Severn zoning for small homes

Township of Severn, in the County of Simcoe. Population 14,576 (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 · Severn’s term: “additional residential unit”

One detached additional residential unit is permitted in the R1, R2, RM1, SR1, ER, RR, AG and RU zones (By-law 2026-40), but not in the SR2 and SR3 shoreline zones.

Number allowed: Maximum two ARUs; only one may be detached from the principal dwelling (s.3.3.1 d) [1]
Maximum size: Footprint not more than the lesser of 75% of the floor area of the principal building or 110.0 m² (s.3.3.2 a, 3.3.3 a) [1]
Maximum height: 5 m; 8 m if the ARU is in a half or second storey, never higher than the principal dwelling (R1, R2, RM1, ER, SR1) (s.3.3.2 b); AG/RU up to 11 m above another use in an existing building (s.3.3.3 c) [1]
Setbacks: Must meet the principal building's minimum yards for the zone; not in the front yard of a waterfront property; urban lots max 45% lot coverage (s.3.3.1 b, e, g) [1]
Separation from house: Minimum 3.0 m from any other building containing a residential unit (s.3.3.1 f); in AG, RU, RR and GL no more than 75 m from the principal dwelling (s.3.3.3 d) [1]
Where allowed: Not permitted in SR2 and SR3 zones (s.3.3.1 a); mobile home not permitted as an ARU unless expressly permitted (s.3.3.1 c) [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 · Severn’s term: “single detached dwelling”

Table 6.2 sets a minimum gross floor area of 65 m² in the R1, R2, SR1, SR2, SR3 and RR zones and 140 m² in the ER zone; the AG and RU zone table sets no minimum.

Minimum dwelling size: 65 m² (R1, R2, SR1, SR2, SR3, RR); 140 m² (ER) (Table 6.2); none in AG/RU (Table 5.2) [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 · Severn’s term: “mobile home”

Use of any motor vehicle, trailer or similar structure for human habitation is prohibited unless specifically permitted; mobile homes are a permitted use only in the Mobile Home Residential (MHR) zone (mobile home park).

Where allowed: Mobile Home Residential (MHR) zone; individual sites min 750 m², 18.0 m frontage, 30% coverage, 8.0 m height (Table 6.1, Table 6.2 note b) [1]
Temporary garden suite: A garden suite may be permitted by way of a Temporary Use By-law under the Planning Act and may be subject to an agreement with the Township (s.3.8) [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.

Allowed with limits · Severn’s term: “sleeping cabin”

A sleeping cabin (no kitchen) may be erected only in the SR2 and SR3 shoreline residential zones, one per lot.

Where allowed: SR2 (Shoreline Residential Non-Serviced) and SR3 (Shoreline Residential Restricted Access) zones (s.3.1.13) [1]
Maximum size: 45.0 m² gross floor area including porches and covered decks (s.3.1.13 b) [1]
Number allowed: One sleeping cabin per lot; not counted toward the three accessory building maximum (s.3.1.13 d, s.3.1.7) [1]
Kitchen: No kitchen or cooking facilities; sanitary facilities may be provided (s.3.1.13 c; definition 'Cabin, Sleeping') [1]
Setbacks: Must meet the minimum yard requirements for the principal use in the zone (s.3.1.13 a) [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

Consolidation version dated July 24, 2026, includes ARU By-law 2026-40. Various site-specific exceptions permit additional sleeping cabins, existing mobile homes as ARUs or garden suites. No official ARU guide found. Schedules posted separately and not checked.

Sources

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