Do I need a building permit for a home addition in Ottawa?

Yes, in almost every case. The City of Ottawa's list of building permit projects names one- and two-storey additions, and its rule is that "a building permit is required for the construction of a new building, an addition, or alteration of any building or structure with a building area of over 10 square metres (approximately 108 square feet)." The same list includes adding or removing walls, new windows where there were none before, enlarging or relocating a window or door, plumbing alterations or extensions (except replacing existing fixtures), and structural repairs or alterations. Most addition projects touch several of these at once.

If you are unsure whether your project needs a permit, contact Building Code Services (buildingpermits@ottawa.ca) before you start. Work that is exempt from a permit still has to comply with the Building Code and the Zoning By-law. Work that is exclusively electrical doesn't need a building permit, but it does go through the Electrical Safety Authority.

What the application needs. Expect to submit drawings showing floor plans, elevations, sections and a site plan that places the addition relative to the property lines. Your designer will confirm what the City needs for your project and who can prepare it.

Fees. Under the 2026 schedule, alterations, renovations and additions to existing buildings cost $12.75 per $1,000 of construction value (materials, labour, overhead and professional fees), with a $117 minimum. A $150,000 valuation works out to about $1,913. The City confirms how your project is valued.

Zoning approvals. Your zoning sets maximum height, lot coverage and setbacks. If the addition doesn't fit, a minor variance from the Committee of Adjustment is how you seek relief. The 2026 urban fee totals $3,759 (rural $4,064). Ottawa has two zoning by-laws in effect while appeals are resolved, so check your property's zone.

Heritage. If your property is designated heritage or sits in a Heritage Conservation District, the City must approve alterations, including the construction of additions.

Who is responsible. The City states that it is the owner's responsibility to make sure a permit is obtained when required, and that both the owner and the builder or contractor are responsible and equally liable. Building without one can lead to orders to stop work or remove it, and problems when you sell.

Related trade rules. Electrical work needs an ESA notification and is done by an ESA-licensed electrical contractor, and gas work is done by a TSSA-certified gas technician. Ask each contractor whether they have WSIB coverage or are exempt.

You can browse addition contractors in the Ottawa Construction Network directory at justynrookcontracting.com and ask each how they handle the permit.

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Looking for experienced contractors? The Ottawa Construction Network connects homeowners with qualified professionals:

• Luxe Painting and Renovations
• RenoMotion Inc.
• Demontigny Carpentry
• Diamond renovations
• Pure Flow Water Solutions inc.