Basements, Additions & Outdoor · Oshawa
Legal Basement Apartments in Oshawa
Secondary suites built to the Ontario Building Code and Fire Code, with the permit, egress and fire separation done properly.
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Oshawa, Durham Region
Legal Basement Apartments in Oshawa
Demand for legal basement apartments in Oshawa is strong, whether for rental income, a parent moving closer or a young adult who wants their own space. Many post-war bungalows, older downtown homes and newer north-end subdivisions in Downtown Oshawa, Lakeview and Eastdale have basements well suited to a secondary suite.
Secondary suites in Oshawa are approved by the City of Oshawa, which sets its own zoning, parking and entrance rules on top of the Ontario Building Code and Fire Code. We check what your lot allows, coordinate drawings and the permit, then build the suite and book inspections through to final sign-off.
We also bring existing Oshawa basement units up to code: assessing fire separation, exits, ceiling height and alarms, and doing the permit and work needed to make the suite legal.
Call (647) 424-1511 or send the form on this page for a free basement apartment quote in Oshawa. Tell us what you want to change, add a few photos of the space, and we will book a visit and send a written quote that lists the scope, the materials, the permits involved and the schedule.
Oshawa homes
What legal basement apartments involves in Oshawa's houses
Century and heritage homes in Oshawa
Older Oshawa homes can take a legal basement apartment, but the work is heavier: low ceilings may need underpinning, stone foundations need careful moisture work, and fire separation has to be built continuously through irregular framing. A second exit and egress windows are often the deciding factors.
Post-war bungalows and back-splits in Oshawa
Oshawa's post-war bungalows are among the best houses for a basement apartment. The side door at grade often gives the suite its own entrance, the footprint gives room for a kitchen, bathroom and one or two bedrooms, and the Building Code includes some allowances for houses that have stood for years.
Newer homes built since 2000 in Oshawa
Newer Oshawa homes with a roughed-in basement bathroom and good ceiling height are strong candidates for a suite. Where the builder offered a separate side entrance it saves significant work. Engineered floor joists above need a fire separation designed for that type of floor.
Rules in Oshawa
Permits and approvals for legal basement apartments in Oshawa
Building permits
Building permits in Oshawa are issued by the City of Oshawa. Electrical work anywhere in Ontario is done by a licensed electrical contractor under an Electrical Safety Authority (ESA) permit. We confirm what your project needs before you sign and book every inspection.
Additional residential units
Since the province's More Homes Built Faster Act (2022), most urban serviced lots in Ontario with a detached house, semi or townhouse can have up to three units: the main home plus two additional units, one of which may be in a separate building. Municipalities still set zoning details, and the province limits how much parking they can require. The City of Oshawa applies these rules locally, and every unit needs a building permit and must meet the Building Code and Fire Code.
Testing before demolition
Homes built before the 1990s can contain asbestos in plaster, textured ceilings, floor tile, vermiculite insulation and pipe wrap, and homes from before the 1960s often have lead paint. In Oshawa's older houses we test suspect materials before demolition and handle them by the regulations if they are found.
The service
Legal Basement Apartments, Built to Code
A legal basement apartment, also called a secondary suite or additional residential unit, can bring in rental income, house a family member or help an adult child stay close to home. Ontario's rules now allow additional units in many houses, but a suite is only legal when it is built under a building permit and meets the Ontario Building Code and Fire Code.
The details that make a suite legal are the same ones that make it safe: fire separation between the units, smoke and carbon monoxide alarms, a proper exit and egress windows from bedrooms, adequate ceiling height, separate heating considerations, and the right electrical and plumbing. Zoning, parking and entrance requirements vary from one municipality to the next.
More about legal basement apartments →The process
How your Oshawa project comes together
01
Consultation
Tell us what you want to change and send a few photos. We visit, measure and talk through options.
02
Written Quote
A clear scope, materials, permits and schedule, in writing. No vague allowances.
03
Permits & Planning
Drawings, permits and material orders lined up before demolition starts.
04
Build & Walk-Through
Work done in the right order, inspected where required, and walked through with you at the end.
Across Oshawa
Legal Basement Apartments throughout Oshawa
Oshawa has older homes around downtown and the original auto-plant neighbourhoods, post-war bungalows across the south and east, and newer subdivisions in Windfields, Taunton and Northglen near Durham College and Ontario Tech University.
Questions
Legal Basement Apartments in Oshawa: FAQs
How do I get a legal basement apartments quote in Oshawa?+
Call (647) 424-1511, use the form on this page or email info@ontariorenovationcompany.com. Tell us what you want to change and send a few photos, and we will book a visit and send a written quote for your Oshawa project.
What kinds of Oshawa homes do you work on?+
All of them. Housing in Oshawa includes century and heritage homes, post-war bungalows and back-splits and newer homes built since 2000, and each comes with its own considerations, from older wiring and foundations to builder warranties, septic systems and shoreline rules. We plan the work around the house you actually have.
Can I legally put an apartment in my basement?+
In many Ontario municipalities, yes. Provincial rules allow additional residential units in many houses, but zoning, lot, parking and entrance rules vary locally, and every unit needs a building permit. We check what your property allows before you commit.
What makes a basement apartment legal?+
It must be built under a building permit and pass inspection, meeting the Ontario Building Code and Fire Code for fire separation, exits, egress windows, ceiling height, alarms, electrical and plumbing.
Does a basement apartment need a separate entrance?+
Often, though requirements depend on the municipality and the layout. A side or rear entrance with a properly built stairwell is a common part of our suite projects.
Can you legalize an existing basement apartment?+
Often, yes. We assess the existing suite against the code, list what needs to change, such as fire separation, alarms, egress or ceiling height, and handle the permit and work to bring it into compliance.
Do you offer legal basement apartments across Oshawa?+
Yes. We work throughout Oshawa, including Downtown Oshawa, Lakeview, Eastdale, McLaughlin, Northglen, Taunton and Windfields, and in nearby Courtice, Ajax, Bowmanville, Pickering and Newcastle.
More renovation services in Oshawa
Alongside legal basement apartments, we also handle garden suites and detached ADUs, basement finishing and bathroom renovations in Oshawa, so related work can be planned together.
Other basements, additions & outdoor services in Oshawa: basement finishing, garden suites & detached adus, home additions and decks & outdoor living.
Further reading
Your Oshawa renovation, done properly.
Tell us what you want to change and send a few photos. We will book a visit and send a clear written quote, with no obligation.