Markham Deck Builder · Reformity Inc.Deck Builders in Markham
Under Markham's Zoning By-law 2024-19, a deck more than 1.0 m off the ground can extend only 3.7 m from the back wall; in Berczy, Wismer, Angus Glen and other areas under By-law 177-96, it's generally 3.0 m, and lots with a detached garage have their own rules. Any deck over 0.6 m high must also stay 3.0 m from the rear lot line. Decks 1.0 m or lower aren't held to that cap, so with a raised main floor, a two-level design often gives more usable space than one tall deck.
Decking · real projects
Recent decking jobs across the GTA.
Real Reformity jobs from our project files. Customer addresses are never published.
Deck drawing — framing plan — Framing plan, section through the deck and elevation. Click to enlarge.
Deck drawing — elevations & details
Drawn before we build
Drawn before we build in Markham.
Every deck starts with a framing plan, footing layout, and guard and stair details sized for your yard. When your city requires a permit, the drawing set goes in with the application and the inspector checks the build against it.
Decking permits in Markham
Any deck more than 600 mm (24") above grade needs a building permit in Markham, and the City's deck page adds attached decks and decks over 10 m² (108 sq ft); Reformity prepares the permit drawings (site plan, framing plan, footing, stair and guard details), handles the application and confirms with Building Standards whether a low deck needs one.
- Dimensions to your lot lines
- Materials, sizes and spacing
- Footing and base sections
- Code notes for the inspector
Where Ontario's Building Code requires a BCIN-qualified designer or a professional engineer for permit drawings, that sign-off is part of the drawing set.
How our drawings workCity of Markham rules
Decking rules in Markham.
Checked against official municipal and provincial sources. Lots differ, so we confirm the rules for your address at the quote visit.
Private trees
A permit is required for trees 20 cm or more in diameter, measured at 1.37 m (By-law 2023-164).
City of Markham: tree permitsHeritage & conservation
Markham has four heritage conservation districts — Unionville, Markham Village, Thornhill and Buttonville — where most exterior changes, including new fences and driveway changes, need a heritage permit. Valley lands are regulated by TRCA, which can require its own permit.
City of Markham: heritage permitsDeck permits
Any deck more than 600 mm (24") above the ground at any point needs a building permit in Markham. The City's deck page also lists decks attached to the house and decks over 10 m² (108 sq ft), though its general permit list exempts every deck under 600 mm, so we confirm low decks with Building Standards first.
City of Markham: decks & permitsWhat needs a permit
Markham's building permit list includes concrete porches, raised decks, replacing an exterior wall or cladding, and renovating to create a full basement. Maintenance and repairs, fences other than pool enclosures, retaining walls under 1 m, and sidewalks, planters and landscaping need no building permit.
City of Markham: building permitsRaised deck limits
Under Zoning By-law 2024-19, a deck more than 1.0 m above the ground can extend at most 3.7 m from the rear wall, and any deck over 0.6 m high must stay at least 3.0 m from the rear lot line. Under By-law 177-96 the general projection limit is 3.0 m. Lots with a detached garage have separate rules.
Zoning By-law 2024-19 (PDF)Two zoning by-laws
Comprehensive Zoning By-law 2024-19 doesn't cover every Markham lot. Much of the city developed since 1995, including Cornell, Berczy, Wismer, Angus Glen, Box Grove and Cathedraltown, is regulated by By-law 177-96, which has its own deck rules. We check which by-law covers your address before designing.
City of Markham: zoning by-lawsConservation areas
Markham is in the Toronto and Region Conservation Authority (TRCA) jurisdiction. On a lot inside a TRCA Regulated Area, around river or stream valleys and wetlands, decks, pools, sheds and landscaping can need a TRCA permit first, and the City can't issue a building permit until TRCA clears the work.
TRCA: landscaping permits
What we build in Markham
Custom decks for outdoor living.
- Composite
- Pressure-Treated Pine
- Cedar
- Railings & Rails
Neighbourhoods
Decking across Markham.
- Unionville
- Markham Village
- Cornell
- Cathedraltown
- Berczy Village
- Thornhill (Markham)
- Milliken
- Wismer Commons
- Box Grove
- Greensborough
Markham Decking FAQ
Quick answers.
If it's more than 1.0 m above the ground, up to 3.7 m from the rear wall under Zoning By-law 2024-19, or generally 3.0 m in areas under By-law 177-96 such as Berczy, Wismer and Angus Glen. Either way, any deck over 0.6 m high must stay at least 3.0 m from the rear lot line. Lots with a detached garage have separate rules, so we check yours first.
Any deck more than 600 mm (24") above the ground at any point needs a building permit in Markham. The City's deck page also lists decks attached to the house and decks over 10 m² (108 sq ft), though its general permit list exempts every deck under 600 mm, so we confirm low decks with Building Standards first.
A permit is required for trees 20 cm or more in diameter, measured at 1.37 m (By-law 2023-164).
Send the form on this page or call 437-241-6287. We reply within one business day, visit your Markham property to measure and check the City of Markham rules for your lot, and give you a fixed written price.
Free on-site quote
Planning decking in Markham?
We'll measure, check the City of Markham rules for your lot, draw it up and give you a fixed written price. One business-day reply.