Does my property qualify for a second suite?
Most serviced urban lots in Ontario can have a second unit. Whether yours can comes down to two things: the house and the lot. Check both yourself in a few minutes, then get a written answer before you pay for drawings.
Seven questions. Yes, no or not sure.
- 01Is the finished ceiling at least 1.95 m (6′5″)?
- 02Does every bedroom have a window you can climb out of, or a door outside?
- 03Can the suite have its own way in, without crossing the main home?
- 04Is the lot on municipal water and sewer?
- 05Is the property clear of floodplain, conservation and heritage flags?
- 06Could you fit one more parking space if asked?
- 07Is there a clear side path to where the entrance would be?
Start with what you know.
Answer yes, no or not sure. There are no wrong answers.
- Ceiling heightOpen
- Escape windowOpen
- Own way inOpen
- Water and sewerOpen
- Flood, conservation, heritageOpen
- ParkingOpen
- Side pathOpen
A self-check, not a zoning decision. Rules vary by municipality.
The province opened the door.
Ontario lets most serviced urban lots with a detached, semi-detached or row house have up to 3 units, and municipalities can’t ask for more than 1 parking space per added unit. That sets the floor, not the full answer. Two sets of rules decide the rest.
The Building Code
Ceiling height, a way out, fire separation and alarms. It decides whether the house can take a unit.
Zoning
Size, height, setbacks, parking, entrances and servicing. It decides whether the lot can.
House check: the Building Code.
These come from the Ontario Building Code, so they apply wherever you are. We check your design against the official Code text.
- 01
Ceiling height
Clear height in the finished suite.
What the Code asks for1.95 m (6′5″), with 1.85 m (6′1″) allowed under beams and ducts.
- 02
Escape window
On every floor with a bedroom: a window you can climb out of, or a door straight outside.
What the Code asks forOpens from inside without tools. A clear opening of 0.35 m², no side under 380 mm, and 550 mm clear in a window well.
- 03
Fire separation
A barrier that keeps a fire in one unit from spreading into the other.
What the Code asks forA rated wall and ceiling assembly, or a continuous smoke-tight barrier of 15.9 mm Type X drywall.
- 04
Smoke alarms
Alarms in both units and in any shared space.
What the Code asks forInterconnected so they all sound together, hard-wired or wireless.
More on the basement side: Basement ADU requirements.
Lot check: your municipality.
These vary by municipality. The ranges are what we found across the building departments we work with. Yours may differ.
- 01
Water and sewer
Whether the lot is on full municipal services.
What we foundSome municipalities don’t allow a unit on a well or septic system. Others allow it with proof of capacity.
- 02
Flood, conservation and heritage
Flags on the property that add an approval or rule a unit out.
What we foundSeveral municipalities bar units on floodplain lands. A conservation authority permit or heritage approval may come first.
- 03
Parking
Room for one more space, if your municipality asks for it.
What we foundFrom none to 1 space per added unit. Ontario doesn’t let municipalities ask for more.
- 04
Entrance and path
A clear route from the street to the suite’s door.
What we foundWhere a path is required, 0.9 m to 1.1 m wide with about 2.1 m of headroom. Some allow only one door on the front of the house.
- 05
Garden suite fit
For a backyard unit: distance from the lot lines, size and height.
What we foundSetbacks from 0.6 m to 1.2 m and height limits from 4.0 m to 6.5 m. Size caps vary.
For the yard side, see Garden Suite ADU requirements.
Already have a second unit? Check its age.
If the house already had two units on July 14, 1994, the Ontario Fire Code’s retrofit rules for two-unit houses apply to it. A unit created after that follows the Building Code. Either way, it needs to be legal before you rely on it.
A written answer, before drawings.
Our feasibility check is a fixed fee (see Pricing), credited in full toward your drawings if you go ahead with us. It’s prepared by a BCIN-qualified designer, and the result is yours to keep, whoever you hire next.
An address and photos
A survey if you have one, and a few photos of the space or the yard. For an existing suite, any permits or inspection reports.
Zoning, lot and servicing
Unit count, size, height, setbacks, parking, entrance and path, flood and conservation flags, and which building department reviews it.
A plain written answer
What your lot allows and the likely permit path, citing the by-law sections we relied on.
Lot questions.
Can I have 3 units on my lot?
Ontario lets most serviced urban residential lots have up to 3 units, but each municipality sets the details, and some allow more or add conditions. Check what your lot allows. Our design work covers a house with a second suite.
What if my lot does not qualify?
Then you find out before you spend money on full drawings. If the rules don’t allow the unit you had in mind, we tell you why and whether another type could fit, such as a basement apartment instead of a garden suite.
Does the check cover rural lots on a well and septic?
Yes, we flag servicing questions. Some municipalities don’t allow additional units on a well, cistern or septic system, and others allow them with proof of capacity. We don’t offer septic design, but we tell you early if your lot needs it.
How much parking will I need?
No more than 1 space per additional unit, because Ontario doesn’t let municipalities require more. Some require none for the first unit, and some areas require none at all.
Pick the question closest to yours.
We’ll tell you what your lot allows.
Send the address and a few photos. You get a written answer, citing the rules, before you spend anything on drawings.