Rebuilding an old deck bigger in Kanata: new zoning check?

A bigger new deck is measured against today's rules for its size, height and position, which in Ottawa now means both Zoning By-law 2008-250 and Zoning By-law 2026-50 apply simultaneously, with the more restrictive provision from each winning out.

What triggers a permit for the new deck

The City of Ottawa's permit rules are straightforward. If the new deck is attached to the house and its walking surface will be more than 600 mm (24 in.) above the adjacent grade, a permit is required regardless of size. If it is an elevated deck providing principal access to the house, a permit is required. A freestanding deck needs a permit only when it is both greater than 10 square metres (approximately 108 square feet) in area and more than 600 mm above grade.

Ottawa enacted Zoning By-law 2026-50 on March 11, 2026. Building permit applications deemed complete on or after that date must comply with both by-laws, with the most restrictive provisions applying. For a deck, the key questions are setbacks from rear and interior side lot lines, how much of the yard the deck can occupy, and whether any part of the deck projects into a required yard.

Under Zoning By-law 2026-50 section 204, an uncovered, unenclosed deck with a walking surface not higher than 0.6 metres above the adjacent ground has no minimum setback in the rear or interior side yard. In all other cases, the minimum setback is 1 metre from any lot line and the maximum projection into a yard is 2 metres. The deck may also have a maximum of two enclosed sides. Because both by-laws apply and the more restrictive provision governs, you cannot rely on one by-law alone to confirm what is allowed on your specific lot. A designer or the City can run that check for you.

Going bigger also raises the question of soft landscaping. Zoning By-law 2026-50 defines a deck as hard landscaping, so if your zone sets a minimum soft-landscaped area, the new deck area does not count toward it. We did not research the specific minimums for your lot's zone, so confirm that with the City.

The City requires scaled, fully dimensioned drawings: a site plan showing the deck dimensioned to the house, property lines and any septic system; a foundation and framing plan covering footing type, size and location, joists, beams, posts, decking and the deck-to-house connection; and elevations showing the walking surface height above grade, stair rise and run, and guard information. If the decking material is anything other than conventional lumber, a CCMC or BMEC material testing report is also required. The City's first review target is 5 business days. The permit fee is $12.75 per $1,000 of assessed value of all materials, labour and professional fees, with a minimum of $117.

Before anyone digs new footings, a locate must be requested through Ontario One Call at least 5 business days before digging starts. That applies whether the builder digs or you do.

A designer who knows both by-laws is the right first call here, because the setback and soft-landscaping questions depend on your specific lot dimensions and zoning subzone, and getting those wrong before drawings are submitted costs time.