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Residential Decks for Single Detached Dwellings

General Regulations:
  • Deck means a floor-like structure without a roof having a foundation to hold it erect, and attached to or abutting one or more walls of a building, with or without direct access to the ground, the floor of which is greater than 0.6m above finished grade and which is designed and used as a sundeck, but shall not include a landing or stair.
  • Building permits are required for decks if the deck surface is 0.6m (23 5/8") or more above finished grade level or where full depth foundations are required, such as when decks are attached to a building having full depth foundations.
  • Decks attached to a building with a full foundation are typically required to be supported on a foundation (such as posts) extending not less that 1.5m (5'0") below grade
  • Decks independent of the dwelling may be built with on-grade structural supports
  • Guardrails must be provided where the Deck surface is 0.6m (23 5/8") above the adjacent surface or grade
  • Required guardrail balustrades must be vertical, non-climbable, have no openings exceeding 0.1m (4") and meet strict "new in1998" mandatory requirements of the Ontario Building Code for structural requirements
  • Minimum Guardrail Heights (based on deck height) are as follows:
Deck Height           
Below 0.6m (23 5/8") No guardrail required
Up to 1.8m (5'11") 0.9m (36") guardrail
Above 1.8m (5'11") 1.07m (42") guardrail            r> Where a deck is to be added to a single detached dwelling constructed prior to March 16, 1987 which has less than the required mimimum side yards according to the Zoning By-law, the deck shall be located not closer to the side lot lines than the dwelling or 0.6m (23 5/8") from the side lot line, whichever is greater.

Do I need a building permit?

  • Yes, if the deck surface is 0.6 metres (23.6 inches) or more above the finished grade level
  • Yes, if full-depth foundations are required

Building Permit Application Form Adobe PDF, 3 pages, 69KB

What do I need to provide to the city in addition to the completed Building Permit application?

  • Schedule 1: Designer information, completed, with designer’s signature Download Schedule 1  Adobe PDF, 1 page, 33 KB
  • Written authorization from the owner of the building
  • Proof of ownership (either a property deed or tax notice)
  • Two sets of deck floor plans
  • Two sets of deck cross-section plans
  • Current site plan or survey, indicating existing buildings and the proposed structure
  • Required fee: set at $10 per $1,000 of construction value, minimum fee is $50
  • Other approvals as needed (e.g. Thunder Bay Hydro) – see below for more information

What other information do I need?

  • If there is a septic tank or field near the building site, contact the Thunder Bay District Health Unit, Sewage Systems and Land Development Program, at (807) 625-7991 for information on clearances.
  • If you are carrying out electrical work as part of the project, you must contact the Electrical Safety Authority at www.esasafe.com or call 1-877-372-7233 for information and inspections. Ontario One Call logo

Excavations - call before you dig!

At least five days before you start digging, contact Ontario One Call to arrange for the location of underground utilities.

Dig safe - it's the law.

More information on Ontario One Call.

Inspections

Once you receive a building permit, it is your responsibility to arrange for building inspections.

Call (807) 625-2570 (North Ward) or 807-625-3124 (South Ward) at least 48 hours in advance to book an appointment. You can call at any time to leave a message.

In most cases, there will be only one final inspection when the deck is complete with foundation, flooring, stairs, guardrails, and balustrades.

City of Thunder Bay

Building Services Division

Address:

Victoriaville Civic Centre

111 Syndicate Avenue S P.O. Box 800             Thunder Bay ON P7C 5K4

Tel: (807) 625-2574
Fax: (807) 623-9344
Hours: Counter Service Only Available on Monday, Wednesday and Friday - 8:30 am to 4:30 pm