Deck Permits & Ontario Building Code: A Norfolk & Oxford County Homeowner's Guide

Do you need a permit to build a deck in Ontario? Short answer: usually yes. Under the Ontario Building Code (OBC), a building permit is required for any deck that is **more than 24 inches (about 600 mm) above grade at any point**, or any deck attached to the house — regardless of height. Detached, ground-level platforms under 10 m² (108 sq ft) and under 24" off grade are typically exempt, but Norfolk County and Oxford County still expect you to confirm setback and zoning compliance before you build.

If you're unsure, call your municipal building department before the first post hole goes in. A retroactive permit costs more than a regular one, and an inspector who finds an unpermitted deck during a future sale can force you to tear it down.

What the Ontario Building Code requires for residential decks The OBC (Part 9 for houses) sets minimums for every structural element of a deck. These are the ones we get asked about most:

Footings and frost depth Footings must reach below the local frost line. In Norfolk and Oxford County, that's **1.2 m (4 ft) minimum** for sonotube or helical piles. Surface blocks and "floating" deck pads do not meet code for any deck requiring a permit.

Guards (railings) - Required on any walking surface more than **600 mm (24")** above adjacent grade. - Minimum height: **900 mm (36")** when the deck surface is less than 1.8 m above grade; **1070 mm (42")** when higher. - Openings: no gap may allow a **100 mm (4")** sphere to pass through (the "4-inch sphere rule"). - Guards must resist a horizontal load of **0.5 kN (about 113 lb)** at the top rail.

Stairs - Maximum rise: **200 mm (7.87")**. Minimum run: **255 mm (10")**. - Handrails on stairs with more than 3 risers. - Stair landings sized at least as wide as the stair.

Ledger attachment If your deck attaches to the house, the ledger must be lag-bolted or through-bolted into the rim joist with proper flashing — never nailed, never attached to siding. Joist tape over the ledger and joists is best practice in our climate.

Norfolk County deck permit basics Norfolk County's Building Division processes deck permit applications through their online portal. You'll need:

• A site plan showing setbacks from property lines (typically **1.2 m / 4 ft** minimum for rear and side yards in residential zones).
• A construction drawing showing footing size and depth, joist size and span, beam size, post size, guard height, and stair details.
• The permit fee (currently scaled by deck size).

Turnaround in Norfolk is typically 10 business days, but stretches to 6–8 weeks once spring hits. Submit by mid-March if you want a May build.

Oxford County deck permit basics In Oxford County, permits are handled by the **lower-tier municipality** (Woodstock, Tillsonburg, Ingersoll, Norwich, etc.), not the County. Requirements mirror the OBC, but setback minimums and review timelines vary slightly by township. Tillsonburg, for example, requires that your application include the OBC schedule for the designer.

We pull permits as part of every deck contract — homeowners shouldn't be doing this themselves.

Common mistakes that fail inspection After 10 years of building decks across both counties, these are the failures we see most often on DIY and unpermitted decks:

• Footings too shallow (above frost line) → heaving after one winter.
• Joist hangers nailed instead of using structural screws or proper hanger nails.
• Guards under 36" or with gaps wider than 4".
• Ledger nailed (not bolted) to the rim joist.
• Stairs without a proper landing at the bottom.

Getting started the right way If you're planning a deck in Norfolk County or Oxford County, the cheapest path is the permitted path. We handle the drawings, permit submission, inspections, and final sign-off as part of every build — so the deck you get is the deck the inspector signs off on.

Call 226-239-0239 or request a free on-site estimate, and we'll walk your yard and explain exactly what your project needs to meet code.