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Legal second units · Toronto & the GTA

Legal Basement & Second Units in Ontario

A basement unit is legal when the City says it is — not when it simply looks finished. USP builds legal second units across Toronto and the GTA, handling zoning, code compliance, permits and construction as one complete project.

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What makes a unit legal

What actually makes a basement unit legal

A legal second unit is a complete, self-contained home. It needs its own kitchen, its own bathroom, a sleeping area, and a way out that doesn’t depend on the rest of the house. On top of that, it has to satisfy three sets of rules at once:

The Ontario Building Code

Ceiling height, room sizes, egress windows, fire separation between the two units, interconnected smoke alarms, and permitted plumbing, electrical and ventilation.

The Ontario Fire Code

Smoke and carbon monoxide alarms where required, and ongoing fire-safety obligations once the unit is lived in.

Your municipal zoning by-law

Whether a second unit is allowed on your property, plus any parking and servicing requirements. This gets checked first — everything else depends on it.

The requirements that catch people out

Ceiling height

Many older GTA homes sit below the height a legal unit typically needs. Gaining it can mean underpinning.

Egress

Every bedroom needs a proper escape route. Small original basement windows usually have to be enlarged.

Fire separation

The two units must be separated to the required standard.

Moisture

Nothing gets built over a wet slab — drainage and waterproofing come first.

Every home is different. The exact code path depends on the age of your house and the scope of work, which is why we assess your specific property before committing to anything.

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Sets of rules every legal unit must satisfy
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Steps, from zoning check to handover
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Company, one contract, one point of contact
Our process

How we build your legal unit

One company, one contract, one point of contact — instead of juggling a designer, a permit consultant, a contractor and separate trades who each blame the others.

  • Zoning confirmation
    Before you spend anything on design.
  • Site assessment
    Ceiling height, moisture, drainage, windows, exits, existing services.
  • Design & permit drawings
    To Ontario Building Code requirements.
  • Permit application
    Submitted and managed through approval.
  • Construction
    All trades coordinated and supervised.
  • Inspections
    Booked and attended through to final sign-off.
  • Handover
    With your permit and inspection record in hand.

Questions about legal basement units

Request the permit and inspection history for your address from the City. A separate entrance, a separate hydro meter, or years of tenants prove nothing on their own — only the City’s record does.

Underpinning lowers the floor to gain height. It’s significant work, but it’s often what makes an otherwise impossible basement viable. We’ll tell you at the assessment whether it’s needed.

Yes — that’s the whole point of building it legally. Once it’s permitted and signed off, it’s a legitimate rental unit.