning certificate and the building permit for a suite

Extra units allowed is in the free check as a summary of the Town's rule, from our hand-kept table of city rules, and the full report reads the lot's zone where the Town's zoning map is open data we can use; where it isn't, the report's line says where the Town 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