Loading...
Loading...
Detached ADU in Oshawa, Ontario: design, permit and build on a single contract. A typical 700 sq ft unit estimates at $275,000-$368,500 (about $393/sq ft), with $6,500-$11,500 including Durham Region charges in municipal approvals and a April-November construction season.

Free-standing backyard dwellings that are neither laneway nor garden-suite specific - a detached unit sized to whatever the lot and by-law allow.
Service area
Oshawa, Ontario
Durham Region
Typical build estimate
$275,000-$368,500
about $393/sq ft in Oshawa
Municipal approvals
$6,500-$11,500 including Durham Region charges
quoted separately from the build
Build season
April-November
134 cm snow · -4.1°C winter avg
Frost depth
1.2 m
footing depth, OBC Part 9
Local market
175,383
residents · walkability 50/100
Oshawa runs a residential rental housing licensing by-law covering the wards around Ontario Tech and Durham College, so in Windfields and Northglen a new secondary suite needs a licence as well as a permit. Owners planning student tenancy get the licensing test folded into the design brief, because it sets bedroom count and parking. Oshawa permits additional dwelling units and operates a rental-housing licensing regime in the university district that a new suite must satisfy.
Older large-lot neighbourhoods near downtown, plus student-rental territory around Ontario Tech and Durham College where licensing applies. Oshawa sees 134 cm of snow and -4.1°C winter averages. Ontario's 1.2 m frost-depth requirement governs every footing we pour for detached adu, and the April-November season sets the excavation window.
A detached unit stands clear of the main house, so it carries its own foundation, its own service laterals and its own exit - the three cost centres that separate it from an interior conversion on the same Oshawa lot. We trench services across the yard and pour to 1.2 m before the ground closes; framing, envelope and interior finishing then run through the cold months without holding up occupancy. Detached is the highest per-square-foot form of the four, and also the only one that leaves the existing house untouched - no shared walls, no disruption to the occupants during construction.
Everything you need to know about our services.
A typical 700 sq ft build in Oshawa estimates at $275,000-$368,500 - about $393/sq ft, set by $6,500-$11,500 including Durham Region charges in approvals, a 1.2 m frost-depth footing requirement and 134 cm of annual snow load. Final pricing follows the site visit.
Related service: Accessory Dwelling Units
Oshawa permits additional dwelling units and operates a rental-housing licensing regime in the university district that a new suite must satisfy. Approval costs in Oshawa run $6,500-$11,500 including Durham Region charges, quoted separately from construction so the permit stage holds no surprises.
Related service: Accessory Dwelling Units
Older large-lot neighbourhoods near downtown, plus student-rental territory around Ontario Tech and Durham College where licensing applies. At 50/100 walkability, Oshawa suites usually keep one parking space: enough to clear the zoning review without surrendering the whole yard. We work regularly in O'Neill, McLaughlin, Northglen.
Related service: Accessory Dwelling Units
A detached unit in Oshawa commands a higher rent and appraises closer to a standalone dwelling, because it has no shared entry and no shared mechanical. It also costs more per square foot: it needs a 1.2 m foundation and a roof engineered for 134 cm of snow that a basement conversion does not.
Related service: Basement Suites
Get a free, no-obligation quote from GTA ADU Builders - zoning review, permit drawings and construction for ADUs across the GTA.