Perth County’s current Official Plan describes separate rules for additional residential units (ARUs) on land designated Agriculture and for Garden Suites. These policies explain the County’s planning framework. They do not establish that a specific property is zoned for a proposed unit, has an approval, or can support the necessary services.
Agriculture-designated land
The Plan permits up to two ARUs in the Agriculture designation, with no more than two in or attached to the principal dwelling and no more than one in an accessory building. Local zoning must permit the residential use in the agricultural zone. The lot must be appropriately sized and have enough long-term servicing capacity. The proposal must not harm the ability of nearby livestock operations to expand and must meet Minimum Distance Separation I requirements, or avoid making an already insufficient setback worse.
An ARU in an ancillary building must be limited in scale and placed within or near the principal dwelling, established residential area, or farm cluster. It must share a driveway with the existing residence. The County Plan also says an agricultural ARU cannot be severed from the lot containing the principal dwelling or made separately transferable through a condominium plan. That is a planning-policy restriction; it is not a title search or determination of a particular conveyance.
Garden Suites and temporary authorization
The Plan defines a Garden Suite as a portable, one-unit detached residential structure with kitchen and bathroom facilities, accessory to an existing residential structure. It counts as an ARU within the maximum number of units permitted on the lot.
The Plan says a Garden Suite may be permitted through a Temporary Use Zoning By-law Amendment for an initial term of up to 20 years, with further renewals of up to three years. The lot must be suitable for the required water supply and sewage treatment; a hydrogeological study may be required for privately serviced lots. On Agriculture-designated land, the suite must be close to the principal farm residence and farm cluster, use the existing driveway, and satisfy the MDS I policy. The lower-tier municipality may require an owner agreement on the suite’s non-permanent aspects and may create a process to convert a Garden Suite to an ARU. Neither renewal nor conversion is automatic.
What to verify for a property
The current County Plan came into effect in 2025, but each application still requires the applicable lower-tier municipality’s zoning rules and project instruments. Confirm the designation and lot facts, local zoning permission, water and sewer or septic capacity, agricultural compatibility and MDS I, access and hazard constraints, and whether a temporary-use bylaw or owner agreement exists. For a current or proposed Garden Suite, check its authorized term, renewal or removal conditions, and whether any conversion process applies.
Check the property’s registered title and approval history separately before making a transfer or occupancy decision. The County Plan’s policy summary is a useful starting point, not confirmation of planning, building, fire, title, or occupancy status for a parcel.