Permit Answer · Home Addition Permit

Do I Need a Permit for a Home Addition?

Yes. A rear, side or second-storey home addition generally requires a building permit because it creates new floor area and changes the building envelope, structure and often its mechanical systems. Zoning should also be checked early because setbacks, height and lot coverage can control what can be built.

Direct answer: A home addition normally needs more than floor plans. The permit package can include a site plan, existing and proposed floor plans, elevations, sections, construction details and structural information, with HVAC, plumbing, grading, survey or energy documents added when required. Before the design is finalized, the property should be checked for zoning limits such as setbacks, building height and lot coverage. If the proposed addition does not comply with the applicable zoning by-law, a zoning approval or minor variance may be needed before or alongside the building-permit process.

Zoning first

Setbacks, lot coverage, height and other standards can limit the addition envelope.

Site plan

Shows the proposed addition in relation to the property and existing building.

Permit drawings

Floor plans, elevations, sections and construction details describe the addition.

Supporting disciplines

Structure, HVAC, plumbing, grading, survey or energy information may be required.

Property and municipality still matter

This answer is a practical starting point, not a permit decision for every property. Zoning, existing conditions, applicable law, project size and the municipality’s current application guide can change what is required.

Related 828 Design service

Home Addition Permit Drawings →

Reviewed against current municipal permit guidance: August 2026. Requirements are confirmed for the actual property and project before design/submission.

Need drawings for this project?

Send the property address, what you want to build and any survey, existing drawings, photos or municipal comments you already have.