Armstrong zoning for small homes

What applies everywhere in Ontario

Ontario law stops municipalities from banning one residential unit in a building ancillary to a detached house, semi-detached house or rowhouse on a parcel of urban residential land, as long as the lot has no more than three units in total. Municipalities still set most other zoning rules, but provincial law limits parking requirements, minimum unit size, lot coverage and separation distances. These units are also exempt from development charges and parkland dedication. [1][2][3]

Units allowed

A zoning by-law cannot prohibit one residential unit in a building or structure ancillary to a detached house, semi-detached house or rowhouse, if the main house has no more than two units and no other ancillary building has a unit. That allows up to 3 units per lot. Official plans are under the same restriction. In force November 28, 2022 (Bill 23, 2022, c. 21, Sched. 9). (Planning Act s. 35.1(1)(c); s. 16(3)(c)) [1]

Ancillary-building limit

All buildings ancillary to the house can together hold no more than one residential unit. If the house itself has three units, no ancillary building may have a unit. (Planning Act s. 35.1(1)(a)-(c); s. 16(3)(a)-(c)) [1]

Eligible land

These protections apply to a 'parcel of urban residential land'. That means land inside a settlement area, where residential use (other than ancillary residential use) is permitted by by-law, and that is served by both municipal sewage works and a municipal drinking water system. Lots on private wells or septic systems are not covered. (Planning Act s. 1(1), definition of 'parcel of urban residential land') [1]

Parking

Municipalities cannot require more than one parking space for each additional unit (the primary unit is not counted). O. Reg. 299/19 sets one space per additional unit, which may be a tandem space. No space is needed if the by-law requires none for the primary unit. A by-law that requires no ARU parking prevails over the regulation. (O. Reg. 299/19 ss. 2-3; Planning Act s. 35.1(1.1); s. 16(3.1), as amended 2023, c. 10) [2]

Minimum unit size

A zoning by-law cannot set a minimum floor area for these units, and an official plan cannot contain a minimum floor area policy for them. (Planning Act s. 35.1(1.2); s. 16(3.2)) [1]

Lot coverage and separation (urban residential land)

Up to 45% lot coverage by all buildings is permitted. There is no floor space index limit, subject to by-law height and setback rules. A building with an ARU may penetrate angular planes. The minimum lot area is the same as if there were no ARU. A building containing an ARU must be at least 4 m from another building on the lot that contains a residential unit. A by-law allowing more coverage or less separation prevails. Added by O. Reg. 462/24, in force November 20, 2024, under the regulation power from Bill 185 (2024, c. 16). (O. Reg. 299/19 ss. 4-5) [2]

Occupancy

Anyone may occupy an additional unit, whether or not they are related to the occupant of the primary unit and whether or not either occupant owns the lot. An ARU is permitted regardless of when the primary house was built. (O. Reg. 299/19 s. 2, paras. 4-5) [2]

Appeals

No one can appeal official plan policies or the parts of a zoning by-law that authorize these units. This covers any parcel where residential use is permitted. (Planning Act ss. 17(24.1), 17(36.1); s. 34(19.1)) [1]

Development charges

Creating one unit in a building ancillary to an existing or new detached house, semi-detached house or rowhouse is exempt from development charges, within the same 3-unit limits. In force November 28, 2022, amended June 8, 2023. (Development Charges Act s. 2(3.2) para. 3; s. 2(3.3) para. 3) [3]

Parkland

A parkland dedication by-law does not apply to putting up one residential unit in an ancillary building, within the same 3-unit limits. (Planning Act s. 42(1.3)(c)) [1]