1. Do You Actually Need a Permit? (The Threshold Most Owners Get Wrong)
Under the Building Code Act, 1992, you need a building permit before constructing any new structure larger than 10 square metres (108 square feet), adding to an existing building, altering plumbing or HVAC systems, installing a pool deeper than 36 inches, building a retaining wall taller than 1 metre, or finishing a basement that introduces bedrooms or secondary suites.
“Your home insurance may deny coverage for damage from unpermitted structural work. The permit fee is the cheapest insurance you'll ever buy.”
2. The 2024 Ontario Building Code — What Changed for Permit Applications
As of January 1, 2025, the 2024 Ontario Building Code became the in-force code for all new permit applications. Since April 1, 2025, every application must comply with the 2024 edition — older drawing sets prepared under the previous code will be rejected unless they were submitted during the transition window (which ended March 31, 2025).
- Radon rough-in: All new homes must include a sub-floor depressurization rough-in to manage soil gas.
- Energy efficiency (SB-12): Stricter insulation RSI-values for walls, roofs, and foundations, plus tighter U-values for windows.
- Carbon monoxide alarms: As of January 1, 2026, CO alarms required on every floor with fuel-burning appliances or attached garages.
- Secondary suites: New smoke-tight gypsum board barrier requirements and minimum ceiling height of 1.95 metres.
- Development charges: Non-rental residential DCs are now payable at occupancy, not at permit issuance — changing project cash flow planning.
3. What Goes Into a Complete Permit Application
Incomplete applications are the single biggest cause of delays. A complete package includes:
Application form
Provincial Permit to Construct or Demolish (updated for 2024 OBC)
Site plan
Property boundaries, proposed footprint, setbacks from all lot lines, and grades
Architectural drawings
Floor plans, elevations, sections — dimensioned and code-referenced at scale
Structural drawings
Foundation plans, framing plans, beam/column schedules — P.Eng.-stamped
Schedule 1 & 2
Designer acknowledgement forms confirming qualified preparation
Applicable Law checklist
Confirming zoning, conservation, heritage approvals
Energy compliance
SB-12 documentation demonstrating code-minimum performance
Additional docs
Tarion declaration (new homes), septic/CA approvals (rural sites)
4. How Much Do Building Permits Cost in Ontario in 2026?
Permit fees are set locally by each municipality. On January 1, 2026, fees rose by approximately 4.0% under the Building Code Act's annual indexation provisions.
Important: permit fees cover plan review and required inspections. They do not include development charges, which are separate and often significantly higher. However, under Bill 23 provisions, secondary suites and garden suites may qualify for reduced or waived development charges.
5. Timeline — How Long Does the Process Actually Take?
Under the 2024 Building Code, municipalities must review complete residential addition applications within 10 business days. But "complete" is the operative word — missing drawings pause the clock. Real-world timelines:
Simple renovations
No structural changes
Residential additions
With structural work
New construction
Custom home
Complex commercial
Multi-unit or commercial
6. Inspections — What Gets Checked and When
The permit holder (homeowner or builder) is responsible for booking inspections at each required stage. By law, the municipal building official must conduct the inspection within two working days of being notified. Typical inspection stages:
Excavation and footing inspection (before concrete pour)
Foundation wall and damp-proofing inspection
Framing inspection (structural, before insulation and drywall)
Plumbing and HVAC rough-in inspection
Insulation and vapour barrier inspection
Final / occupancy inspection
7. Common Mistakes That Delay Ontario Permits (And How to Avoid Them)
Submitting without structural engineering review
If your project touches a load-bearing wall, foundation, or second storey, get the engineering stamp before you apply — not when the municipality asks for it.
Assuming zoning compliance
Check setbacks, height limits, and lot coverage with your municipality before designing. A non-compliant design that reaches technical review wastes everyone's time.
Using drawings that aren't to scale
Hand sketches or unscaled drawings will be rejected. Every dimension must be measurable on the page.
Forgetting the energy compliance path
SB-12 documentation is required for every residential application — have your designer or engineer include it.
Applying under the wrong code edition
As of April 2025, all new applications must comply with the 2024 OBC. Old drawing sets will be returned.
Not booking inspections on time
If you pour a footing before the inspection, you're digging it up.
DIY permit drawings for complex work
Homeowners can apply for their own permits, but the drawings are held to the same standard. For structural work, professional drawings pay for themselves in avoided delays.
8. How MAY Engineering Simplifies the Permit Process
As a licensed Ontario engineering firm, we handle the two parts of the permit package that cause the most delays: structural engineering and permit-ready drawings. Our team prepares stamped structural drawings, architectural permit drawings, and energy compliance documentation — coordinated and submitted as one complete package. We also manage municipal revision cycles so you don't spend your project timeline going back and forth with the building department.
If you're planning a renovation, addition, custom home, or commercial build in Ontario, start with a complete application. It costs less than a revision cycle. Get in touch for a free project consultation.
Need permit drawings for your Ontario project?
MAY Engineering prepares code-compliant, municipality-ready permit packages — structural, architectural, and energy compliance in one submission.
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