How much should I budget for unexpected costs during a renovation in NB?

Budget a contingency of 15–20% of your total renovation cost for standard projects, and 20–25% for gut renovations of older NB homes — these aren't arbitrary cushions, they reflect the reality of what NB renovators routinely find once walls open and floors come up.

The contingency percentage scales with risk. A cosmetic renovation on a recently built home — new paint, flooring, and fixture updates — has relatively low hidden-issue risk, so 10–15% is reasonable. A mid-range kitchen or bathroom renovation that opens walls, touches plumbing or electrical, and involves some demolition warrants 15–20%. A full gut renovation of a pre-1980 NB home where you're taking the house down to studs should have 20–25% set aside, because you are virtually certain to find something that adds cost. In dollar terms, if your primary budget is $60,000, carry $9,000–$15,000 in contingency before you start.

What actually burns through contingency funds in NB homes? Knob-and-tube wiring is one of the most common discoveries — it's present in a surprising number of homes built before 1950, and once it's discovered, your electrician and insurer may require full replacement before the project can proceed. Asbestos-containing materials in vinyl floor tiles, pipe insulation, ceiling texture, and some drywall compounds are common in homes built before 1990. Professional abatement — the legally required approach — typically runs $3,000–$15,000 depending on quantity and material type. Subfloor rot beneath old bathrooms or around kitchen sinks is extremely common in NB given the province's humidity history and older plumbing systems. Replacing a section of rotted subfloor and framing adds $1,500–$5,000 depending on extent. Mould remediation in basements and behind exterior walls — particularly in homes near the Bay of Fundy or Saint John River valley where moisture infiltration is prevalent — can run $2,000–$10,000 before any renovation work begins.

Structural discoveries are another contingency consumer. A wall that was assumed to be non-load-bearing turns out to carry a beam. A header over a window opening was undersized by original construction standards. Joist ends are rotted at the foundation sill. Each of these requires an engineer's assessment (typically $500–$1,500 per site visit) plus the cost of the structural correction.

The practical way to manage contingency is to keep it in a separate account from your renovation payments. Don't treat it as money to spend — treat it as insurance. If your renovation closes out cleanly and only 5% of the contingency gets used, that's a good outcome. Don't spend the remainder until you have a Certificate of Substantial Completion or the equivalent sign-off from your contractor and any inspectors.

One more NB-specific factor: supply chain delays and material price fluctuations have been significant in recent years, and NB is at the end of most supply chains. A quoted price for windows, cabinetry, or specialty materials may be based on current pricing that changes between signing and procurement. Locking in material pricing in your contract where possible, or building a buffer for price escalation on long-lead items, is smart risk management for NB projects.

Any contractor who tells you that your project is straightforward and no contingency is needed has either never renovated an NB home before or is telling you what you want to hear. The province's housing stock and Maritime climate make surprises the rule, not the exception. Get connected with experienced local renovation professionals through New Brunswick Renovations — they know what to look for before work starts, which keeps surprises manageable.

---

Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• Thirty Four Renovations
• Gionetterenovations