What records explain additional residential units at a Milton home?

Section 4.10 of Zoning By-law 016-2014 permits additional units in a detached, semi-detached, semi-link or townhouse dwelling, or an accessory building on the same lot: at most three on a lot, no more than one in an accessory building, served by municipal water and wastewater (up to two where a low-density lot has no municipal services). It sets limits on the size of units above the basement and a 1.2-metre clear path to the unit's entrance, and it doesn't permit units on land a conservation authority identifies as hazard land or regulatory flood plain unless that authority permits them. The Town's page says stacked and back-to-back townhouses are excluded, and that since January 2026 rural lots may have one or two units depending on zone and whether they lie in the Niagara Escarpment Plan Area or the Greenbelt.

Since 1 April 2025, under By-law 032-2025, every additional unit in Milton, new or existing, must be registered with the Town, with no exemption for older units; the Town's page lists a fee of $340 per unit, an inspection by a municipal law enforcement officer and a fire prevention officer, and a compliance certificate renewed each year during the three-year pilot that began in 2025. A general permission does not make an existing basement apartment lawful; registration, the building permit and inspections are the records that do.

• Build an ARU: the Town's page on eligible urban and rural lots, zoning and building permits
• Register an existing ARU: the Town's page on registration, the fee, inspections and the compliance certificate
• Additional Residential Units Registry Application: the Town's form, which names By-law 032-2025
• Zoning By-law 016-2014, March 2026 consolidation: section 4.10 on additional dwelling units (PDF)

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