Tiny Homes Northumberland

The Municipality of Trent Hills features the town of Campbellford, Ferris Provincial Park, the villages of Hastings and Warkworth, and numerous small hamlets along the Trent River.

Official Plan

The Trent Hills website has a form for development inquiries, which is the best way to connect with Planners to discuss your plans for your property. Their Official Plan (OP) is currently under review, so expect this page to change in 2025. In the meantime, Trent Hills has produced discussion papers that help frame the process of developing a new OP. The most relevant of these for our purposes is the first, “Building Strong Healthy Communities“, which includes:

• 2.1.3 an acknowledgement of the Planning Act‘s requirement that municipalities take steps to ensure that there’s sufficient affordable housing in the community;
• 2.1.4 a discussion of recent changes to the Planning Act that allow up to two ADUs “as of right” (i.e., no matter what local zoning allows) in residential zones that are fully serviced with municipal water and sewer, including one additional unit in the main house and one in an “ancillary” building (e.g., a converted garage or a detached tiny home);
• 2.1.5 noting that the Planning Act requires that Official Plans include goals for addressing climate change and improving local resiliency;
• Section 2.2 which acknowledges the Provincial Planning Statement (PPS) 2020. While this has since been surpassed by the PPS 2024, the new PPS still promotes the same principles of sound planning including ensuring efficient land use including increasing density (sometimes called “intensifying”) in urban areas before expanding urban boundaries, which allows for better protection of farmland and wild areas;
• The PPS’s discussion of intensification through ADUs, and their role in promoting affordable housing, defining affordable as housing costing no more than 30% of household income for households in the bottom 60% of the income spectrum;
• Section 2.4 reviews the requirements of the Growth Plan for the Greater Golden Horseshoe (now incorporated into the PPS 2024), which among other things emphasizes supporting a diverse mix of housing options specifically including ADUs;
• Section 2.8 discusses the Northumberland County Affordable Housing Strategy, notes that Trent Hills has almost exclusively single-detached dwellings, and mentions that Trent Hills needs more affordable housing and specifically more options for smaller households;
• Section 2.9 outlines and explores the implications of the Northumberland County Housing and Homelessness Plan, including encouraging the development of a diverse housing supply;
• Section 2.12 discusses the results of a public survey to support the development of the new Strategic Plan, in which the public identified a need for more diversity and affordability of housing;
• Section 3.3 identifies Campbellford as having the highest proportion of single-detached dwellings in the County, making it a prime place for adding density and diversity of housing through ADUs;
• 4.3.3 recommends specific policies for ADUs in the new Trent Hills OP, including defining different types of ADUs (Garden Suites, Coach Houses, Tiny Homes, etc) and recommending that only 1 additional parking space be required per ADU.

While the Trent Hills Official Plan cannot be completed until Northumberland County completes their OP revisions, the guidance provided by these discussion papers gives a good sense of what the new OP will eventually include. Trent Hills’ Planning staff have already begun implementing some of these ideas, recently permitting a small modular home to be built on a tiny lot in Campbellford, suggesting that they are embracing the spirit of OP reform even as the process itself is held up. Given that, it’s worth a discussion with Planners even if you are concerned that the existing zoning by-law wouldn’t allow you to build an ADU.

Zoning By-Law

The Zoning By-Law is still based on the 2001 Official Plan, so expect it to change as the new OP is developed, likely in 2025. In the meantime, the existing by-law was first adopted in 2010, amended several times, and consolidated in August 2024.

Definitions

• 4.4.1 defines an Additional Residential Unit (or ARU, a term commonly used interchangeably with Additional Dwelling Unit, or ADU) as and ancillary (i.e., supporting or in addition to the primary) unit, either in the same building (detached, semi-detached, or townhouse) as, or in a detached building on the same lot as, the primary dwelling;
• 4.32 defines a bunkie as a detached accessory building that includes a sleeping area and may include a washroom but does not include cooking facilities (note that cooking facilities are needed in all permanent dwellings, so a bunkie cannot be an ADU);
• 4.64 defines a dwelling house as a structure, either built on site or prefabricated (as most tiny homes are) but not including mobile homes or camping trailers, for the purpose of living in;
  • A dwelling unit is defined as a space within a building that has its own access, living spaces, cooking spaces, and sanitary services (e.g., bathroom). This might be in a multi-unit building like an apartment building, or one unit of a semi-detached or duplex or townhouse, etc. The definition here notes that an ADU is allowed to have access from inside another unit (e.g., entering the building through a shared space before entering a basement unit);
  • Various types of dwellings are described, including single detached, semi-detached, duplex, triplex, fourplex, row housing, apartments, and variations on the above.
• 4.162 defines a mobile home as a transportable, factory-built home that is not a park model trailer, complying with CSA standard Z240 M.H. (so long as your tiny home is not built to this standard it should not be considered a mobile home);
• 4.195 defines a park model trailer as a recreational unit mounted on a chassis and wheels and designed for camping, not exceeding 50 sq m in size, and complying with CSA standard Z241 or its successor (so long as your tiny home is not built to this standard it should not be considered a park model trailer);
• 4.202 defines partial servicing as a dwelling connected to a combination of on-site water or sewer (e.g., a well or septic system) with a communal or municipal water or sewer system;
• 4.238 defines second units as “private, self-contained residential units with kitchen and bathroom facilities and sleeping areas within detached, semi-detached or row houses or within ancillary structures such as garages or coach houses.” This definition is more or less the same as that of additional residential units above, and probably used interchangeably.

General Provisions

The following regulations are relevant to the matter of ADUs, and are not zone-specific:

• Section 5.1 holds that:
  • an ADU is allowed in the second storey of an accessory building (e.g., a garage) in any Residential or Rural zone;
  • accessory structures have the same setback requirements as the main house in all Residential zones (i.e., you can’t put a tiny home in the front yard);
  • accessory buildings must be at least 1.5m from the main building;
  • all structures combined cannot cover more than 15% of the lot;
  • accessory buildings must be at least 1.2m from all side or rear lot lines;
  • if there’s an existing home in a Residential zone that is set back well beyond the minimum front yard, it’s allowable to add an accessory building between the house and the road provided it still meets the setback requirements for that zone;
• Section 5.3 notes that no basement suites will be allowed to be lower than the septic or sewer system, or if the basement floor is more than 0.6m below the adjacent finished grade unless it is on municipal services (we interpret this to mean that basement suites in homes on private septic systems aren’t allowed, but check with the Planner);
• Section 5.5.i notes that the minimum footprint of all dwellings in this by-law is whatever standard is set by the Ontario Building Code – which is to say, tiny homes are just homes that happen to be small!
• 5.19 describes the Minimum Distance Separation (MDS) formulas that apply when building an ADU near an existing livestock barn–see our explanation of MDS here;
• 5.22 details parking requirements (recall the note in the OP discussion papers above that it is recommended that each ADU only require 1 parking space) — be sure to understand how much space is required for your parking space (generally one per dwelling unit for most common housing types);
• 5.27 details regulations on all additional residential units, including:
  • They are permissible in detached, semi-detached, and row housing, or in detached buildings accessory to them;
  • Maximum of two ADUs per primary dwelling;
  • An ADU is “ancillary to the primary dwelling unit on the property” (i.e., the ADU is smaller than the primary dwelling);
  • Rural ADUs are subject to water/wastewater systems having capacity for them;
  • ADUs are not allowed a separate driveway;
  • ADUs are not allowed in flood plains, even if there is already a house there;
  • ADUs are not allowed on private roads;
  • ADUs are not allowed in areas adjacent to lakes with limited lake capacity;
  • ADUs are not allowed on lots that already have a Garden Suite, Bunkie, or other extra rooming;
  • A building permit is required for an ADU, which must meet the Ontario Building Code and Fire Code requirements;
  • An ADU cannot be taller than the primary dwelling.

Zones

Of the 24 zones in Trent Hills’ Zoning By-Law, ADUs are only allowed in 7: Rural (RU), Rural Residential (RR), Special Rural Residential (SRR), Shoreline Residential (SR), Residential Type 1 (R1), Residential Type 2 (R2), and Residential Type 3 (R3) zones.

There are no special requirements for ADUs in each of these zones other than what is noted above. Rules for setbacks, parking, and servicing for a given zone apply to ADUs on the property in the same way as the primary dwelling, unless otherwise noted above.

Dwelling units in a portion of a non-residential building, such as an apartment above a shop, are possible in 7 zones: Residential Type 1 (R1), Residential Type 2 (R2), Community Facility (CF), General Commercial (C1), Highway Commercial (C2), Local Commercial (C3), and Recreational Commercial (C4) zones. There are a few qualifications on this:

• In a General Commercial (C1) zone, one or more dwellings are allowed provided they are above the ground floor — i.e., the ground floor is for commercial, but there can be residential upstairs;
• The C2 and C4 zones allow for one dwelling unit on part of the property provided that it is occupied by someone who is employed full-time at the business, such as a groundskeeper or security guard (unless the business is a motor vehicle service station, in which case no dwelling is allowed).

For a list of possible uses by zone, see Table 1.

For a list of regulations by building type and zone, such as minimum lot sizes and setbacks, see Table 2.