Cambridge zoning for small homes

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 · Cambridge’s term: “detached additional residential unit (ARU)”

One detached ARU is permitted on a lot with a single detached, semi-detached or street townhouse dwelling on urban residential land, as long as it meets the standards in Section 4.19 of By-law 26-007. Up to two ARUs are allowed per lot, and no more than one of them may be detached. [1]

Number allowed: Maximum two ARUs per residential lot: two attached, or one attached and one detached (s. 4.19(d)) [2]
Maximum size: Maximum lot coverage of the lesser of 100 m² or 15% (s. 4.19.2(d)) [2]
Maximum height: 4.5 m on lots under 21 m frontage not accessed by a lane; 6.0 m on lots with 21 m+ frontage if set back 3 m from all lot lines and 6 m from the main dwelling, or where accessed by a lane / on a through lot (s. 4.19.2(c)) [2]
Setbacks: 1.2 m from interior side and rear lot lines (0.6 m from the rear/lane line on lane-accessed or through lots); exterior side yard same as for the main dwelling (s. 4.19.2(a)) [2]
Separation from house: Minimum 4.5 m from the principal dwelling (s. 4.19.2(b)) [2]
Parking: One additional space per ARU, which may be tandem; no new driveway allowed for an ARU (s. 4.19(f)) [2]
Servicing: Must connect to municipal water and sewer where available; otherwise, proof that on-site services can handle the house and the ARU(s) (s. 4.19(g)) [2]
Where allowed: Not in the Floodway (F) Zone or any Floodplain Overlay Zone; entrance no more than 30 m from the street unless accessed by a lane that meets Fire Access Route requirements; 0.9 m wide unobstructed path from the street required (s. 4.19(h),(i), 4.19.2(e)) [2]
Approvals: Building permit required; occupancy must be approved by Building Services [1]

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. [3][4][5]

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 · Cambridge’s term: “single-detached dwelling”

By-law 26-007 sets no minimum dwelling floor area for single-detached dwellings in the RR, R1 or R2 zones; Table 7.3A regulates lot size, yards, height and landscaping only. Deferred lands still under By-law 150-85 do have minimum floor areas (see notes).

Minimum dwelling size: None in By-law 26-007 Table 7.3A (RR, R1, R2 detached dwelling standards) [2]
Minimum lot size: RR zone: 2,000 m² lot area and 30 m frontage; R1: 15 m frontage; R2: 9.0 m frontage (Table 7.3A) [2]

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. [3][6][7][8][9][10][11]

Tiny home on wheels or park model

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

Not allowed · Cambridge’s term: “trailer / mobile home dwelling”

Using a tent, trailer or motor vehicle for human habitation is prohibited in every zone, except in a campground, trailer park or mobile home park that the by-law expressly permits. Neither By-law 26-007 nor By-law 150-85 permits such a park in any zone. [12]

Where allowed: s. 4.26(a), By-law 26-007: trailer or motor-vehicle habitation is prohibited except in an expressly permitted campground, trailer park or mobile home park; no such zone was found [2]
Temporary garden suite: No general provision. In the past, garden suites were allowed site-by-site through temporary use by-laws under By-law 150-85 (e.g. s. 4.3.8, 4.3.9, 4.3.11, all now expired). Part 16 (Temporary Uses) of By-law 26-007 is reserved. [12]

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. [11][6][3][8][7]

Bunkie or sleeping cabin

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

Not allowed · Cambridge’s term: “accessory building”

No accessory building or structure may be used for human habitation unless the by-law expressly permits it, and no bunkie or sleeping cabin use is provided for. A detached unit used for living must meet the detached ARU rules. [12]

Where allowed: s. 4.1(b) and 4.26(b), By-law 26-007: accessory buildings may not be used for human habitation unless expressly permitted. By-law 150-85 s. 3.1.1 has a similar rule. [2]

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. [8][6][3][13]

Official links

Last confirmed October 2026.

Notes and caveats

Two by-laws apply. By-law 26-007 was enacted 2026-02-03 and covers residentially zoned lands. By-law 150-85 still covers deferred residential areas and all non-residential zones, including the A1 agricultural zone. The posted 150-85 PDF is a January 2012 consolidation, so later amendments are not in it, including the ARU By-law 23-077 named on the City's ARU page. Under 150-85 residential tables, single-detached dwellings have a minimum gross floor area of 75–120 m² depending on zone (RR1, RR2, R1–R6, RS1, etc.); this still applies on deferred lands. 150-85 also prohibits tents and trailers as living accommodation (s. 2.1.2). The 26-007 PDF is the certified enacted version, not a consolidation.

Sources

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Cambridge zoning for small homes

Backyard suite

Ontario-wide rule

Tiny home on a foundation

Ontario-wide rule

Tiny home on wheels or park model

Ontario-wide rule

Bunkie or sleeping cabin

Ontario-wide rule

Official links

Sources

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