Legal Basement Apartments in Oakville & Burlington
Turn an unfinished basement into a legal, income-producing suite — designed, permitted, and built to the 2024 Ontario Building Code by a contractor who handles the whole process.
The short answer
A legal basement apartment in Oakville or Burlington typically costs $45,000–$60,000+, takes 3–6 weeks to build once permits are issued, and must be a permitted, inspected secondary suite under the 2024 Ontario Building Code. 707 Reno handles design, permit drawings, submission, and construction end to end.
Looking to just remodel your basement for personal use — no legal apartment? See our basement finishing page →
01What does a legal basement apartment cost?
Most legal basement suites in the Oakville and Burlington area land between $45,000 and $60,000 or more. Where a specific project falls depends on the size of the space, the condition of the existing basement, how much plumbing and electrical has to be added, whether an egress window needs to be cut and a window well dug, and the level of finishes you choose.
| What drives the price | Why it matters |
|---|---|
| Plumbing for a new kitchen & bath | Adding a wet zone where there was none is one of the biggest cost levers |
| Egress window & window well | Cutting the foundation and excavating for a code-compliant escape window |
| Existing basement condition | A dry, framed basement costs less than a bare, damp, or low-ceiling one |
| Electrical & ESA approval | New circuits, panel capacity, and inspection sign-off |
| Finishes & layout | Flooring, cabinetry, tile, and how many rooms the suite contains |
A free in-person assessment is the only way to get a real number for your specific basement — these ranges are a starting point, not a quote.
02What makes a basement legal in Ontario?
A legal basement apartment is called a secondary suite under the 2024 Ontario Building Code, which has been in force since January 1, 2025. A suite is only legal once it has been permitted, inspected, and approved — building it first and trying to legalize it later is the most expensive mistake homeowners make, and it can mean tearing out finished walls. Here’s what the code requires:
- Self-contained unitIts own kitchen, bathroom, and sleeping and living space, separate from the main home.
- Ceiling heightMinimum 1.95 m (about 6’4¾”) over the required floor area, including the path to the exit.
- Emergency egressA compliant escape window or door from the bedroom, sized to the code’s minimum clear opening.
- Smoke & CO alarmsInterconnected across the whole building so any alarm triggers all of them. The 2024 code now allows wireless interconnection — a real cost saver in existing homes.
- Separation between unitsUnder the 2024 code, the default requirement is a continuous smoke-tight barrier between the suite and the main dwelling, with the exact assembly confirmed per project and inspector.
- Independent heatingThe suite must be able to control its own temperature — a zoned system, mini-split, or baseboards all qualify.
- VentilationKitchen and bathroom exhaust vented to the outside, plus adequate fresh-air supply.
- Electrical & ESAAll wiring inspected and approved by the Electrical Safety Authority.
Zoning, parking, and registration rules also apply and vary by municipality — Oakville, Burlington, Milton, and Halton Hills each have their own layer. We confirm these up front so there are no surprises at permit review.
03How the process works
Free assessment
We walk your basement, talk through your goals (rental income, in-law suite, resale), and tell you honestly whether it’s a good candidate and roughly what it’ll cost.
Design & permit drawings
We produce the floor plans and drawings the city needs and lay out a compliant suite that fits your space.
Permit submission
We submit the application and drawings to your municipality and manage the back-and-forth with the building department.
Construction
Framing, plumbing, electrical, HVAC, fire/sound separation, and finishes — typically 3–6 weeks on site.
Inspections & sign-off
We coordinate the required inspections through to final approval, so you end up with a documented, legal suite.
04Frequently asked questions
How much does a legal basement apartment cost in Oakville or Burlington?
Do I need a building permit?
How long does construction take?
What ceiling height do I need?
Is the work guaranteed?
What if I just want to finish my basement, not turn it into a legal apartment?
Find out if your basement qualifies
Book a free, no-pressure assessment. We’ll tell you straight whether your basement is a good candidate, what it would cost, and what the suite could rent for.
707 Reno Design & Build is a licensed and insured residential renovation contractor serving Oakville, Burlington, Milton, and Halton Hills, Ontario. Code requirements summarized here reflect the 2024 Ontario Building Code and are provided for general guidance; final requirements are confirmed per project with your local building department. Workmanship backed by a 3-year warranty.