Permits are one of the most misunderstood parts of renovating, and getting them wrong can cost you far more than the permit itself. Here's a plain-language overview of when you generally need one in Ontario, though your municipality is always the final authority.
As a general rule, work that affects the structure, safety, or major systems of your home requires a permit. That includes removing or altering load-bearing walls, building an addition, finishing a basement with new bedrooms, adding or relocating plumbing, and many electrical changes. Decks above a certain height and secondary suites also typically require permits.
Purely cosmetic work usually does not require a permit: painting, flooring, replacing cabinets in the same layout, or swapping fixtures like-for-like. The grey area is wide, though, which is why a quick check with your municipality or contractor before starting is always worth it.
Skipping a required permit can seem faster and cheaper, but it creates real risk. Unpermitted work can stall a future home sale, void insurance claims, and force expensive retroactive fixes if it doesn't meet code. Buyers and their lawyers increasingly ask for proof that renovations were permitted.
A reputable contractor treats permits as part of the job, not an obstacle, and will handle the application and inspections for you. If you're unsure whether your project needs one, that's exactly the kind of question we answer up front, before any work begins.