Accessory Structures

All accessory structures in the Town of Whitby, such as sheds or detached garages, are regulated under the Zoning By-law and may be subject to requirements in the Ontario Building Code.

Apply for a building permit

If your accessory structure, other than a shed, is larger than 10 m² in size, you'll need to get a building permit before you begin construction.  If your shed, that is accessory to a dwelling, is larger than 15 m² in size and/or greater than one storey in building height, then you'll need to get a building permit before you begin construction.  Learn how to apply for a building permit. Even if a building permit is not required, all accessory structures must comply with the provisions of the Zoning By-law.

Building and zoning requirements

The Zoning By-law sets out the building standards for all accessory structures. When designing an accessory structure make sure to follow these general guidelines and requirements:

• If an accessory structure, other than a shed, is less than 10 m² in size, you don't need a building permit, but you must still follow the provisions in the Zoning By-law;
• If the shed, that is accessory to a dwelling, is less than 15 m² in size, you don't need a building permit, but you must still follow the provisions in the Zoning By-law;
• Generally, accessory structures in residential zones shall not exceed 4.5 m in height;
• Accessory structures are only permitted in a side yard or back yard within residential zones;
• Accessory structures shall be setback a minimum of 0.6 m from any interior or rear lot line.  Eaves and roof overhangs may encroach into the setback a maximum of 0.3 m.  Additional setbacks shall be required where an accessory structure abuts an exterior lot line in accordance with the Zoning By-law;
• If an accessory structure has windows that face neighbouring properties or streets, there may be additional setback requirements and will be reviewed during the building permit process;
• Accessory structures shall not include a home based business.  This also applies to accessory structures that contain an additional dwelling unit (ADU); and 
• Review the applicable Zoning By-law to learn more about other required provisions that will apply to accessory structures (i.e. lot coverage, building height, setbacks, number of structures, etc.)

What is an accessory structure?

Accessory structures can be anything that is detached from the main building on the property and can include:

• Sheds
• Detached garages
• Gazebos
• Pool houses