Permit guideMarkhamBuilding PermitsAdditional Residential Units
Coach house, garden home and three-unit building permits
Constructing a coach house or garden home, or converting an existing single or semi-detached house to a three dwelling unit building, requires a housing (HP) permit.
Check whether you need a permit
- Coach houses and garden homes are both considered accessory buildings to a house on the same property.
- A coach house is a dwelling unit where the majority of the unit is located above a detached garage located in the rear yard of a property that is accessed by a lane.
- A garden home is a dwelling unit located in an accessory building that is in the rear yard of a property.
- Constructing a coach house or garden home requires a housing (HP) permit.
- A three (3) dwelling unit building is a building with three independent dwelling units. When converting an existing house into a three dwelling unit building the renovated building is considered a multiple-unit residential building.
- Converting an existing single or semi- detached house to a three dwelling unit building requires a housing (HP) permit type.
- If you are unsure of what building permit type is most appropriate for your project, please contact the Building Counter at 905.475.4870 to confirm before submitting your application.
- Only if you are constructing a coach house or garden home
Coach house or garden home: guide, forms and plans
Constructing a coach house or garden home requires a housing (HP) permit.
Guide for Homeowners
Our Coach Houses and Garden Homes Guide for Homeowners outlines the requirements for constructing a new coach house or garden home on your property.
Required Forms
General Information
These requirements apply to all building permit types.
- All submitted drawings must be on standardized sized sheets, drawn to scale, fully dimensioned, signed and dated.
- Drawings by a designer must include: the designer’s name, designer’s contact information, qualification identification number (if applicable), signature, and stamp / statement that the person has reviewed and taken responsibility for all design activities.
Required Documentation
- Approval Documents required by Applicable Law
Site plan
- Zoning Summary (permitted / proposed)
- Property lines referenced to a current survey
- Location of all proposed & existing buildings
- Overall dimensions of all buildings (width / length)
- Proposed finished first floor elevations
- Location of limiting distance line between existing house and coach house / garden home
On-site Sewage System (for properties served by private systems)
- System drawings & details
- Statement of Design
Architectural Plans
- Floor plans of every floor level (specify rooms).
- Label use of each space, provide dimensions, ceiling height
- Show window and door location and sizes
- Indicate location of fire separations
- Show electrical lighting, control switches and outlets, interconnected smoke alarms, and when required, the location of battery powered emergency lighting units.
- Building elevations for coach house / garden home, including limiting distance calculations.
- Building elevations for exposing building face of existing house that is facing the coach house / garden home
- Sections and Wall / Celing / Fire Separation Construction Details
- Construction Details of Egress Windows
- Details and construction notes / specifications
Structural (may be incorporated into Architectural Plans)
- Footing / Foundation design
- Floor framing plan (including posts, beams, joists, lintels)
- Roof framing plan (including posts, beams, joists, lintels)
Mechanical (HVAC/Plumbing) Plans (may be incorporated into Architectural Plans)
- location of all heating supply outlets and return air grilles, exhaust air intakes, duct-type smoke detectors
- Provide exhaust fans over ranges, within bathrooms and all rooms not equipped with a window providing natural ventilation to the outdoors
- Show location of plumbing fixtures
- Only if you are converting an existing single or semi-detached house to a three dwelling unit building
Three dwelling unit building: guide, forms and plans
Converting an existing single or semi- detached house to a three dwelling unit building requires a housing (HP) permit type.
Guide for Homeowners
Our 3 or 4 Dwelling Unit Guide for Homeowners outlines the requirements for converting a single or semi- detached house into a three or four dwelling unit building.
Who prepares the drawings
- The drawings for this type of project must be prepared by a registered designer with a Building Code Identification Number (BCIN) qualified in Small Buildings and Building Services, a licensed Architect, a Professional Engineer or a combination of these.
Required Forms
General Information
These requirements apply to all building permit types.
- All submitted drawings must be on standardized sized sheets, drawn to scale, fully dimensioned, signed and dated.
- Drawings by a designer must include: the designer’s name, designer’s contact information, qualification identification number (if applicable), signature, and stamp / statement that the person has reviewed and taken responsibility for all design activities.
Required Documentation
- Approval Documents required by Applicable Law
Site plan
- Zoning Summary (permitted / proposed)
- Property lines referenced to a current survey
- Location of all proposed & existing buildings
- Overall dimensions of all buildings (width / length)
- Proposed finished first floor elevations
On-site Sewage System (for properties served by private systems)
- System drawings & details
- Statement of Design
Architectural Plans
- Existing floor plans
- Floor plans of every floor level:
- Label use of each space, provide dimensions, ceiling height
- Show window and door location and sizes
- Indicate location of fire separations
- Show electrical lighting, control switches and outlets, interconnected smoke alarms, and when required, the location of battery powered emergency lighting units.
- Sections and Wall / Celing / Fire Separation Construction Details
- Construction Details of Egress Windows
- Details and construction notes / specifications
- Building elevations for coach house / garden home, including limiting distance calculations.
- Building elevations for exposing building face of existing house that is facing the coach house / garden home
Structural (may be incorporated into Architectural Plans)
- Footing / Foundation design
- Floor framing plan (including posts, beams, joists, lintels)
- Roof framing plan (including posts, beams, joists, lintels)
Mechanical (HVAC & Plumbing) Plans
- HVAC drawings
- Plumbing drawings (fixtures, water, drains, venting, riser diagrams)
Submit your application
All applications for building permits must be submitted using ePLAN. Paper applications are no longer accepted.
- Applicant creates a Customer Account with Markham’s ePLAN system.
- Once logged into ePLAN, Applicant requests a new application. A non-refundable Pre-Application Fee of $100 must be paid before drawings can be uploaded.
- Applicant uploads drawings directly to ePLAN.
- Markham staff conduct a Pre-Screen review to confirm the project complies with Markham’s Submission Standards.
- Once the submission passes the Pre-Screen Review, it becomes a permit application. The date of application is the date that Pre-Screen is approved.
Pay the fee
Building permit fees are estimated at the time of application. The estimate must be paid in full before plans review begins. During plans review the examiners will verify the fees. Any balance owing must be paid before the permit is issued.
- Group C Residential construction: $151
- Pre-Application Review: $100
Plans review and your permit
- All plans review and any required resubmissions are conducted electronically.
- You will receive an email notification when reviews have been completed.
- Log in to review mark-ups and comments.
- Resubmit revised plans and documents for further review (until approval).
- The City can’t process incomplete applications, and may abandon an application if it is inactive for 6 months or more.
- When the permit is issued, login to download the approved plans and documents.
- Applicants are responsible for printing the permit card, permit placard and one (1) set of approved plans for use on site.
Book your inspections
- All housing projects, including additions and renovations, require inspection.
- Book inspections through the Inspections Portal by selecting "Request a Building Inspection".
- Confirmation of a scheduled inspection will be emailed to the listed owner on the Building Permit.
Written from Markham’s own pages as published on 18 October 2026. The municipality decides what a permit needs: confirm with it before you apply. Legal notice