A homeowner in Alta Vista called us last fall after her kitchen renovation, run by a different contractor, came in far over the original quote. The final invoice was roughly half again the number she signed. She wanted to know if it was normal.
It is normal in the bad sense. About 60% of renovations in Ottawa run over budget, usually by 18% to 35%. It is also entirely avoidable on the contractor side, and 80% predictable on the homeowner side. After 20 years quoting Ottawa renovations, here are the five reasons projects blow up, in order of frequency.
1. The quote was incomplete from day one
What it drivesd">What it drivesd">What it drivesd">What it drivesd">What it drives: the largest single category of overrun on both kitchens and bathrooms.
The single biggest source of "going over budget" is a quote that was never complete. The contractor wrote a number to win the job and left out items they knew would be needed.
The classic incomplete quote excludes: electrical permit fees, dump fees, demolition disposal, paint, baseboards, the second coat of finish flooring, GFCI outlets, garbage cans for the trades, plumbing rough-in beyond the existing fixtures. Each of those is a line item that was simply never counted. Stack five of them and the "extras" add up before any change order has even happened.
The fix is reading the quote. A real quote names every line item. If a quote is one page and reads "Kitchen renovation, including labour and materials" with a single lump-sum number, it is not a quote, it is a marketing document. A real fixed-price quote runs 6 to 12 pages and lists everything from cabinetry to the brand of caulk.
Our project estimating process is built around making the quote so detailed there is nothing left to "discover" later. It takes about 3 weeks to write a complete quote on a major project. The contractors who turn around a quote in 3 days are the contractors whose final invoices come in 30% over.
2. Surprises behind the walls
What it drives: a wide swing depending entirely on what demolition uncovers.
Ottawa has a lot of housing stock built between 1940 and 1985. That stock has aluminum wiring, knob-and-tube wiring, asbestos vermiculite insulation, lead paint, undersized supply plumbing, and joist spans that violate current OBC §9.23.
None of those problems are visible during the quote walk-through. The contractor sees finished drywall and a kitchen that "just needs a refresh." The framing inspection happens on demolition day, which is week 2. Suddenly there is a mid-project conversation about the electrical work needed to bring the panel and wiring to current code.
The fix is two-part. First, hire a contractor who builds a contingency line into the quote. We allocate 8 to 12% of project value to "concealed conditions" on any home built before 1990, which absorbs most surprises without the homeowner getting a phone call. Second, have a written change-order process so any concealed condition that exceeds contingency triggers a clear pause-and-decide moment, not a surprise on the invoice.
3. Scope creep from the homeowner side
What it drives: the most common overrun on otherwise well-quoted projects.
The kitchen renovation that grows by a third because halfway through the homeowner decided to also redo the powder room "while the trades were here." This is the most common cause of overrun on well-quoted projects.
It is not a contractor fault. It is a process fault. The homeowner assumed adding the powder room mid-stream would be cheap because the floor tiles were already on order. Reality, the powder room added real cost because the plumber had to come back, the electrician had to add a circuit, the drywall finisher needed two extra days, and the project schedule extended by 3 weeks.
The fix is a written scope-change process. Every addition gets a separate fixed-price change order, signed before work begins. No verbal "while you are here" requests. The homeowner sees the real number for the addition before agreeing, not after the work is done.
4. Buying decorative materials at random instead of by spec
What it drives: overruns that scale with every selection made above the allowance.
The renovation budget sets a tile allowance. The homeowner falls in love with a showroom tile that costs several times that allowance. Multiplied across 240 square feet of kitchen and bathroom tile, the overage is significant, before installation labour gets affected.
Tile allowances are the most common, but the same pattern hits faucets, light fixtures, hardware, and flooring. The homeowner sees the design and wants what they want. The contractor's allowance was based on category-typical pricing, not the homeowner's eye.
Allowances are guesses. Selections are facts.
The right way to bid a renovation is to skip allowances entirely and have the homeowner make every selection before the quote is finalized. We require all major selections (cabinetry, counters, tile, faucets, fixtures, lighting) to be locked in before we issue a fixed-price quote. It takes longer up front. It eliminates 90% of "I went over allowance" overruns. The kitchen quote that comes back in 5 days leaning on open allowances has built-in slippage. The kitchen quote that takes 4 weeks with no allowances is a quote that closes at the number.
5. The contractor priced low to win the job
What it drives: the largest overruns of all, and the worst on bigger projects.
Some contractors price below market specifically to win, knowing the project will run over and that the homeowner will pay rather than fire them mid-renovation with a half-built kitchen. The "lowball, then upsell" strategy is dishonest, and it works because homeowners shop on price.
The signs to watch for in any quote:
- The number is 20% or more below the next-lowest competitor on the same scope
- The quote is one page or under three pages with vague descriptions
- The contractor refuses to name brand and model numbers for fixtures, hardware, and counters
- "Allowances" are vague or set unrealistically low for the finishes you actually want
- The deposit structure is front-loaded (50%+ before any work starts)
If three of those signs are present, the quote is a marketing exercise, not a real number. Walk away.
The honest contractor's quote will look more expensive on paper. The honest contractor's invoice at the end of the project will be the same as the quote. The lowball quote always ends up being the most expensive renovation.
What a fixed-price quote looks like in practice
Here is the structure that prevents overruns. We write every quote this way.
- Scope of work: every room, every wall, every plumbing fixture, every electrical change. 1 to 3 pages.
- Materials specification: every cabinetry brand and model, every counter material and finish, every faucet, every light fixture, every tile, every hardware piece, by brand and model number. 2 to 5 pages.
- Permit and engineering line items: City of Ottawa permit fees (minimum $117), BCIN drawings, structural engineering if required, the architectural plan stamp.
- Demolition and disposal: dump fees, hazardous materials handling if applicable.
- Concealed conditions allowance: 8 to 12% of project value, named explicitly so the homeowner knows what it covers and what triggers it.
- Schedule: start date, finish date, key milestones with dates.
- Payment schedule: deposit, milestone payments, holdback (10% on completion).
- Warranty: 1-year DTR workmanship, 25-year manufacturer where applicable, 10-year structural where applicable.
The bottom-line lesson
Renovations do not blow the budget by accident. They blow the budget for predictable reasons that can be designed out of the project before work begins. A fixed-price quote with no allowances and a real concealed-conditions contingency closes at the quoted number 95% of the time. A back-of-envelope quote with vague allowances and no contingency runs 25 to 40% over, every single time.
If you are about to sign a renovation contract, the question is not whether the contractor's number is the lowest. The question is whether the contractor's number is the final number. Those are different things.