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When is a Building Permit Required?

A building permit is required for:

  • Any structure occupying an area greater than 10m2 (108 sqft) consisting of a wall, roof or floor, or a structural system serving the function thereof, including all plumbing, works, fixtures and service systems that lead to/service that structure;

  • any structure occupying an area of 10m2 (108 sqft) or less that contains plumbing, including the plumbing that services/leads to that structure;

  • any addition to an existing building;

  • plumbing not located within a structure;

  • replacement of a fire alarm panel or control unit;

  • a sewage or septic system;

  • “designated” structures as per the Ontario Building Code; (Division A-, and;

  • any alterations to an existing building which affect the structural design of the building including mechanical, electrical*, plumbing services (no limit on size of building), fire separations, egress (exits), fire protection/suppression systems and/or changing the use of buildings or parts of a building.

*Note: Contact the Electrical Safety Authority (ESA) for electrical permit information.

See Below for More Information

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  • Residential Examples
    • Decks greater than 600mm (24 inches) above ground or serving the principal entrance for dwelling units
    • Interior structural alterations
    • Adding or removing most walls, (i.e., creating different room sizes and/or uses)
    • Porches
    • Basement or main floor walkout alterations
    • Sunrooms, solariums
    • Replacement of brick veneer
    • Carports, attached or detached garages, sheds
    • Dormers or finishing of attic space
    • Installation of irrigation systems
    • Additions
    • Installation, repair of storm, sanitary and water service
    • Finishing a basement or a portion thereof
    • Furnace and ductwork replacements
    • Installation of plumbing cleanouts
    • Conversion from septic to sanitary sewer
    • Plumbing and/or drains (except replacing fixtures)
    • Insulating exterior walls when exterior or interior cladding is removed
    • New or structural alterations to windows or doors
    • Installation or repair of private sewer systems and water service
    • Backflow preventers for lawn irrigation systems
    • Structural work related to fire damage


  • All Other Buildings (Commercial, Industrial, Institutional)
    • Change of use (where construction is proposed or the change constitutes an increase in the hazard index)
    • Interior renovations within a floor area affecting fire separations, exits or structural capacity
    • Interior finishing of shell buildings for tenants (ie. occupancies in commercial or industrial malls and office buildings, etc.)
    • Fire and water damage affecting interior renovations within a floor area affecting fire separations, exits or structural capacity
    • Additions to any building having a combined area of 10m2 (108 sq. ft.) or more
    • Installations and major alterations of sprinkler, standpipe, fire alarm or mechanical (HVAC) systems
    • Plumbing installation and alterations, except replacement of fixtures
    • Installation or replacement of storm and sanitary sewers, water service (ie. catch basins, weeping tile, clean-outs, change from septic system to sewers)
    • Installation and repairs to sewage systems (septic systems and holding tanks)
    • Installation of backflow preventers
    • Retaining walls exceeding 1 metre (3 ft.- 3 inches) in exposed height adjacent to public property, to an access to a building, or on private property to which the public is admitted
    • Tents greater than 60m2 (645 sq. ft.)​
  • Projects that Do Not Require a Building Permit
    • Fences (other than for swimming pools)
    • Decks not forming part of a principle entrance to a dwelling unit and less than 600mm (24 inches) above grade
    • Asphalt roof shingling
    • Eaves troughs
    • Minor repairs to masonry
    • Damp proofing basements
    • Air conditioning units or heat pumps added to existing forced-air systems
    • Kitchen or bathroom cupboards without plumbing
    • Free-standing satellite dishes
    • Replace existing forced-air furnace (no duct work alterations)
    • Replacing siding or windows (provided there are no structural changes)
    • Pool heaters
    • Painting and decorating
    • Landscaping
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