Change orders are where Ottawa renovation budgets quietly go to die. Most homeowners end up 15-30% over their original contract on change orders alone, and a large share of that is avoidable. The problem is structural: once construction starts, you cannot easily switch contractors, and that leverage shift is exactly when change-order pricing gets aggressive. This 2026 guide explains what a legitimate change order looks like, why they get systematically inflated, the discoveries that trigger them most often in Ottawa's older housing stock, and — most importantly — the contract clauses and budge...
A proper change order is a clean, documented amendment to your contract — not a verbal 'oh, that'll be extra.' It includes a written description of the changed scope, a cost breakdown (labour hours, materials, subcontractor charges, and markup shown separately), and the schedule impact stated in calendar days. It is signed by both parties before the work begins, numbered sequentially (CO-001, CO-002), and attached to the original contract. Reputable Ottawa contractors produce this paperwork even...
At minimum: a unique number, the date, a plain-language description of what is changing and why, an itemized cost (not a lump sum), the markup percentage applied, the revised contract total, the number of days added to the schedule, and signature lines for both parties. Anything less is not a change...
Every change order has a schedule cost as well as a dollar cost, and Ottawa's seasonality magnifies it. A change discovered during framing can ripple through every downstream trade — plumbing, electrical, drywall — pushing inspections and finish work back by days or weeks. If those delays push exter...
The economics are simple and not in your favour. Once your kitchen is gutted or your basement is framed, switching contractors is painful and expensive, and contractors know it. There is no competitive bid for a mid-project change, so margin expansion is easy: change orders routinely carry 25-40% markup versus the 15-25% on the base contract. Some contractors even bid the original job thin, expecting to recover margin on changes. The defence is to remove the incentive in advance by capping chang...
Most change orders fall into predictable categories, and several are amplified by Ottawa's housing stock. Discoveries top the list: knob-and-tube wiring, galvanized or lead plumbing, asbestos, mould, and hidden water damage are common in the city's many 1950s-1970s homes and in century homes in neighbourhoods like the Glebe, Sandy Hill, and Old Ottawa South. Homeowner additions are next — after seeing the rough-in, owners often decide to add an outlet, move a wall, or upgrade a finish. Permit-dr...
If you are renovating a pre-1980 Ottawa home, expect 10-25% in legitimate discovery-driven change orders and budget for it. Hidden conditions behind plaster and under subfloors simply cannot be priced until walls are open. A contractor who quotes a century home as if it were new construction is eith...
City of Ottawa inspectors can require work you did not anticipate. A framing inspection may flag undersized joists; an electrical inspection by the ESA may require additional circuits or smoke-alarm interconnection; an insulation inspection may demand compliance with OBC 9.36 energy provisions. Thes...
Your contract is the only place you have real leverage over change orders, so use it. Require: (1) change-order markup capped at the base-contract rate; (2) all change orders written and signed before work begins, with no verbal or implied changes binding; (3) material substitutions only with your written approval, never at the contractor's sole discretion; (4) a discovery contingency reserve for older homes that the contractor draws against with documentation rather than at full markup; (5) an ...
Treat a change-order contingency as a discovery reserve, not a slush fund. Industry-standard contingencies in Ottawa: 10-15% for cosmetic work, 15-20% for mid-range renovations, 20-30% for a full gut on an older home, and 30-40% for a heritage gut where surprises are guaranteed. Hold this reserve separately and require documentation for every draw against it. Crucially, do not reveal your contingency to the contractor — if they know it exists, it has a way of getting spent. A well-budgeted proje...
For perspective on 2026 Ottawa pricing, moving a single electrical outlet or adding a circuit runs roughly $200-$650; relocating a load-bearing wall with a new beam $4,000-$12,000; asbestos abatement of a small area $1,500-$4,000; replacing a section of galvanized supply plumbing $1,800-$5,500; and ...
When a change order lands, slow down before signing. Verify the described work genuinely falls outside your original scope — if it was already in Schedule A, it is not a change order. Check that labour, materials, and markup are itemized and that the markup matches your contracted cap. Confirm the schedule impact is reasonable. For discovery items, ask for a photo of the condition (the open wall, the failed pipe) so you are paying for a real problem, not a manufactured one. If the cost seems hig...
Maintain a simple log: number, date, description, cost, days added, running contract total, and approval status. Update it every time a change order is issued so you always know your true committed total, not the original contract figure. Homeowners who skip this wake up at the end of the project sh...
Base-contract markup is typically 15-25%. Change orders often carry 25-40% markup unless you have capped change-order markup at the base-contract rate in your original contract. Always negotiate that cap — it is the single highest-value clause for controlling overruns. Get the markup percentage stated explicitly in the contract so there is no ambiguity once construction is underway and your leverage has shifted to the contractor.
No. Contractors cannot proceed with changed work without your written approval. If you decline, work continues per the original scope or you negotiate an alternative. Be careful, though: declining a legitimate code-required change can leave you with a non-compliant build that fails inspection.
Ottawa has a large stock of 1950s-1970s and century homes where discovery — knob-and-tube, asbestos, galvanized plumbing, hidden water damage — is common. Expect 10-25% in legitimate change orders on older homes. Anything well beyond that usually signals a lowballed original scope.
They should not without your written approval. If you are billed for verbal-change work, dispute the invoice in writing, citing your contract's change-order procedure. Verbal approvals are generally unenforceable, which is exactly why every change should be written and signed before work begins.
Use a contingency reserve: 10-15% for cosmetic work, 15-20% for mid-range, 20-30% for a full gut on an older home, and 30-40% for a heritage gut. Treat it as a documented discovery reserve, not a slush fund, and request paperwork for every draw.