Southwest Middlesex 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 · Southwest Middlesex’s term: “second dwelling unit”

Where a single unit or semi-detached dwelling is permitted, one second dwelling unit is allowed either inside the dwelling or in an accessory building. In an accessory building it may not exceed 75 m², and it must meet the accessory building rules. The accessory-use table lists the second dwelling unit in the R1, R2, HR and RR zones. [1]

Maximum size: Second dwelling unit in an accessory building shall not exceed a floor area of 75 m² (s.4.22 b) ii) [1]
Maximum height: Residential zones: accessory buildings shall not exceed 4.5 m in height or contain more than two storeys (s.6.3.2 h) [1]
Where allowed: Second dwelling unit listed as accessory use in R1, R2, HR and RR zones (s.6.1.2); s.4.22 applies wherever a single unit or semi-detached dwelling is permitted [1]
Number allowed: One second dwelling unit (s.4.22) [1]
Servicing: In a settlement area, must connect to municipal water and sanitary sewage where available; otherwise approved private sewage system, and a private well must produce at least 18.9 L/min (s.4.22 b) [1]
Parking: Minimum one dedicated parking space (s.4.22 b) vi) [1]
Setbacks: Residential zones: not in front or exterior side yard, at least 0.5 m from lot lines and 1.0 m from the main building; max 10% lot coverage (s.6.3.2) [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. [2][3][4]

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 with limits · Southwest Middlesex’s term: “single unit dwelling”

The zone standards set a minimum dwelling floor area of 100 m² in R1(1), 75 m² in R1(2), 90 m² in R1(3), 100 m² in HR and RR, and 100 m² in the A1 and A3 agricultural zones. [1]

Minimum dwelling size: Minimum floor area of a dwelling: R1(1) 100 m², R1(2) 75 m², R1(3) 90 m², LR 75 m², HR 100 m², RR 100 m² (s.6.2.1) [1]
Minimum dwelling size: A1 and A3 zones: minimum floor area of a dwelling 100 m² (s.5.2.1) [1]

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. [2][5][6][7][8][9][10]

Tiny home on wheels or park model

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

Allowed with limits · Southwest Middlesex’s term: “mobile home / travel trailer”

Mobile homes are prohibited in any zone except where specifically permitted. They are listed only in the Lifestyle Residential (LR) zone and a site-specific mobile home park zone (OS-5), and the by-law defines a mobile home as a CSA Z240 unit on a full concrete foundation. Using a travel trailer, truck camper or motor home for living or sleeping is prohibited, and some temporary use by-laws have allowed trailers or garden suites on specific properties. [1]

Where allowed: Prohibited in any zone except where specifically permitted: a mobile home; use of any travel trailer, truck camper or motor home for living, sleeping or eating (s.4.19) [1]
Where allowed: Mobile home permitted in Lifestyle Residential (LR) zone (s.6.1.1); mobile home park (max 22 mobile homes) at Jefferson Junction Family Campground, OS-5 (s.9.5.5) [1]
Temporary garden suite: Granted site-specifically by temporary use by-law, e.g. By-law 2016/067 (mobile home garden suite, max 20 years) and By-law 2021/079 (garden suite), per the temporary use by-law table [1]

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. [10][5][2][7][6]

Bunkie or sleeping cabin

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

Not allowed · Southwest Middlesex’s term: “accessory building”

The by-law does not provide for sleeping cabins or bunkies. Accessory buildings may not be used for human habitation except for a second dwelling unit, and the general definition of accessory excludes human habitation unless otherwise specified. [1]

Where allowed: Accessory buildings shall not be used for human habitation except as otherwise permitted herein for a second dwelling unit (s.6.3.2 a); 'accessory' means not used for human habitation unless specified otherwise (s.2.2) [1]

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. [7][5][2][11]

Official links

Last confirmed October 2026.

Notes and caveats

The consolidation includes amendments adopted before 20 March 2026. The by-law number is 2011/065 (spelled '2011/65' in the amendment table). Second dwelling unit provisions (s.4.22) date from By-law 2015/066 and still allow only one additional unit. No three-unit Bill 23-style update appears in the consolidation. The LR zone description says no lifestyle community developments exist in the municipality. Zone permission checkmarks were read from rendered page images of the PDF.

Sources

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Southwest Middlesex 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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