Renovations, additions and basements

Interior renovations and basement finishing sometimes require a permit. Additions to an existing home footprint require a permit. Review the guidelines to understand when a permit is required.

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When a permit is required

Interior renovations that require a building permit include:
  • finishing an unfinished space in a home, such as a basement
  • adding or removing walls
  • material changes to alter the insulation type or value of walls
  • structural changes
  • addition or change of plumbing, including the installation of a fixture where a rough-in already exists
  • change of current use
  • addition to an existing footprint
  • creating a second unit

Building additions must meet all zoning requirements. Visit the Zoning bylaw page to learn more.

How to submit an application

Prior to submission, ensure that all necessary and applicable permissions and approvals are met.

A complete application must be submitted with all the required forms, documents and applicable drawings. Building permit fees (see below) are required at the time of submission. Additional fees such as development charges and parkland will be calculated and invoiced at permit issuance.  

Visit the building permits page to submit your application. Read below for requirements to submit a permit application for a renovation, addition or basement.

Requirements to submit a permit application

You need a set of drawings and the following forms to make an application:

Designer qualifications

Qualified individuals who may design a renovation or finished basement:

  • an architect, professional engineer or qualified designer with Building Code Identification Number (BCIN) is permitted to take responsibility for the design
  • the homeowner is permitted to prepare and take responsibility for the design of renovations, additions and finished basements of their home

Drawings and documentation

Drawings drawn to scale, for example 1/4 inch = 1 foot, are required to be submitted and are to include:

  • property survey or site plan illustrating the lot size with dimensions, location and size of proposed addition (including dimensions to property lines), and all existing buildings or structures on the property.  
  • floor plans (foundation and all floor levels) fully dimensioned with room names, framing information, structural information, door and window sizes and lintel sizes 
  • location of plumbing fixtures 
  • cross section noting materials and dimensions 
  • truss layout sealed by professional engineer (if proposed) 
  • exterior elevations showing heights, grades, exterior materials, opening sizes, roof slopes and materials 
  • HVAC and Mechanical Summary Form (also required where an addition increases existing area by 15% or more)
  • where the dwelling unit has 6 or more bedrooms a Part 6 design is required for HVAC and mechanical
  • Helical Pile torque calculations and manufacturers technical documentation; the design must be stamped by a professional engineer when supporting more than a deck

Fees and timelines

Permit type Fee per square foot
Renovations in a previously finished space $0.49
Renovations in a shell or unfinished space $0.35
Fee per square foot for an addition $1.12
Fee for a second unit $0.49
Permit to finish or renovate any area of basement $280.00

The typical time to review renovations and finished basements is 10 business days. Applications are processed within the time frames mandated by the Ontario Building Code and are based on project type.

Plan and book inspections

Once your building permit has been issued you will have the following inspections: 
Note: Approved drawings must be available on site for all inspections. 

Typical inspections include: 

  • commencement of construction 
  • footing (before concrete poured) 
  • plumbing underground, rough-in and/or final 
  • framing 
  • insulation 
  • air barrier 
  • final building inspection 

Please review your issued permit card for a list of applicable inspections. 

Call the small building inspection line at 519-747-6120 to book your inspections. 

Getting an electrical permit