How much does legal basement apartment cost in King City?

With Zigma Group, legal basement apartment starts from $72,000, and most projects fall between $72,000 and $125,000. Prices are in Canadian dollars before HST, as of October 2026, and are confirmed after a site visit. The main factors are whether a new separate entrance has to be built; fire separation and egress window work; and kitchen and bathroom finish level.

What makes a basement apartment legal in Ontario?

It is permitted by local zoning, built under a building permit, meets Ontario Building Code requirements for fire separation, exits, ceiling height and ventilation, passes inspection, and is registered where the municipality requires it.

Can my existing basement apartment be legalised?

Often, yes. We compare it with the current requirements, prepare drawings, apply for the permit and carry out the corrections, which commonly involve fire separation, egress and electrical work.

Do you do legal basement apartment projects in King City?

Yes. We work throughout King City, including King City, Nobleton and Schomberg. Call +1 (647) 718-3913 to arrange a visit.

Who issues the permit for this work in King City?

Where a permit is needed, it is issued by the Township of King's building division. We prepare the drawings and handle the application and inspections.

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Legal Basement Apartment

Basements · King City

Legal Basement Apartment in King City

A legal second suite turns a basement into a self-contained rental or family apartment. The difference between legal and not is the permit, the fire safety and the inspections. In King City, the township is mostly estate homes and rural properties on large lots.

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Compact new bathroom with a floating vanity and slate-grey floor tile — From our Cobblestone Drive renovation

Scope

What is included.

Feasibility check against zoning and the Building Code
Permit drawings and application
Fire separation and interconnected smoke alarms
Separate entrance and egress windows
Kitchen, bathroom and laundry
Electrical, heating and ventilation for a second unit

Cost

What it costs.

From $72,000

Most projects in King City: $72,000 to $125,000

What moves the price

Whether a new separate entrance has to be built
Fire separation and egress window work
Kitchen and bathroom finish level

Prices are in Canadian dollars before HST, as of October 2026. Every project is confirmed with a written quote after a site visit.

Local knowledge

Legal Basement Apartment in King City.

Homes like these
Walk-out basements are common on sloped rural lots, and extra bathrooms must be checked against the septic system.
Housing
In King City, the township is mostly estate homes and rural properties on large lots.
Permits
Building permits in King City are issued by the Township of King's building division. We prepare the drawings, submit the application and book the inspections.
Areas we cover
We work throughout King City, including King City, Nobleton and Schomberg.
Rural services
Many King properties rely on a well and a septic system. Adding bedrooms or bathrooms can require the septic system to be reviewed or upgraded.
Greenbelt and Moraine
Most of the township is covered by the Greenbelt and Oak Ridges Moraine plans, which limit where and how much you can build.

Before you start

What to know.

The rules
Ontario now allows additional residential units on most urban residential lots, but each municipality sets its own registration and zoning details. A second suite must meet the Ontario Building Code and be built under a permit.
What inspectors look for
Fire separation between units, a safe exit, ceiling height, window size, smoke and carbon monoxide alarms, and properly inspected electrical work.
Existing unpermitted suites
An older basement apartment built without a permit can often be legalised. We assess what has to be opened up and corrected.

How we work

One team for every stage.

AssessWe survey the house as it stands.
Design and permitsDrawings and approvals before work starts.
Strip-outWhat is worn out comes off.
RebuildStructure, wiring, plumbing and walls.
FinishesCabinetry, tile, floors and paint.
HandoverWalkthrough and documents.

Questions

Legal Basement Apartment in King City: the short answers.

How much does legal basement apartment cost in King City?: With Zigma Group, legal basement apartment starts from $72,000, and most projects fall between $72,000 and $125,000. Prices are in Canadian dollars before HST, as of October 2026, and are confirmed after a site visit. The main factors are whether a new separate entrance has to be built; fire separation and egress window work; and kitchen and bathroom finish level.
What makes a basement apartment legal in Ontario?: It is permitted by local zoning, built under a building permit, meets Ontario Building Code requirements for fire separation, exits, ceiling height and ventilation, passes inspection, and is registered where the municipality requires it.
Can my existing basement apartment be legalised?: Often, yes. We compare it with the current requirements, prepare drawings, apply for the permit and carry out the corrections, which commonly involve fire separation, egress and electrical work.
Do you do legal basement apartment projects in King City?: Yes. We work throughout King City, including King City, Nobleton and Schomberg. Call +1 (647) 718-3913 to arrange a visit.
Who issues the permit for this work in King City?: Where a permit is needed, it is issued by the Township of King's building division. We prepare the drawings and handle the application and inspections.