Questions and Information About Building Permits

What is a Building Permit?

A building permit is formal approval to construct, add to, or remove a building on your property.

Why do you need a building permit?

Building permits allow us to protect the interest of both individuals and the community as a whole.  By reviewing and approving plans before any work is done, we can ensure that buildings comply with:

• the Ontario Building Code, which sets minimum standards for design and materials;
• the Ajax Zoning by-law and its controls on buildings and uses that are suitable to the area; and
• other health and safety regulations.

How does a building permit help me?

Permits help make sure construction meets the standards set out in the Ontario Building Code. If the work does not comply with the Code, the value of your investment could be reduced. Building permits help protect your health, safety and welfare by having trained professionals review your plans and inspect construction.

When do I need a building permit?

Here is a list of typical projects that require a permit:

• Construction of any new building over 10 square metres (108 square feet) in area, including a new home, detached garage, playhouse or shed.
• Addition of a carport, garage, porch or room(s) to an existing home.
• Construction or finishing of rooms in the basement or attic.
• Any structural work including alterations to interior partitions, installation of new skylights, windows or doors requiring enlargement of the existing opening.
• Decks attached to a house and/or more than 600mm (23 5/8") above finished grade.
• Raising a house to provide a full basement.
• Excavating a crawl space to provide a full basement.
• Fireplaces and other heating appliances including the replacement of furnaces and ductwork.
• Basement walkouts.
• Plumbing and/or drains.
• Permanent ground or fascia signage.
• Adding in an accessory apartment to a single family dwelling under the Ontario Building Code.
• Upgrading an accessory apartment under the Ontario Fire Code.
• Demolishing a building.
• Building a sunroom on your house.

Note: For buildings over three stories and/or more than 600 square metres (6,460 square feet) in area, a professional engineer or/and an architect is required to design your building, prepare plans and drawings, and carry out the general review of the construction.

What projects do not require a building permit?

A building permit is not required for an accessory building or structure that is not attached to the house, and which measures less than 10 square metres (108 square feet) in area. An accessory building is any building or structure other than the house. The following is a list of projects that do not require a building permit:

• Air conditioning units and heat pumps added to existing systems.
• Painting and decorating.
• Asphalt roof shingling.
• Eavestroughs.
• Kitchen or bathroom cupboards without plumbing.

Note: Although a building permit may not be required, you must still comply with the requirements of the Zoning By-Law. Contact 905-619-2529 ext. 222 for zoning requirements.

Are there any other permits or inspections required in addition to a building permit?

Yes, in addition to the building permit you may be required to obtain one or more of the following:

• Electrical Permit: To get a permit application and inspection, call Ontario Hydro at 1-800-305-7383.
• Engbridge Gas Distribution:  To arrange inspection of a gas appliance (i.e. furnace, hot water heater) call 416-447-4911 or 1-888-447-4911.
• Region of Durham Health Department approval.
• Toronto Region Conservation Authority approval.

What happens if you don’t get a building permit?

Anyone who is charged and found guilty of building without a permit can be fined up to $25,000 for a first offence and up to $50,000 for later offences.

Fines can also be imposed if you don’t follow an order.

When do I call for inspections?

During construction, several mandatory inspections are required to ensure that all work is done according to the reviewed drawings and the OBC. The following are the required inspections during the course of construction for new residential buildings and additions:

• Footings: Prior to pouring concrete footings.
• Foundation Pre-backfill: Upon completion of the foundation and prior to backfilling.
• Framing: Completion of total framing, including electrical work, plumbing, central vacuum and heating rough-in.
• Insulation, Air and Vapour Barrier: Completion of insulation, air and vapour barriers, prior to applying the interior finishes.
• Fire Separations:  The framing for the walls, floors and shaft fire separations, closures and fire stopping are completed, prior to applying the interior finishes. 
• Plumbing Outside Services: Installation of building drains and water supply to building.
• Plumbing Inside Services: Installation of drains and water supply under the basement floor.
• Plumbing Rough-in: Prior to installing insulation.
• Plumbing Final:  Installation of hot water tank and all required plumbing fixtures, prior to occupancy.
• HVAC Rough-in:  Prior to installing insulation.
• Final HVAC:  Installation of furance and all required systems and grilles, prior to occupancy.
• Final Interior: Completion of finishes, handrails, guards, smoke alarms and gas proofing, prior to occupancy.
• Final Exterior: Completion of all exterior work including site grading, caulking, balconies, landings, and finish materials.

Where do I apply for a permit or get more information?

For a permit application or more information concerning building permit requirements contact or visit Planning and Development Services at 65 Harwood Ave. S. You can call us at 905-619-2529, ext. 216, 254 or 264. Our office hours are 8:30 am to 4:30 pm Monday to Friday. To book a building inspection call 905-619-2529 ext 285.