<p>A home addition is one of the most complex and rewarding renovations you can undertake. Whether you are adding a main floor family room, a second storey, or a garage with living space above, the planning process is critical to a successful outcome.</p><h2>Types of Home Additions</h2><ul><li><strong>Bump-out addition</strong> — Extends an existing room by a few feet. Lower cost, minimal disruption.</li><li><strong>Single-storey addition</strong> — New room or suite added to the footprint of the home.</li><li><strong>Second storey addition</strong> — Adds a full floor above the existing structure. Maximizes space without expanding the footprint.</li><li><strong>Garage conversion or addition</strong> — Converts or builds above a garage for additional living space.</li></ul><h2>Zoning and Setback Rules</h2><p>Before you design anything, check your municipality's zoning bylaws. Every property has setback requirements — minimum distances from property lines — that limit where and how large an addition can be. Your contractor or an architect can help you understand what is possible on your specific lot.</p><h2>The Permit Process</h2><p>All home additions in Ontario require a building permit. For a second storey addition, you will also need engineered drawings confirming the existing foundation and structure can support the additional load. Budget 4–8 weeks for permit approval.</p><h2>Home Addition Costs in Ontario (2026)</h2><ul><li><strong>Bump-out (under 200 sq ft)</strong> — $60,000 to $100,000</li><li><strong>Single-storey addition (400–600 sq ft)</strong> — $150,000 to $250,000</li><li><strong>Second storey addition</strong> — $250,000 to $450,000+</li></ul><h2>What to Expect During Construction</h2><p>A home addition involves opening up your existing home — cutting through exterior walls, tying into existing mechanical systems, and integrating new construction with old. Expect some disruption to your daily routine, particularly during the structural phase.</p><h2>Choosing the Right Contractor</h2><p>Home additions require a contractor with specific experience in structural work, not just interior finishing. Ask to see examples of completed additions and speak with past clients about how the project was managed.</p><h2>Start With a Consultation</h2><p>MDECO has completed home additions across Ontario. Contact us to discuss your project and get a detailed assessment of what is possible on your property.</p>