When building permits are needed and when they’re not in Mississauga

Published April 11, 2022 at 3:17 pm

home improvement MIssissauga

If you’re planning on home improvements in Mississauga like building a new deck, shed or refinishing a basement, you might need a building permit.

Where building permits are not required and where they are in Mississauga

Most renovation, construction or demolition projects require a building permit before you start construction.

A building permit is a document issued by municipalities, like Mississauga, and it is necessary for projects that involve constructing, changing or adding to a building’s structure.


A permit is required prior to building, demolishing or installing any of the following:

  • Accessory structure like a shed, cabana or gazebo greater than 10 square metres, or any size if it contains plumbing
  • Addition to an existing building
  • Backflow preventer
    • Backflow prevention devices are required under the authority of the Region of Peel’s Backflow Prevention By-law 10-2017 and the Ontario Building Code. The purpose of this by-law is to prevent backflow into the Region’s Municipal Drinking Water System to maintain clean and safe drinking water. For more information on the By-law and the Backflow Prevention Program, please visit the Region of Peel website.

  • Balcony – either constructing one on a house, apartment or condo, or replacing or repairing guards on an apartment or condo
  • Basement including:
    • Finishing a basement to create rooms or living space
    • Basement apartment (also known as second unit)
    • Excavating a increase existing headroom
  • Below grade entrance or basement walkout
  • Building or structure greater than 10 square metres, or any size that contains plumbing
  • Change the use of a building
  • Communication or transmission tower or antenna greater than 16.6 metres high above ground level
  • Deck greater than 0.61 metres (2 feet) high
  • Detached garage
  • Doors – either adding a new door or increasing the size of an existing one
  • Dormers
  • Dust collector
  • Fire alarm system
  • Fire damage repair
  • Fire suppression system
  • Furnace replacement that’s of a higher efficiency than existing
  • Furnace ducts being altered
  • Garage
  • Gas fireplace used for heating
  • Generator connected to life safety equipment like fire alarms or emergency lighting
  • Geothermal system
  • Heating, ventilation and air conditioning (HVAC) system
  • Interior alterations
  • Kitchen exhaust
  • Loading dock
  • Maglocks
  • Mezzanine
  • Parking structure, like a multi-level parking lot
  • Patio for a restaurant
  • Plumbing fixture like a sink, tub, toilet, or shower that’s added, removed or relocated
  • Plumbing drainage – install, replace or repair
  • Porch that’s covered
  • Private sewage system – install, replace or repair
  • Re-cladding a building with new material, for example changing siding to brick
  • Roof extensions or alterations to increase the height or change the slope
  • Rooftop HVAC replacements
  • Satellite dish attached to a building, or a dish with an area equal to or greater than 5 square metres
  • Second unit, also called a basement apartment
  • Sewer systems – install, repair or replace
  • Shoring and excavation
  • Site servicing
  • Skylights
  • Solar panels
  • Spray booths
  • Sprinklers
  • Sump pump on a property in the Foundation Drainage Collection (FDC) System area
  • Temporary tents greater than 60 square metres
  • Underpinning foundation walls
  • Weeping tile repairs or changes on a property in the Foundation Drainage Collection (FDC) System area
  • Windows – either new or increasing the size of an existing window
  • Wood burning fireplace

Projects that don’t need a permit

  • Accessory structure like a shed, cabana or gazebo less than 10 square metres that does not contain plumbing
  • Cabinetry or cupboards
  • Concrete pad
  • Damp-proof a basement
  • Deck less than 600 mm (2 feet) in height
  • Decorations
  • Doors – replacing an existing one with the same size
  • Driveway – either widening or resurfacing
  • Eavestrough, if the drainage is contained within the property
  • Fence
  • Fireplace that’s decorative gas
  • Gazebo less than 10 square metres, that does not have plumbing
  • Landscaping work
  • Minor masonry repairs
  • Painting
  • Parking lots without catch basins that are new, expansions, or painting new lines
  • Plumbing fixture replacement in the same location, for example a sink, tub, toilet, or shower
  • Re-cladding a building with the same material, for example siding to siding, or brick to brick
  • Re-shingling a roof
  • Retaining wall less than one metre high
  • Shed less than 10 square metres with no plumbing
  • Windows – replacing an existing one with the same size
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