Small Residential Interior Alterations

Service Description

A building permit for an interior alteration to a small residential building, such as a detached house, semi-detached house or townhouse is required.

Service Outcome

Building Permit

General Information

All drawings to be drawn on standardized sized sheets, drawn to scale, fully dimensioned, signed and dated.

If drawings were prepared by a qualified designer (as defined under Div. C, Part 3, Section 3.2 of the Ontario Building Code), drawings must include the designer's name, registration number, qualification identification number, signature, and stamp/statement that the person has reviewed and taken responsibility for the design activities.

Required Documentation

Floor Plans (example Site Plan Checklist Below)

  • Fully dimensioned, for each level showing existing & proposed uses of all spaces, including location of smoke alarms & carbon monoxide detectors and all plumbing fixtures. 
  • Provide existing/proposed construction with foundation & exterior wall information, showing interior partitions and structural framing above.


  • Cross section(s) to show existing/proposed building construction and specifications of all floor, wall, & roof assemblies. 
  • Provide footing & foundation wall details including height of exterior grade above basement floor. 
  • Show floor to floor, floor to ceiling and overall building heights. 
  • Detail stairs, landings, guards & handrails.

Construction Details and Notes

  • Building materials & specifications of all wall, floor, and roof assemblies with typical wall section and typical roof detail. 
  • Provide guard details including connection detail.

Site Plan required for Second Suites or New Openings

Where the proposed alterations include a new second suite or where new openings are proposed, a site plan is required showing:

  • Survey or site plan showing property lines, lot area, right-of-way or easements (referenced to a current survey)
  • Location of existing/proposed buildings with overall dimensions and include setback dimensions to property lines and adjacent buildings.
  • Summary of permitted and proposed zoning provisions to include lot area, building area (GFA), coverage, and grade elevations to confirm height.
  • Indicate dimensioned parking areas, driveways, hard & soft landscape treatments, accessory structures (sheds, decks, detached garages, etc).

Mechanical and Plumbing Requirements (if Applicable)

If your project includes a Mechanical (HVAC) please submit the Energy Efficiency Design Summary Form and Mechanical Ventalation Design Summary (below) with your building permit application.

Plumbing and Drain Permits

If your project includes plumbing or drain and water service elements please submit a Plumbing Application (below) with your building permit application. No plans required unless the project includes a reverse sloped driveway. If the project includes a reverse sloped driveway then drawings must be submitted showing details of reverse sloped driveway and drain plan.

Required Forms

Building Application
Mechanical Ventilation Design Summary
Plumbing Permit Application