Ajax deck permits · Reformity Inc.Deck Permit Drawings in Ajax
Plan on one: decks are one of Ajax's listed building permit types, and Ontario's Building Code Act treats any structure over 10 m² with a floor as a building that needs a permit. The Town publishes no smaller exemption, so we confirm small, low decks with Ajax Building Services.
We prepare and submit your permit drawings to the Town of Ajax, then build to the approved plan.
Do you need a permit?
Deck permit rules in Ajax.
Whether the house is on central Ajax's postwar streets or in early-1980s Westney Heights, zoning treats a deck as a platform and sizes it by height above finished ground. The dividing line is 1.2 m. Below it, a deck can cover up to half the yard it sits in, 1.8 m from the rear lot line. Above it, as a deck off a walk-out's main floor often is, it's capped at 30 m² and needs 4.0 m. Stairs aren't part of the platform, but uncovered steps must stop 1.8 m short of the rear lot line. Near the creek valleys, the Town's checklist adds TRCA clearance where it applies.
Checked against the Town of Ajax's own by-laws and pages in November 2026. Rules change, so we confirm them for your address before we draw.
Building Code permit trigger
Under Ontario's Building Code Act, a building includes any structure over 10 m² consisting of a wall, roof and floor or any of them, and no one may construct a building without a permit from the chief building official.
Ontario: Building Code Act, 1992 (2024 Building Code Compendium)Height sets the size
Ajax zoning limits a deck, or platform, by its floor height above finished ground. Less than 1.2 m up, it may cover up to 50% of its yard. More than 1.2 m up, it's capped at 30.0 m² and 50% of the yard.
Ajax Zoning By-law 95-2003, s.4.3 Platforms (PDF)Rear and side setbacks
A deck less than 1.2 m above finished ground must be at least 1.8 m from the rear lot line; one more than 1.2 m up, at least 4.0 m. It must meet your zone's interior side yard setback, which is zero for townhouse decks more than 1.2 m up. Uncovered steps from a deck can come no closer than 1.8 m to the rear lot line or 0.3 m to a side lot line.
Ajax Zoning By-law 95-2003, s.4.2 and s.4.3 (PDF)Stairs aren't counted
Ajax's zoning definition says a platform doesn't include any stairs, so the stair run down to the yard isn't part of the deck's area. Platforms are also left out of lot coverage, which counts the ground floor area of buildings and structures.
Ajax Zoning By-law 95-2003, s.3 Definitions (PDF)Privacy screens on decks
No privacy screens in front yards. In side and rear yards, a screen must be at least 0.6 m from side and rear lot lines and no higher than 2.5 m above grade, and all screens on the lot can total at most 6 m in length.
Ajax Fence By-law 42-2025, s.8 Privacy Screen (PDF)
What the city asks for
The Ajax application.
Issued by: Town of Ajax Building Services, Planning & Development Services (Chief Building Official). We put the package together, submit it and keep you posted.
Documents
- Application for a Permit to Construct or Demolish
- Schedule 1: Designer Information
- Acknowledgement by Applicant of Incomplete Application
- Letter of Authorization
- Applicable Law Checklist, where necessary
- Site plan or legal survey showing the deck's location
- Fully dimensioned construction drawings: materials, pier size and depth, anchorage to the house
- Fully dimensioned foundation plan
- TRCA clearance, if applicable; Durham Region Health approval if next to a septic system
How it goes
- 1We measure the yard and confirm the deck's height band, area and setbacks against Ajax's platform rules for your zone.
- 2We draw the site plan, construction drawings and foundation plan as PDFs, showing pier sizes and depths and the connection to your house.
- 3We submit through the Town's Online Application Portal; after staff pre-screen it, the applicant gets an email with the permit fee and payment instructions.
- 4We answer plan review comments and resubmit until the permit is issued, then print the permit card and a to-scale colour set of approved plans for the site.
- 5Before digging footings, we get Ontario One Call locates, as the Town advises.
- 6We book each inspection listed on your permit card at least 24 hours ahead.
- Processing time
- Not published. The application date is the day after the pre-screen review is approved; once issued, work must start within six months and be completed within one year.
- Inspections
- The Town lists the required inspections on the back of the permit card rather than publishing a deck-specific list. Book at least 24 hours ahead with the permit number, address and inspection code, online or at 905-619-2529 (option 4, then 2), and keep the card posted and one set of approved drawings on site.
Deck drawing — framing plan — Framing plan, section through the deck and elevation. Illustrative sample sheet. Click to enlarge.
Deck drawing — elevations & details
Permit drawings included
We prepare and submit your permit drawings.
A site plan with setbacks, a framing plan, a section through the deck, and footing, guard and stair details, drawn to the Town of Ajax's checklist and submitted with your application.
- Dimensions to your lot lines
- Materials, sizes and spacing
- Footing and base sections
- Code notes for the inspector
Decking · real projects
Recent decking jobs across the GTA.
Real Reformity jobs from our project files. Customer addresses are never published.
Ajax deck permit FAQ
Quick answers.
It depends on its height above finished ground. A deck less than 1.2 m up can cover up to half the yard it sits in and must be 1.8 m from the rear lot line; more than 1.2 m up, it's capped at 30 m² and needs 4.0 m. Stairs don't count as part of the platform, but uncovered steps can't come closer than 1.8 m to the rear lot line.
Ajax accepts drawings by the property owner, a qualified designer, an architect or a professional engineer, depending on the work. A registered designer's drawings must show the firm's and designer's names and BCINs, a statement that they've taken responsibility for the design, and a signature, and Schedule 1 must be completed.
It can. The Town's deck checklist calls for clearance from the Toronto and Region Conservation Authority where it applies, and Durham Region Health Department approval if the deck is connected to or next to a septic system. We check your lot before drawing.
Send the form on this page or call 437-241-6287. We reply within one business day, visit to measure, prepare the drawings for the Town of Ajax, submit the application and give you a fixed written price for the work.
Let us handle the Ajax permit.
We measure, draw it to the Town of Ajax's rules, submit the application and build to the approved plan. One business-day reply.