Top 7 Home Renovations That Always Need a Permit in Ontario
- Permit Works
- Jul 27
- 4 min read
Buying supplies on Saturday only to have the city issue a stop-work order on Monday is every DIYer’s nightmare in Toronto and across Ontario. The fix is simple: check whether you need a home renovation permit in Ontario before you swing the first hammer. Below are seven projects—some obvious, some “grey areas” like egress windows—that always trigger a permit under the Ontario Building Code and most municipal bylaws. Skip them and you risk costly delays, fines, insurance voids, and even a forced tear-down.
Table of Contents
Removing Structural Walls
When a Home Renovation Permit in Ontario Is Non-Negotiable
Knocking down a wall to open up that century-home kitchen? If the wall bears any structural load, you must apply for a building permit—and usually provide an engineer’s stamped drawing—before a single stud is cut. Removing load-bearing walls without approval violates the Building Code Act and can invalidate your home insurance.
How to Tell If It’s Load-Bearing
Check whether the wall runs perpendicular to the floor joists
Look for beams or posts directly below in the basement
Review original plans or hire a structural engineer
Enlarging or Adding Egress Windows
Adding a legal bedroom in the basement? The Ontario Code requires an egress window that opens at least 0.35 m², with no dimension under 380 mm, and a clear space of 550 mm in front. Any enlargement of an opening or cut into a foundation wall is a material alteration—automatic permit territory.
Common Missteps
Ordering a slider that meets the area but fails the minimum height
Forgetting that window wells must allow full sash swing
Ignoring distance to property line (fire-spread rules)
Finishing or Remodeling a Basement
If your basement makeover adds a bedroom, alters the structure, waterproofs, or installs new plumbing/HVAC, a permit is mandatory. Cosmetic jobs (paint, flooring) may be exempt, but once you frame new walls or touch drains, file the application.
Permit Checklist for Basements
Structural changes (underpinning, new stairs)
New insulation under Part 9 energy upgrades
Second-suite creation triggers fire-separation and egress rules
Building Decks & Porches Above Thresholds
Across Ontario, a deck higher than 600 mm (24 in.) off grade or larger than 10 m² needs a building permit. The City of Toronto lists height alone (> 60 cm) as sufficient. Guard‐rail, footing, and setback rules also apply.
Grey Areas
Floating decks often exceed 10 m² even if under 600 mm
Porch roofs convert the structure to an “addition,” escalating the review
Hot-tub platforms require structural snow-load checks
Creating a Secondary Suite
Whether you call it a basement apartment, nanny suite, or garden suite, adding a second dwelling unit always needs a permit. Expect reviews for fire separations, sound transmission, parking, and plumbing capacity. Most municipalities now fast-track compliant designs, but only if plans are submitted first.
Code Essentials
Minimum ceiling height (generally 1.95 m finished)
Independent HVAC or in-suite smoke alarms interconnected
Separate egress path (window or exterior door)
Moving or Adding Plumbing Lines
Relocating a kitchen island sink or adding a basement bathroom involves new plumbing. The Building Code classifies this as a “material alteration,” so a permit is compulsory—even if the rest of the space is untouched. Pair this with an ESA electrical notification for any wiring.
Typical Triggers
Cutting concrete slab to reposition floor drain
Adding a backwater valve or sump pump tied to the storm sewer
Rough-ins for future wet bars or laundry centres
Altering Roof Structure or Dormers
Installing skylights that remove more than one rafter, adding dormers, or replacing traditional framing with engineered trusses changes structural loads—thus requires a permit. The optics are upward, but the paperwork is on the ground.
Permit-Sensitive Roof Works
Cutting rafters for a Velux skylight wider than one bay
Building shed dormers for attic conversions
Re-pitching roofs for solar panel clearance
Key Takeaways
Ontario’s Building Code + municipal bylaws decide when a permit is mandatory
Structural, life-safety, or plumbing changes = permits every time
Fines, insurance issues, and resale delays await DIYers who skip permits
A professional code review saves weeks and thousands in rework
Permit Works handles drawings, engineering, and submissions city-wide
FAQ Section
How long does it take to get a home renovation permit in Ontario?
Simple interior alterations can be approved in 10 business days, while structural or second-suite applications may take 3–6 weeks depending on municipal workload.
Can I submit drawings I made myself?
Yes—if they meet scale, detail, and Building Code standards. However, most cities require structural components to be stamped by a licensed engineer.
What happens if I start work without a permit?
Inspectors can issue a stop-work order, levy fines, and force you to open finished walls for inspection or even remove unauthorized work.
Is an ESA electrical permit the same as a building permit?
No. Electrical Safety Authority permits cover wiring only. Structural, plumbing, and life-safety items are governed by municipal building permits.
Do rural Ontario townships have different rules?
They still follow the Ontario Building Code, but zoning setbacks and fee schedules vary. Always confirm with your local building department.
Ready to Secure Your Permit?
From structural engineering to full submission packages, Permit Works streamlines the approval process across the GTA. Call 416-989-8900 today for a free 15-minute consultation and start your renovation on solid legal ground.
About Permit Works
Permit Works is a Toronto-based consulting firm that helps homeowners and contractors navigate Ontario’s building-permit process—fast, friendly, and 100 % code-compliant.