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 |
Required Guardrail 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 |
- Built-in perimeter seating requires backrest heights and construction based on guardrail requirement. The guard height shall be measured from the seat surface.
| In April 1998, the Ontario Building Code implemented strict new requirements for guardrail construction. It is now only allowable to construct 2 types of wood guardrails, the 'Cantilever Picket System' or the 'Post and Rail System' (details are available from our office), otherwise the guardrail must be designated by a professional engineer registered in the Province of Ontario. |
| Regulation |
R1/R2 |
RS/RE/RU |
|---|---|---|
| Maximum Lot* Coverage, All Buildings |
35% |
– |
| Front Yd./Rear Yd. (b) |
6m - 9m |
10m |
| Interior Side Yard (no attached garage or carport) |
One Side |
3m (10 ft) |
| Interior Side Yard (with attached garage or carport) |
One Side |
3m (10 ft) |
| Exterior Side Yard (d) |
3m (10 ft) |
6m (20 ft) |
Notes:
a) Decks 0.6m (23 5/8") or more in height are included in lot coverage calculations.
b) Typically, both front and rear yards must be at least 6m (19’ 10”), and a combined front and rear yard of 15m (49’ 3”) shall be maintained. *Some exceptions apply such as in full lots in older neighbourhoods
c) A deck may project into a required front or rear yard to a maximum distance of 1.5m (4’ 11”)
Non-Complying Use (s. 5.10)
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
Adobe PDF, 1 page, 38 KBWhat 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.
- Call before you dig! Contact the following agencies to check the location underground services:
- Gas lines: 1-800-400-2255
- Thunder Bay Hydro: (807) 343-1111
- Sewer and water: (807) 625-2195
- Bell Telephone: 1-800-465-6924
- TBayTel: (807) 684-8344
- Cable television: (807) 767-4422
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 BayBuilding 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 |
