What renovating does to your home insurance, and how not to find out the hard way

Rule 1: tell your insurer, in writing, early

Home policies operate on the principle that a material change in risk must be reported. A renovation, an addition, or trades working in your house is exactly that. Industry guidance from the Insurance Bureau of Canada describes notifying the insurer around the start of significant work; the safe practice is simpler: written notice to your broker before the project starts, with the scope described. It costs nothing, and its absence is the first thing an adjuster looks for after a loss.

Rule 2: the vacancy trap

Moving out during a major renovation can be the most expensive convenience you ever buy. Ontario policies commonly treat a home left vacant beyond roughly 30 days as a suspended risk for key perils such as water damage and vandalism unless a vacancy permit is arranged. If your project has you living elsewhere, that one phone call to the broker is the difference between covered and abandoned. Check your own policy's exact wording; the 30-day figure varies by insurer.

"Every winter I hear a version of the same story: family moves out for the big reno, a fitting lets go in week five, and the claim dies on a vacancy clause nobody had read. The fix costs one phone call before demolition. I put it on my pre-construction checklist the way I put the permit on it."

Mitch Fraser, owner, Ontario Contracting Co.

Rule 3: know who insures the build itself

Your homeowner policy covers the house; it is not designed to cover a major construction project in progress. Larger jobs are commonly written under a builder's risk (course of construction) policy covering the work, materials on site, and the structure during construction. Ask two questions before any big project: does my policy need an endorsement, and whose builder's risk covers the build? Then pair it with the contractor-side checks that are always in season: the $2 million liability certificate and WSIB clearance in our verification walkthrough, because an uninsured contractor's mistake becomes your claim.

Rule 4: sudden beats gradual, every time

Water and mould claims turn on one distinction: policies generally respond to sudden and accidental events (the burst pipe) and exclude gradual ones (the slow leak, chronic seepage, long-term condensation). Mould coverage typically exists only downstream of a covered sudden event, often with sub-limits. The renovation-world translation: the wet-basement problem you have been living with is not an insurance project, it is a construction project, and pretending otherwise wastes a season. What the actual fixes look like is on our waterproofing page, and what mould findings mean mid-renovation is in the mould guide.

The renovation insurance checklist

1. Written notice to your broker before work starts, scope described
2. Vacancy permit if you are moving out during the work
3. Builder's risk conversation on major projects; endorsement question on modest ones
4. Contractor's liability certificate and WSIB clearance verified and on file
5. After completion: updated replacement value, since the renovated house is worth more than the one your policy priced