Building or Renovating - Town of Ajax

Building or Renovating

Before starting a construction project, inside or outside your home, consult with Building Approvals first to determine if a building permit is required.

Construction that Requires a Building Permit

  • Adding a bedroom in the basement
  • Addition to a building
  • Attached garage, carport, awning, pergola  or other roof structure of any size
  • Creating an accessory apartment (a.k.a. in-law suite, basement apartment, granny flat or nanny suite)
  • Decks or platforms greater than 0.6m (23-5/8") above grade or attached to another structure
  • Detached garage, carport, shed, awning, gazebo or other roof structure 10 m2 (107.6 ft2) and greater in building area (measured to the outside face of exterior walls)
  • Demolition of a structure greater than 10 m2 (107.6 ft2) in building area
  • Excavating a crawl space to provide a full basement
  • Finishing the basement of a house
  • Industrial, commercial, institutional and multi-residential construction or alterations or changes of use
  • Installing a new window or door, or when increasing the size of the existing opening
  • Installing heating appliances, including modifying ductwork
  • Plumbing fixtures added or relocated
  • Re-insulating walls, ceilings or floors
  • Removing a load bearing wall, column, lintel or beam
  • Removing a non-load bearing wall in a dwelling unit
  • Residential dwelling unit
  • Retaining wall that is greater than 1 m (3'-3") in height
  • Septic system installations and alterations
  • Signs, permanent
  • Site servicing (water or sewer lines) for all building types
  • Solar Panels that are mounted to a building or have a face area of 5 m2 (54 ft2) or greater
  • Tent or group of tents that is, more than 60 m2 (646 ft2) in aggregate ground area, attached to a building, or constructed within 3 m (9'-10") of any structure
  • Upgrading an accessory apartment under Section 9.8 of the Ontario Fire Code Applies only to accessory apartments built prior to July 14, 1994.
  • Woodstove or woodburning fireplace

Electrical work is not reviewed or inspected by Building Approvals. For electrical permits contact the Electrical Safety Authority at 1-877-372-7233.

Construction that Does Not Require a Building Permit

  • Door and window replacements (within the existing opening, where no structural members are changed)
  • Eavestroughs
  • Fence (but must comply with zoning regulations)
  • Gas fireplace
  • Installing air conditioning units and heat pumps to existing systems
  • Installing new shingles on existing roof
  • Painting, wall papering, tiling, carpeting, cabinets, countertops, and similar finish work
  • Replacing a plumbing fixture (i.e. toilet, bathtub or sink) with a new fixture in the same location
  • Structure less than 10 m2 (107.6 ft2) measured from the outside face of walls (with no plumbing)

Although a building permit may not be required, you must still comply with the requirements of the Zoning By-Law. Contact 905-683-4550 for zoning requirements.

Consequences for Not Obtaining a Building Permit

Anyone who is charged and found guilty of building without a permit can be fined up to $50,000 for a first offence and up to $100,000 for later offences.

Fines can also be imposed if you do not follow an order.

For more information, please contact us at 905-619-2529 ext. 3652.