Building Permit Requirements Ontario 2025 — Structural Engineering Guide

Getting a building permit in Ontario requires specific documentation — and structural engineering drawings are often the most critical component. Here's a complete guide to what you need in 2025.

When Do You Need a Building Permit in Ontario?

A building permit is required in Ontario for most construction, renovation, and demolition work, including:

• New home construction
• Home additions and second-storey additions
• Removing load-bearing walls
• Basement lowering and underpinning
• Legal basement suite conversions
• Detached garages and accessory structures over certain sizes
• Decks above 600mm from grade or over 10 sq metres
• Garden suites and laneway suites

What Structural Engineering Documents Are Required?

For structural projects, your permit application typically requires:

• P.Eng.-stamped structural drawings — showing beam sizes, column locations, connections, and load paths
• Structural calculations — demonstrating the design meets Ontario Building Code requirements
• Site plan — showing property boundaries and building footprint
• Architectural drawings — floor plans, elevations, and sections (coordinated with structural)

How Long Does It Take to Get a Building Permit in Ontario?

Review times vary by municipality and project type. General timelines in 2025:

• Wall removals, small accessory structures: 10–15 business days
• Home additions, underpinning: 4–6 weeks
• New custom homes, garden suites: 6–10 weeks

How to Get Approved on the First Submission

The most common reason for permit delays is an incomplete or inaccurate submission. AMGH Engineering prepares complete packages that address the requirements upfront. Our approach: detailed drawings, clear calculations, and proactive coordination with your architect or designer to ensure consistency across the full submission package.