Loading...
Loading...
Secondary Suites in King, Ontario: design, permit and build on a single contract. A typical 700 sq ft unit estimates at $91,500-$148,000 (about $385/sq ft), with $9,000-$16,500 including York Region and septic charges in municipal approvals and a May-October construction season.

Secondary suites carved out of an existing house - main-floor, upper-level or above-garage units built to the Ontario Building Code second-unit standard.
Service area
King, Ontario
York Region
Typical build estimate
$91,500-$148,000
about $385/sq ft in King
Municipal approvals
$9,000-$16,500 including York Region and septic charges
quoted separately from the build
Build season
May-October
150 cm snow · -5.3°C winter avg
Frost depth
1.2 m
footing depth, OBC Part 9
Local market
27,333
residents · walkability 21/100
King Township is almost entirely Oak Ridges Moraine and Greenbelt, with core-area designations that prohibit new building envelopes outright on some parcels. We run a moraine designation check against the property roll number before quoting a King City or Nobleton laneway-suite or garden-suite project, because on a core-area lot the honest answer is sometimes no. King Township permits additional dwelling units, with Oak Ridges Moraine and Greenbelt policies plus private servicing governing the majority of properties.
Estate and agricultural parcels, many over an acre, on private well and septic with moraine core-area restrictions. North-GTA snowfall of 150 cm and -5.3°C winters give King a May-October working season - foundations for secondary suites go in before the ground closes, with interior finishing carried through the cold months.
"Secondary suite" is the Ontario planning term for a second self-contained dwelling inside the existing house, so the review in King turns on the interior - separate kitchen and bath, an exit that does not pass through the primary unit, and rated separation between the two. Because the shell already exists, the schedule is driven by inspection sequencing rather than by weather: rough-in, framing and insulation inspections gate one another regardless of the May-October season. Bill 23 makes up to three units as-of-right on most serviced King lots, so a secondary suite generally proceeds by building permit alone without a rezoning application.
Everything you need to know about our services.
A typical 700 sq ft build in King estimates at $91,500-$148,000 - about $385/sq ft, set by $9,000-$16,500 including York Region and septic charges in approvals, a 1.2 m frost-depth footing requirement and 150 cm of annual snow load. Final pricing follows the site visit.
Related service: Our ADU services
King Township permits additional dwelling units, with Oak Ridges Moraine and Greenbelt policies plus private servicing governing the majority of properties. Approval costs in King run $9,000-$16,500 including York Region and septic charges, quoted separately from construction so the permit stage holds no surprises.
Related service: Our ADU services
Estate and agricultural parcels, many over an acre, on private well and septic with moraine core-area restrictions. King is car-oriented at 21/100 walkability, so parking retention and driveway access constrain the footprint more than the zoning envelope does. We work regularly in King City, Nobleton, Schomberg.
Related service: Our ADU services
Usually not. On a serviced King lot, Bill 23 permits up to three residential units as-of-right, so the path is a building permit rather than a six-to-twelve-month rezoning. King Township permits additional dwelling units, with Oak Ridges Moraine and Greenbelt policies plus private servicing governing the majority of properties.
Related service: ADU Building Permit
Get a free, no-obligation quote from GTA ADU Builders - zoning review, permit drawings and construction for ADUs across the GTA.