Legal Basement Apartment
in Uxbridge
Uxbridge has rules that catch investors off guard — stricter parking than the rest of Durham, and conservation limits on much of its rural land. Here's exactly what the Township and the Ontario Building Code require for a legal basement apartment, and how Cornerstone gets it permitted, inspected, and registered without surprises.
The Two Rule Books
What Makes a Basement Apartment "Legal" in Uxbridge
In Uxbridge a second suite is an Additional Residential Unit (ARU). To be legal it has to satisfy both the Township's zoning and registration rules (parking, landscaping, registration) and the Ontario Building Code (room sizes, ceiling height, fire separation and safe exits). Uxbridge's rural setting means a couple of its rules are stricter than the rest of Durham — which is exactly why local knowledge matters here.
Uxbridge Zoning & Registration
Sets the outside rules: parking, landscaping and a mandatory registration — under Zoning By-law 81-19 (as amended for Additional Residential Units) and Registration By-law 99-107.
Ontario Building Code
Sets the inside rules: minimum room sizes, ceiling height, egress windows, a 30-minute fire separation and interconnected alarms.
Uxbridge Requires TWO Parking Spaces
Unlike most of Durham Region — where a second unit needs just one space — Uxbridge requires a minimum of two parking spaces dedicated to the second unit, located outside of a garage, in addition to the spaces for the main home. It's a rural-municipality rule, and it's the single most common thing that trips up investors who plan a suite around a one-space assumption. We confirm your lot can actually fit it before you commit to a property or a design.
Check If Your Lot QualifiesRural Lots: Read This First
Two Extra Hurdles Outside the Urban Boundary
Much of Uxbridge is rural, and rural lots face two checks a subdivision lot doesn't. Both have to clear before a permit can be issued — so they're worth confirming before you buy.
Conservation Land Can Limit or Block a Suite
- Large parts of rural Uxbridge fall under the Oak Ridges Moraine Conservation Plan or the Greenbelt Plan. Within these plans, land carries a designation — Natural Core, Natural Linkage, Countryside or Settlement — and the rules for what you can build get more restrictive the closer you are to the protected natural-heritage areas.
- Depending on that designation, a second unit may be limited, or not permitted at all — the protected core and linkage areas are the most restricted. It's not something you can assume from the lot size; it comes down to where the property sits on the conservation map.
- Properties near a Lake Simcoe (LSRCA) or Central Lake Ontario (CLOCA) conservation-authority regulated area may also need that authority's written clearance before the Township can issue a permit.
- This is the first thing to confirm on a rural lot — we check your property's designation against the public mapping before you commit to a property or a design.
Check it yourself in two minutes: Ontario's public GeoHub Oak Ridges Moraine land-use map and the Region's yourDurham viewer both let you search an address and see its designation. They're a great first screen — but the final word is always the Township's Zoning By-law 81-19, which we confirm directly with Planning before any design work.
The Oak Ridges Moraine (green) runs through the middle of Uxbridge. This shows the Moraine boundary only — not the Natural Core, Linkage or Countryside designations that determine what you can build, which we confirm on your specific lot. Source: Province of Ontario.
Septic Capacity (Homes Not on Municipal Sewer)
- If your home is on a private septic system, adding a suite increases the home's design sewage flow — and the Ontario Building Code requires the system to have capacity for the added load before a permit is issued.
- A higher bedroom count raises the required daily flow, and an older or standard-sized tank and leaching bed can come up short. Where it does, a septic upgrade gets built into the scope — better to know up front than after closing.
- We coordinate the septic evaluation and any Durham Region Health review as part of the project, so the wastewater side is confirmed early — not discovered after you've bought.
Rule Book 1
Uxbridge Zoning Requirements
These are the property-level rules an Uxbridge home must satisfy to add a legal Additional Residential Unit.
Parking — Two Exterior Spaces
- Minimum two parking spaces must be provided for the second unit, in addition to the parking for the main residence.By-law 81-19, ARU provisions
- Those two spaces must be outside of a garage — in a driveway or legal exterior parking area. You can't count garage storage toward the tenant's required spaces.
- This is stricter than other Durham municipalities (most require one), reflecting Uxbridge's rural servicing and transit context. It's the rule to confirm before buying a property for a suite.
The Driveway & Landscaping Limit
- Because you need two exterior spaces, the instinct is to widen the driveway — but Uxbridge limits that. Driveway alterations are restricted if they violate your zone's maximum permitted driveway width or drop your property below the mandatory soft-landscaping minimums.By-law 81-19
- This is the balancing act on most Uxbridge lots: fitting two legal spaces without breaching the coverage rules. It's exactly the layout problem we solve before drawing plans.
Entrance Access
- An unobstructed access path must be maintained to the secondary unit's private entrance, compliant with standard neighbourhood side-yard setback parameters.
- We design the entrance and access path into the plan so emergency egress and code clearances are covered from day one.
Rule Book 2
Ontario Building Code: Inside the Suite
An Uxbridge building inspector verifies every measurement against the Ontario Building Code before granting final occupancy. These numbers apply Province-wide, in Uxbridge the same as anywhere in Ontario.
Minimum Room Sizes
| Room | Minimum Floor Area |
|---|---|
| Living Room | 13.5 m² (145 ft²)May reduce to 11 m² if combined with other space in a one-bedroom unit. |
| Kitchen | 4.2 m² (45 ft²)May reduce to 3.7 m² in a one-bedroom unit. |
| Combined Living/Dining/Kitchen (1-Bdrm) | 11 m² (118 ft²) minimum unobstructed. |
| Primary Bedroom | 9.8 m² without a closet, or 8.8 m² with a built-in closet. |
| Additional Bedrooms | 7.0 m² without a closet, or 6.0 m² with a closet. |
| Bathroom | Self-contained — toilet, sink and tub/shower with proper clearance. |
Egress Windows
- Every bedroom needs an egress window with a minimum unobstructed opening of 0.35 m², with no single dimension less than 380 mm.OBC 9.9.10.1.(1)(b)
- Where that window opens into a below-grade window well, the Code requires a clearance of at least 550 mm in front. We often build deeper than the minimum so an outward-swinging sash never blocks the escape path.OBC 9.9.10.1.(5)
Ceiling Height
- The finished ceiling must be at least 1.95 m (6 ft 5 in) across the habitable space.OBC 9.5.3.1
- It may drop to 1.85 m (6 ft 1 in) only under localized obstructions — beams, structural columns or boxed ductwork. Where the open floor is below 1.95 m, the floor may need lowering (underpinning or bench footing) to pass.
Fire Separation & Alarms
- The floor/ceiling and walls separating the suite from the main home must form a continuous, smoke-tight fire separation with a minimum 30-minute fire-resistance rating. A typical way we achieve this is mineral wool packed in the joist cavities with two continuous layers of 5/8" Type X drywall on resilient channels — one tested method that meets the requirement.OBC 9.10.9.14
- Smoke alarms are required on every storey of both units and must be fully interconnected — if one sounds in the basement, every alarm in the house above sounds at the same time. Carbon monoxide alarms are required as well.OBC 9.10.19
Permit & Registration
How a Legal Suite Gets Approved in Uxbridge
Building the suite to code is only half of it. Under Registration By-law 99-107, the unit must be registered with the Township — and it's an offence to advertise or occupy a suite without an active registration.
Confirm Your Property
We check your zone and conservation designation, confirm the two-space parking can actually fit, and check the landscaping limits before committing to a layout.
Design & Drawings
Scaled drawings showing existing and proposed floor plans, room areas, egress, fire separation and alarm locations — prepared to the Township's submission standards.
Building Permit
A building permit is required for the second unit and submitted to the Township of Uxbridge. On conservation land, written clearance may be needed before the permit can be issued.
Multi-Agency Inspection
Under By-law 99-107, registration requires a multi-agency review — Zoning, Building, Fire Code and Property Standards all sign off.
Registered on the Public Register
Once inspections clear, the two-unit house is entered on the Township's public register — your proof of a legal, registered suite, which protects insurance and resale.
It's an offence to advertise or occupy a suite without registration. By-law 99-107 requires every two-unit house to be registered, and an unregistered suite carries fines, insurance and liability risk. Built and registered properly, it's a clean, legal income unit.
Why Build It Legal
A Registered Suite Is Worth More
Real Rental Income
A legal, inspected suite can be rented with confidence — and in a commuter town like Uxbridge, a second unit can carry a real chunk of your mortgage. It needs its own full bathroom built to the Uxbridge standard, waterproofed and inspected like the rest of the suite.
Insurance & Resale
A registered suite is what your insurer and a future buyer want to see. An undisclosed unit can void coverage and scare off buyers.
Tenant Safety
Code-built fire separation, egress windows and interconnected alarms keep the people living there safe — and keep you out of liability.
No Surprises Later
Confirming the two-space rule, conservation status and coverage limits up front means no rejected plans, no forced rework, and no order to vacate down the road.
Common Questions
Uxbridge Basement Apartment FAQ
Why does Uxbridge need two parking spaces when other towns need one?
I'm on a rural lot near the Oak Ridges Moraine — can I still build a suite?
I'm on a septic system — does that affect adding a suite?
Can I just widen my driveway to fit the two spaces?
Does the suite have to be registered?
My basement ceiling feels low — is that a dealbreaker?
What affects the cost of a legal basement apartment?
Thinking About a Legal Basement Apartment in Uxbridge?
Start with a basement diagnostic. We'll confirm the two-space parking fits your lot, check your conservation designation and septic capacity, measure your ceiling and egress, and map out the path to a legal, registered suite — built once, built right.
