Tiny Homes Northumberland

Hamilton Township is a rural municipality and historic farming community known for its hamlets on the beautiful shores of Rice Lake.

As a rural community, Hamilton has no wastewater facilities, and only portions of the township have municipal water services, so most development will require a private well and all development will require private wastewater (i.e., septic) systems; check with municipal Planners to determine whether water servicing is available on your lot, and whether they will permit a composting toilet and/or rainwater recycling.

The most important aspect of this lack of municipal servicing is that the Planning Act’s as-of-right ability to build an ADU only applies in serviced areas. Since there are no fully serviced areas in Hamilton Township, you can only have an ADU in areas explicitly mentioned in the Zoning By-Law.

It’s also important to check if your property falls within the Oak Ridges Moraine, in which case it will have specific provisions to consider: see our info on the Oak Ridges Moraine. And being an agricultural community, it’s likely that any development is within sight of an active agricultural operation, so Minimum Distance Separation formulae might apply: see info on MDS here.

Zoning

The zoning for Hamilton Township seems relatively complex at first glance, with 30 different zones; that said, most of the zones themselves are relatively simple, and most of those that are not explicitly for residential use allow a single detached dwelling as accessory use. Six zones are specific to the Oak Ridges Moraine, which does not allow for ADUs. Check out the Zoning Map to determine which zone your property is in.

Section 5 of the Zoning By-Law has all of the general provisions that apply in all zones; for our purposes 5.25 is particularly important, dealing with accessory structures. It specifies that all accessory dwellings will be to the rear of the primary dwelling, so no ADUs are possible in a front yard in any zone. It also specifies that an accessory building cannot be built before the primary building, so the main house must be built before the ADU.

Section 5.35(o) notes that 2 parking spaces are required, either on site or on another designated lot within 60 meters, for each residential dwelling unit. See 5.35.2 for specific dimensions of parking spaces. However, an ADU requires only one parking space (see below under 5.44).

Garden Suites

In the era before we were all talking about ADUs, the Planning Act had a specific definition of a Garden Suite that we still find reflected in many zoning by-Laws. Section 5.38 defines Garden Suites as a complete and self-contained living unit having its own entrance and a floor area between 49 and 65 sq m (527-699 sq ft). It must be at least 4.5m from the rear lot line and 4.5m from the main dwelling, must be behind the main dwelling, must share water and wastewater services with the main dwelling, and the occupants of the garden suite must be related to the occupants of the main dwelling. It must have access from the driveway, and must be in a Temporary Zone and can stay for no more than 10 years. Note that accessory dwellings are noted as permitted in most zones, and are not defined there as being “garden suites,” so for the most part we can treat the “Garden Suite” section as an artifact of a past era: if you don’t already have a Garden Suite as defined here, then it’s probably best not to call your ADU a Garden Suite.

5.44 Additional Residential Units

It’s common to see ARU (additional residential unit) and ADU (additional dwelling unit) used interchangeably; this website uses ADU, but the Hamilton Township zoning by-law uses ARU in Section 5.44, with extensive description of ARUs and related regulations. We will continue to use “ADU” to be consistent here, but note that it means the same thing. Please read this section of the by-law in full and be sure to connect with Planners for any questions, but for now here’s a short summary:

• ADUs can only be accessory to a single-detached or semi-detached home (it can’t be accessory to a commercial or other building) and can include up to one residential unit inside a principal dwelling (e.g., a basement suite), and one outside as an accessory building (e.g., a tiny home);
• ADUs are not allowed in Limited Service Residential (LSR), Waterfront Residential (WR), or any Oak Ridges Moraine zone.
• An external ADU can be connected to the same water and wastewater services as the principal unit, provided that it is approved by the relevant authority (e.g., septic systems are regulated at the County level and sized according to the number of people using them, so adding another dwelling to the system must be approved);
• An external ADU must be clearly accessory to the principal building (i.e., it must be notably smaller);
• One parking space per ADU is required, in addition to the two spaces required for the principal dwelling;
• External ADUs must be set back 1.2m (4ft) from the principal dwelling on the lot;
• The minimum size is set by the Ontario Building Code, which specifies 17.5 sq m;
• The maximum size of an external ADU is 98 sq m (1,055 sq ft);
• Where there’s an existing Garden Suite, as defined above, it will be considered an external ADU (and therefore another external ADU won’t be permitted)

Now let’s check out each of the zones in the order they appear in the by-law. We’ll skip any that don’t allow for ADUs.

Specific Zones

Estate Residential zoning is for subdivisions in the rural area that were built before planning regulation prevented that density of development in areas that don’t have water and wastewater services; only two neighbourhoods in Hamilton Township are zoned Estate Residential, and no new neighbourhoods of that type will be created. Aside from that distinction, the ER zoning is virtually identical to any other low-density residential zone: you can build a single detached dwelling (with a minimum floor space of 150 sq m, or 1614 sq ft!), and an accessory dwelling (with no minimum footprint) at least 3 meters from the rear and side lot lines (or 15m if you have a corner lot).

Rural Residential zoning is for parts of the rural area that have small clusters of homes that are not on farmland. This zone allows for single detached dwellings with a minimum footprint of 89 sq m (958 sq ft), though if you want a smaller footprint you can spread that floor area over two storeys of half the size. It also allows for an accessory dwelling with no minimum footprint, at least 3m from the rear and side lot lines (or 20m if you have a corner lot).

Urban Residential First Density is the most common zone in settlement areas, and allows for a primary dwelling with a minimum footprint of 100 sq m (1,076 sq ft). ADUs must be 2.5m from lot lines (10m from the side lot line if you’re on a corner). Some areas in UR1 zoning have water services, and therefore have a smaller lot (98 ft of frontage) compared to lots serviced by a private well (150ft of frontage); remember that if you’re on private water services you’ll need to ensure that you have capacity to service an ADU in addition to the primary dwelling from the same well.

Urban Residential Second Density is for higher-density development in the settlement areas, allowing semi-detached and duplex dwellings with a minimum footprint of 100 sq m (1,076 sq ft) for a single detached and 180 sq m (1,937.6 sq ft) for a semi-detached or duplex building. An ADU must be in the backyard, and must be 15m (49.2ft) from side and rear lot lines if in or abutting a residential zone, less if neighbouring properties are non-residential.

Urban Multiple Residential is the zone for multi-unit residential buildings, limited to three units per building. An ADU is allowed in the backyard at least 2.5m from lot lines (or 10m from the side lot lines on a corner lot).

Commercial zones allow an accessory dwelling as an apartment in (typically above) the commercial building. Rural Commercial (RC) and Rural Highway Commercial (RHC) also allow a detached dwelling that is accessory to the commercial building. The accessory dwelling is for the owner or operator of the business.

Agricultural zones (Permanent Agriculture and Marginal Agriculture)allow for a single detached dwelling and ADUs (subject to the rules of 5.44, above). ADUs must be 10m from the lot lines (20m from the side lot lines on a corner lot).