Ontario Design Studio prepares BCIN-certified permit drawings for secondary suites, garden suites, and accessory dwelling units (ADUs) across Ontario. Since Ontario's 2023 provincial housing policy changes, secondary suites are now permitted province-wide on residential lots - creating opportunities for homeowners to add rental income, accommodate family, or increase property value.
Types of Secondary Suites We Draw
- Garden suites - standalone backyard homes (also called granny flats or backyard houses)
- Coach houses and carriage houses - living space above detached garages
- Laneway housing - in Toronto and eligible municipalities
- Garage conversions - converting existing garage to legal living space with full OBC compliance
- Above-garage secondary suites - self-contained units with separate entrance
- Detached accessory dwelling units (ADUs) - new construction on existing residential lots
- Basement secondary suites - configured as a separate dwelling unit below grade
- Prefab and modular secondary suite permit applications
Ready to start your project?
Ontario Design Studio delivers BCIN-certified, OBC-compliant building permit drawings across Ontario and the GTA. Call 416-558-9607 or request your free quote.
Drawing Package Includes
Our secondary suite drawing package includes: site plan showing suite location, all setbacks, and lot coverage calculation; floor plans with room dimensions, egress window compliance, and accessibility notes; exterior elevations; foundation plan; cross-sections; energy compliance form SB-10; zoning summary; and Schedule 1 designer information.
Key Considerations for Ontario Secondary Suites
- Province-wide permission as of 2023: Up to three units per lot (main house + two additional units) in most residential zones
- Garden suite setbacks vary by municipality: Each city has different minimum setback requirements from property lines
- Utility connections require planning: Water, sewer, hydro, and gas connections for detached suites need coordination with local utilities
- Parking requirements may be reduced: Under Ontario's housing policy changes, parking requirements for additional units have been relaxed in many municipalities
Secondary Suite Permits by City
Related Resources
- Ontario Building Code 2024 Changes - New Multiplex and Secondary Suite Rules
- Building Permit Drawing Cost Ontario 2026
- How the Ontario Permit Process Works
Frequently Asked Questions
What types of secondary suites are allowed in Ontario?
Since Ontario's 2023 housing policy changes, secondary suites are permitted province-wide on residential lots. Types include basement apartments, garden suites (backyard homes), coach houses over garages, laneway houses, garage conversions, and above-garage units.
Do I need a building permit for a garden suite in Ontario?
Yes. A garden suite or any secondary dwelling unit requires a building permit in Ontario. You'll need BCIN-certified drawings showing the suite's floor plan, elevations, foundation, setbacks, and OBC compliance including fire safety and energy efficiency.