Why do two Barrhaven deck quotes for the same size differ so much?

When two quotes for the same size differ a lot, start with what each builder actually included in the price.

Published Ottawa and Ontario builder prices run about $25 to $65 per square foot for pressure-treated wood, $45 to $80 for cedar, $45 to $95 for composite, and $59 to $110 or more for PVC, all labelled as published Ottawa and Ontario builder prices read in September 2026. Two quotes can also diverge when one builder has priced a complete job and the other only the boards and framing.

Here is what quotes often differ on, without any of these being more important than the others: the board material chosen, the foundation type (concrete piers versus helical piles), the height of the deck above grade and how many levels it has, the stair configuration and number of risers, the railing type and infill design, removal and disposal of an existing deck (the City of Ottawa says wood from demolition is not collected with regular garbage and goes to the Trail Road Landfill Site or another landfill), permit drawings (about $399 to $2,500 per set on the published prices of three drafting and design firms), the City building permit fee itself, and who applies for the permit and books the three required inspections (excavation or foundations, framing, and final). Some published packages exclude railings and steps entirely, so a lower headline number may simply be a shorter scope.

The permit question matters here. Under the City of Ottawa's rules, a deck attached to the house with a walking surface more than 600 mm (24 in.) above adjacent grade requires a building permit, as does an elevated deck providing principal access to the building. The City's first review takes 5 business days. The permit fee is $12.75 per $1,000 of assessed valuation of the work, with a minimum of $117. As an illustration of the formula: a $15,000 deck works out to $191.25. Where the decking material is other than conventional lumber, the permit application also needs a material testing report (CCMC or BMEC). Both Zoning By-laws 2008-250 and 2026-50 apply to applications deemed complete on or after March 11, 2026, with the most restrictive provisions from each governing setbacks and projections: confirm the rules for your specific lot with the City.

Soil conditions vary by lot, and where a builder or engineer finds peat, filled ground or sensitive clay including Leda clay, the 2024 Ontario Building Code requires an engineered foundation design rather than the standard prescriptive approach. One quote may assume straightforward soil; another may have already priced for something more involved.

To make the two quotes comparable, ask each builder to give you a written, itemised scope that lists the board material and grade, the foundation type and depth, the guard height and infill design, stair count, what happens to the old deck if there is one, and whether drawings and permit applications are included. Once the scopes match, the price difference tells you something real.

Before you sign, ask each builder to walk you through exactly what triggers a change order on their quote and what is not covered.