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Tiny Home List

Grimsby zoning for small homes

Town of Grimsby, in the Region of Niagara. Population 28,883 (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 with limits · Grimsby’s term: “additional residential unit (ARU) in an accessory building”

In the urban residential and downtown zones on lots connected to municipal water and wastewater, one ARU may be in a detached accessory building (plus one in the house); in the Hamlet Residential zone one ARU may be in an accessory building. In rural and agricultural zones a detached ARU is limited to an existing accessory building in the farm building cluster, and none is permitted in a detached building within the Niagara Escarpment Plan Area. [1]

Number allowed
Urban serviced zones: max 2 ARUs (2 in/attached to house, or 1 in house + 1 in accessory building); Hamlet Residential: 1; Rural/Agricultural: 1 (s. 4.19) [2]
Where allowed
RD1, RD2, RD3, RD4, RD5, MS, RM1, TRM, GB, GB1, ND, MHD (urban); HR (hamlet); A, RU, SC (rural, existing accessory building only) [3]
Maximum height
Residential zones: 4.5 m peaked roof, 3 m flat roof (Table 2, accessory buildings) [2]
Maximum size
Accessory buildings max 10% lot coverage in residential zones (Table 2); lots with ARUs complying with s. 4.19 may exceed the zone's lot coverage up to 45% total (Table 11 note 10) [2]
Setbacks
Residential zones: 1.3 m rear, 0.6 m interior side (1.2 m where windows face the side lot line), 6 m exterior side; at least 1.5 m from main buildings (s. 4.18 e, Table 2) [2]
Parking
One space per additional residential unit; may be tandem [3]
Servicing
Urban ARUs: principal dwelling connected to municipal water and wastewater; hamlet/rural: adequate private services [2]
Approvals
Building permit required [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 · Grimsby’s term: “single detached dwelling”

The residential (Table 11) and rural/agricultural (Table 7) zone regulations set lot, yard, coverage and height limits but no minimum dwelling floor area.

Minimum dwelling size
None set in Table 7 (rural/agricultural) or Table 11 (residential) [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. [4][7][8][9][10][11][12]

Tiny home on wheels or park model

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

Allowed with limits · Grimsby’s term: “mobile home trailer / garden suite”

Use of a mobile home trailer for human habitation is prohibited except as a garden suite or farm help-house, and trailer camps are prohibited. Garden suites (portable units ancillary to an existing residence) are listed as an accessory use only in the Agricultural and Rural zones and are not allowed on a lot with an ARU.

Where allowed
s. 4.4 a) 17: prohibited "except as a garden suite or help house"; s. 4.4 a) 16: trailer camps prohibited; garden suite permitted as an accessory use in A and RU zones (Table 6) [2]
Number allowed
Garden suites not permitted on any lot with an additional residential unit (s. 4.19 e) [2]
Parking
One space per garden suite [2]

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. [12][7][4][9][8]

Bunkie or sleeping cabin

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

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

Human habitation in accessory buildings is prohibited except where the accessory building contains an additional residential unit; the by-law has no bunkie or sleeping cabin provision.

Maximum height
Agricultural and Rural zones: 4.5 m peaked roof, 3 m flat roof (Table 2) [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. [9][7][4][13]

Official links

Last confirmed October 2026.

Notes and caveats

ARU provisions (s. 4.19) reflect amendments passed by Council on August 11, 2025, per the Town ARU page; the November 2025 consolidation includes them. The 'mobile home trailer' definition states it 'shall not be occupied continuously as a principal residence'; the by-law contains no standards for garden suites and does not say whether a Temporary Use By-law is required, so full-time year-round use of a trailer as a garden suite is not confirmed. Within the Niagara Escarpment Plan Area, ARUs are limited to the principal dwelling (Town guide).

Sources

  1. Grimsby’s guide to additional units
  2. Zoning By-law 14-45
  3. media-001-ca.cdn.govstack.com PDF
  4. Planning Act (Ontario e-Laws)
  5. O. Reg. 299/19: Additional residential units (Ontario e-Laws)
  6. Development Charges Act, 1997 (Ontario e-Laws)
  7. Government of Ontario PDF
  8. Build or buy a tiny home: Building Code requirements (Government of Ontario)
  9. Building Code Act, 1992 (Ontario e-Laws)
  10. O. Reg. 163/24: Ontario Building Code (Ontario e-Laws)
  11. 2024 Ontario Building Code (Government of Ontario)
  12. Build or buy a tiny home: permits and inspections (Government of Ontario)
  13. Building Code updates (Government of Ontario)

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