Garden suites & ADUs · Ajax

Garden Suites in Ajax

Ajax calls a garden suite a detached accessory dwelling unit: one unit in an accessory building on a residential lot.

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The rules, in plain language

What Ajax allows

Under Section 4.4 of the Ajax Zoning By-law (March 2026 consolidation, as amended by By-law 23-2025), a lot can have one detached accessory dwelling unit where the zone permits it. Combinations of up to two attached units plus one detached unit are allowed.

Where allowed

  • One per lot, where the main building is a detached house, semi, linked villa, street townhouse or block townhouse.
  • Not on hazard lands identified by the conservation authority, including flood and erosion limits.
  • In the Greenbelt Plan Area, it must meet the Minimum Distance Separation formulae.
  • Source: Ajax Zoning By-law, Section 4.4.2, as of November 1, 2026

Size and placement

  • Ground floor area must be less than the main house's ground floor area.
  • At least 3.0 m from any other building on the lot.
  • It must meet the accessory building standards in the by-law for height and setbacks.
  • Source: Ajax Zoning By-law, Section 4.4.2, as of November 1, 2026

Access and parking

  • An unobstructed path at least 1.2 m wide connecting to a driveway, street or lane.
  • It must comply with the by-law's parking requirements.
  • Source: Ajax Zoning By-law, Section 4.4.2, as of November 1, 2026
Check with the city: Ajax applies its general accessory building height and setback standards to detached units. We haven't listed those numbers here, so confirm them for your zone. Parking counts, fees and development charges also need checking with Ajax Planning and Building.

How we build it

Five ways to build in Ajax

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 layouts
02

Modular / prefab

Factory-built modular garden suites and backyard homes, with sizes adjustable to your lot and local rules.

Browse the model gallery
03

Custom stick-built

Framed on site for tight, sloped or oddly shaped lots, or a layout no catalogue covers.

How custom works
04

The Suite

Our own two-bedroom, two-bath concept with a covered porch. Concept design.

See The Suite
05

The Bunkie

A compact backyard suite for a home office, guest room or studio.

See The Bunkie

Every design still has to fit Ajax's zoning for your lot. We check that before you commit.

Finished Geohaus garden suite (partner build)
Finished Geohaus garden suite (partner build)
Geohaus garden suite (partner build)
Geohaus garden suite (partner build)
Geohaus garden suite (partner build)
Geohaus garden suite (partner build)
The Bunkie, a recent backyard build
The Bunkie, a recent backyard build
The Bunkie, a recent backyard build
The Bunkie, a recent backyard build
The Bunkie, a recent backyard build
The Bunkie, a recent backyard build

Common questions

Ajax garden suite FAQ

Can I build a garden suite in Ajax?

Yes, one detached accessory dwelling unit per lot where the zone permits it.

How big can it be?

Its ground floor must be smaller than the main house's, and it must meet the accessory building standards.

How far from the house?

At least 3.0 m from any other building on the lot.

Sources

Official city sources

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.

Office

258 Springbrook Ave, Ancaster, ON L9G 3K9