Trent Hills zoning for small homes

Municipality of Trent Hills, in the County of Northumberland. Population 13,861 (2021 census).

Backyard suite

A separate home in the yard of a house: garden suite, laneway suite or coach house, including prefab, modular or container units used this way.

Allowed · Trent Hills’s term: “additional residential unit”

Up to two additional residential units per primary dwelling are permitted, including in a separate accessory building, in the RU, A, RR, SRR, SR, R1, R2 and R3 zones. They are not permitted on private roads, next to lakes with limited lake capacity, in flood-prone or Environmental Protection areas, or on a lot with a garden suite or bunkie. [1]

Where allowed: RU, A, RR, SRR, SR, R1, R2, R3 zones (Table 1, June 2025 consolidation) [2]
Number allowed: Maximum of two additional residential units per primary dwelling unit (s.5.27 a) [3]
Maximum height: An ARU in an accessory building may not exceed the maximum height of the primary dwelling on the property (s.5.27 n); accessory buildings generally max 8 m (s.5.1 d) [3]
Setbacks: Accessory buildings: not closer than 1.2 m to an interior side or rear lot line (s.5.1 i); total coverage of accessory buildings max 15% of lot area; in R1, R2 and R3 total coverage of all structures max 45% where an ARU is in an accessory building (s.5.27 l) [3]
Separation from house: Accessory buildings not closer than 1.5 m to the principal building (s.5.1 c) [3]
Parking: No separate driveway; a tandem space within the primary dwelling's driveway may meet the parking requirement (s.5.27 d) [3]
Servicing: In rural areas, subject to potable water and septic systems that serve the additional unit (s.5.27 c) [3]
Approvals: Building permit required; Building Code and Fire Code apply (s.5.27 j) [3]

Ontario-wide rule

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. [4][5][6]

Tiny home on a foundation

A small house as the main home on its own lot. The key rule is any minimum dwelling size.

Allowed · Trent Hills’s term: “single detached dwelling house”

Section 5.5 i) sets the minimum gross floor area of a dwelling in any residential zone as the minimum required by the Ontario Building Code, and Table 2 refers each zone's minimum gross floor area to that rule. A dwelling house must be permanently affixed. [7]

Minimum dwelling size: "The minimum gross floor area of a residential dwelling in any residential zone shall be the minimum gross floor area as required by the Ontario Building Code" (s.5.5 i); Table 2 row 'Minimum Gross Floor Area per Dwelling Unit' refers to the OBC for all zones [3]

Ontario-wide rule

Ontario law sets no minimum total size for a house that is the main dwelling. The Building Code sets minimum room areas, so the smallest compliant dwelling is roughly 17.5 m² by the Province's own estimate. Municipalities may still set minimum floor areas for main dwellings in their zoning by-laws. The provincial ban on minimum sizes covers only additional residential units. [4][8][9][10][11][12][13]

Tiny home on wheels or park model

Living full-time in a tiny home on wheels or a park model home.

Allowed with limits · Trent Hills’s term: “mobile home / park model trailer / travel trailer”

A dwelling house excludes travel trailers, mobile homes and recreational vehicles. No trailer or similar structure may be used for human habitation, whether or not it is on wheels. Table 1 lists 'Mobile Home/Trailer Park' only in the Recreational Commercial (C4) zone.

Where allowed: 'Mobile Home/Trailer Park' is a permitted use in the C4 (Recreational Commercial) zone only (Table 1) [2]
Approvals: "No truck, bus, coach, trailer, street car body, shipping container or structure of any kind, other than a structure erected and used in accordance with this By-law, the Ontario Building Code ... shall be used for human habitation, whether or not the same is mounted on wheels" (s.5.1 r) [3]

Ontario-wide rule

Ontario has no single rule for living full-time in a tiny home on wheels. A unit on wheels can count as a 'building' that needs a permit and must meet the Building Code once it stays in one place, is hooked up to services or is anchored. Park model trailers are recognized only as seasonal recreational buildings. Municipalities may allow a portable garden suite under a temporary-use by-law for up to 20 years, with extensions of up to 3 years each. [13][8][4][10][9]

Bunkie or sleeping cabin

A small sleeping building with no kitchen, usually beside a cottage or house.

Allowed with limits · Trent Hills’s term: “bunkie”

A bunkie is a detached accessory sleeping building that may have sanitary facilities but no cooking facilities. The by-law expressly provides for one in the Shoreline Residential (SR) zone on lots abutting a navigable waterway, up to 75 m². Elsewhere, accessory buildings may not be used for human habitation unless specifically permitted. A bunkie and an additional residential unit may not be on the same lot.

Where allowed: In the required yard of a lot abutting a navigable waterway within the Shoreline Residential (SR) Zone, not within the EP zone (s.5.1 g) [3]
Maximum size: 75 m² total floor area [3]
Kitchen: Sanitary facilities may be provided, but no cooking facilities (definition 4.36) [3]
Maximum height: Accessory buildings max 8 m (s.5.1 d) [3]
Number allowed: Not stated; an additional residential unit is not permitted on a lot with a bunkie (s.5.27 i) [3]

Ontario-wide rule

Ontario law has no rule written specifically for bunkies or sleeping cabins. Whether one needs a building permit depends on the Building Code Act's definition of 'building' and the Code's shed exemption. That exemption covers only storage-use sheds, so it does not cover a structure used for sleeping. Municipal zoning rules for accessory buildings still apply. [10][8][4][14]

Official links

Last confirmed October 2026.

Notes and caveats

Main text is the March 2026 office consolidation, though its amendment list is headed 'Updated June 2025'. The tables are separate PDFs with their own dates: Table 1 June 2025, Table 2 March 2026, Table 3 July 2026 (https://www.trenthills.ca/business-development/planning-and-zoning/zoning/). Conflict: s.18.4 (R2 zone) still sets a minimum floor area of 54 m² for a non-bachelor dwelling unit (36 m² bachelor), but s.5.5 i) and Table 2 defer to the OBC for all residential zones. s.5.27 refers to 'Section 5.24' and s.5.1 to 'Section 5.24' for second units, which look like stale cross-references. 'Garden suite' appears only in s.5.27 i); no temporary garden suite (s.39.1) provisions were found. Housekeeping amendment C02/2026 was not checked. No ARU guide found.

Sources

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