Garden suites & ADUs · Whitby
Garden Suites in Whitby
Whitby calls a garden suite a detached additional dwelling unit (ADU): a self-contained unit in an accessory structure that is secondary to the main house.
The rules, in plain language
What Whitby allows
Whitby's By-law 8143-24 sets the standards for an additional dwelling unit in an accessory structure. Whitby has more than one zoning by-law, so the town recommends a Planning Inquiry to confirm what applies to your property.
Size and height
- Maximum gross floor area 75 m².
- Maximum height 5.5 m.
- The structure is excluded from maximum lot coverage and floor space index.
- Source: By-law 8143-24, as of November 1, 2026
Setbacks
- Interior side yard: 1.2 m.
- Rear yard: 1.2 m.
- Exterior side yard: 3.0 m.
- All other accessory structure standards still apply.
- Source: By-law 8143-24, as of November 1, 2026
Access and limits
- An unobstructed path at least 1.2 m wide and 2.1 m high to a street or lane.
- Not allowed on hazard lands, Environmental Protection, Natural Heritage System or Hazard Land designations.
- Oak Ridges Moraine and Greenbelt lots have separate, tighter rules.
- Source: By-law 8143-24, as of November 1, 2026
Check with the city: By-law 8143-24 amends one of Whitby's zoning by-laws. Confirm through a Planning Inquiry that these standards apply to your lot. Parking, fees, servicing and development charges aren't stated in these sources.
How we build it
Five ways to build in Whitby
01
Geohaus factory-built
Perimeter Homes is a Geohaus partner. Studio, one- and two-bedroom layouts built in a factory and set on your lot.
See the Geohaus layouts02
Modular / prefab
Factory-built modular garden suites and backyard homes, with sizes adjustable to your lot and local rules.
Browse the model gallery03
Custom stick-built
Framed on site for tight, sloped or oddly shaped lots, or a layout no catalogue covers.
How custom worksEvery design still has to fit Whitby's zoning for your lot. We check that before you commit.
Common questions
Whitby garden suite FAQ
How big can a garden suite be in Whitby?
75 m² gross floor area (By-law 8143-24).
How tall?
5.5 m.
How close to the lot lines?
1.2 m from the interior side and rear lot lines, 3.0 m from an exterior side.
Sources
Official city sources
- Whitby By-law 8143-24 (as of November 1, 2026)
- Town of Whitby: Additional Dwelling Units (as of November 1, 2026)
This guide summarizes public city information and isn't planning or legal advice. Rules change. Confirm your lot with the city before you apply.
Start here
Talk to a garden suite builder.
Tell us about your lot and which option you're considering. We reply within one business day.