Permits 101 · 6 min read · Last updated
Every permit conversation with a property owner starts with the same five questions. Here they are, answered plainly for Ontario — with links to our deeper guides where the details matter.
1. “Do I actually need a permit for this project?”
This is always the starting point. Many owners assume permits are only for massive structural builds, but the threshold is much lower than they expect.
The reality: a permit is typically required for any work that affects safety, structure, or your zoning footprint. Common triggers:
- Any structural change — like cutting through a load-bearing wall for an open-concept kitchen, or cutting a new entrance into the foundation.
- New accessory structures — a shed, detached garage or deck beyond the small-structure exemption (in Ontario, generally 10 m² / about 108 sq ft, with conditions).
- Adding or altering plumbing or HVAC systems. (Electrical work runs through its own stream in Ontario — the Electrical Safety Authority — rather than the building department.)
- Creating a secondary dwelling unit — a basement apartment or garden suite.
2. “How much is this going to cost?”
The reality: there is no flat rate — every municipality sets its own fees, typically based on the floor area of the work, a rate per project type, or (in some municipalities) a percentage of construction value, with a minimum fee for small jobs. Our Toronto fee guide walks through the math.
The “hidden” costs surprise owners more than the fee itself: the architectural, structural or site drawings needed to apply usually cost more than the permit — and if the design violates a zoning by-law, a minor variance through the Committee of Adjustment adds its own fees and months of schedule.
3. “How long will it take to get approved?”
The reality: simple residential permits (a deck, an interior renovation) are legally reviewed within 10 business days in Ontario, and other small buildings within 15 — but only once the application is complete. Projects needing zoning relief can stretch to several months.
The #1 bottleneck: the clock only starts when the municipality deems your application complete. Submit incomplete drawings and the package comes back — resetting the wait. Full breakdown in our timeline guide.
4. “What exact drawings and paperwork do I need?”
The reality: a standard residential package is a mix of municipal forms and technical drawings:
- Site plan — property lines, existing structures, and setbacks to the proposed work.
- Floor plans — layout, room uses, structural spans.
- Elevations & cross-sections — heights, wall assemblies, insulation values, foundation depth.
- Schedules & forms — proof of ownership, designer qualification (BCIN) forms, and energy-efficiency compliance where applicable.
Requirements scale with the project — the document table in our deck permit guide shows the minimum end of the spectrum.
5. “What happens if I just do the work without a permit?”
The reality: asking forgiveness instead of permission carries real teeth. If unpermitted work is discovered — often via a neighbour's complaint or a passing inspector — the municipality can:
- Issue a stop-work order, halting the project immediately.
- Levy fines and surcharges that far exceed the original permit fee.
- Require you to uncover finished walls for inspection — or demolish work that can't meet code or zoning.
- Leave lasting insurance and resale problems: unpermitted work can jeopardize claims and routinely derails sales when buyers request permit history.
Quick tip for owners: the property owner is legally responsible for ensuring a permit is in place — even when a contractor promises to “handle everything.” Always ask to see the approved, stamped permit drawings before any tools hit the site.
Want the professional-grade version of this list? See the five questions permit consultants ask building departments — the ones that surface problems before they stall a project.
Skip the paperwork
Describe your project in plain English and Permits2Go finds, fills and assembles the exact municipal forms you need — for Toronto, Mississauga and municipalities across Ontario.
This guide is general information, not legal or professional advice. Permit requirements, by-laws and fees change and vary by municipality — always confirm the current rules with your local building department before you design or build.