Short answer: Yes, you can build a garden suite in Vaughan, and it needs a building permit. Vaughan amended both of its zoning by-laws in March 2025, through By-law 082-2025 and By-law 083-2025. Under both, one backyard unit is allowed per lot. It must be at least 4.0 metres from the house and no larger than the main home.
Key takeaways
| Question | Short answer | Source |
|---|---|---|
| Permit needed? | Yes. Detached structures of 10 m² or more, or any size with plumbing | City of Vaughan |
| Which by-law | Usually both 1-88 and 001-2021 while 001-2021 is under appeal | City of Vaughan — Zoning |
| How many units | Up to two additional units; at most one in a detached accessory building | By-law 083-2025 s. 5.21 |
| Distance from the house | At least 4.0 m from the principal building | 082-2025; 083-2025 |
| Size and coverage | Floor area no more than the main home's; lot coverage 45% or the zone maximum, whichever is greater | 083-2025 s. 5.21.6 and 5.21.8 |
| Access | Separate entrance; 1.2 m hard-surfaced walkway from the street, or a driveway | 083-2025 s. 5.21.7 |
Two zoning by-laws
Vaughan's Zoning Services page says Comprehensive Zoning By-law 001-2021 is under appeal to the Ontario Land Tribunal, so By-law 1-88, as amended, remains in effect across the city. Building applications not considered transitioned under Section 1.6 of 001-2021 must comply with both. In practice, a garden suite design has to pass two sets of standards at once, and the stricter number in each category governs. Council passed matching additional unit amendments to both by-laws on March 25, 2025: 082-2025 for 1-88 and 083-2025 for 001-2021. Get written zoning confirmation from Zoning Services before design.
The 2025 additional unit rules
- Servicing: additional units are allowed only on lots with municipal water and sanitary services.
- Unit count: two additional units inside a single detached, semi-detached or townhouse dwelling, or one inside plus one in a residential accessory structure.
- Separation: the building with the unit must be at least 4.0 m from the principal building.
- Floor area: no more than the gross floor area of the principal dwelling unit.
- Lot coverage: 45% or the zone maximum, whichever is greater, on a residential lot with an additional unit.
- Entrance: separate from the main entrance, on a side or rear wall or through a common vestibule. It must be reached by a 1.2 m hard-surfaced walkway from the street, or from a driveway, and a new entrance cannot share the main entrance's wall. Under 1-88 the entrance is also set back at least 1.2 m from the interior side lot line, unless the zone requires more.
- Parking: the main home's rate plus one space per additional unit, except inside a Protected Major Transit Station Area.
- Not allowed: in a building with a bed and breakfast or home occupation use. Vaughan's ADU page also excludes the Woodbridge Special Policy Area and floodplains.
Height and lot-line setbacks for the backyard building still come from your zone, so we confirm them on the survey. For build options and our approach to a Vaughan lot, see garden suites in Vaughan. New to the idea? Start with what a garden suite is. Province-wide rules are covered in additional residential units in Ontario, and you can compare Vaughan with nearby cities in the GTA garden suite rules comparison.
Building permit checklist
Vaughan's accessory structures permit page asks for:
- A PDF construction drawing set that is fully dimensioned, signed and dated.
- A property survey or site plan showing the structure and its distance to each lot line.
- A lot grading permit issued by Vaughan's Development Engineering department.
- Foundation, floor or framing plans, elevations showing height and openings, wall sections, and a roof plan with truss drawings where they apply.
- The qualified designer's name, BCIN registration number, signature and responsibility statement. Owners may also prepare their own drawings.
- Plumbing permit requirements, plus TRCA or Urban Design and Cultural Heritage approval where they apply.
Vaughan also requires renovators and contractors to hold a City of Vaughan business licence. The ADU page notes that the water distribution piping may need an upgrade under Ontario Building Code Division B, 7.6.3.1. Start with our free feasibility check.
Other approvals and charges
If a design cannot meet the by-laws, the fallback is a minor variance at Vaughan's Committee of Adjustment, which adds a hearing to the schedule. Designing to comply avoids that step. Ontario's Development Charges Act (s. 2(3.2) and (3.3)) generally exempts one residential unit in an ancillary building; confirm with the City. For cost context, see garden suite cost in Ontario. For the build method, see modular vs site-built. Nearby: Markham, the Markham permit guide, the Mississauga permit guide, the Toronto permit guide, the Brampton permit guide and the Oakville permit guide.
FAQs
Sources
- City of Vaughan — By-law 083-2025 (amends 001-2021, additional residential units)
- City of Vaughan — By-law 082-2025 (amends 1-88, additional residential units)
- City of Vaughan — Zoning Services
- City of Vaughan — Accessory structures building permits
- City of Vaughan — How to get a secondary suite / ADU
- Development Charges Act, 1997
Disclaimer: Figures cited are market estimates provided for information only and are not a quote. Municipal rules, fees, and programs change — always verify current requirements with your local authority. Modular X provides exact pricing only after a site-specific feasibility review.