The short answer
Most basements we finish in Durham Region fall between $27,000 and $90,000 or more, depending on size, finishes and whether it’s a personal space or a legal rental unit. A standard finished basement typically takes 3 to 4 weeks; a full legal apartment takes closer to 2 months.
Basement finishing price ranges in Durham
| Scope | Typical range | What it usually includes |
|---|---|---|
| Basic finished basement | Starting around $27,000 | Framing, insulation, drywall, flooring, lighting, paint, one open space |
| Basement with bathroom and extras | Mid to upper part of the $27,000 to $90,000+ range | Bedrooms, a full bathroom, wet bar or kitchenette, built-ins, upgraded finishes |
| Legal basement apartment | Top of the range; our 1,200 sq ft suite example: $90,000 to $120,000 | Fire separation, egress windows, separate entrance, kitchen, bathroom, laundry, permits and inspections |
For example, our Open-Concept Basement Suite in Oshawa, about 1,200 sq ft with a full kitchen, bathroom, powder room and laundry, falls in a $90,000 to $120,000 range.
Typical ranges for planning, not a quote. Your written estimate is itemized after a free site visit.
Where the money goes in a basement renovation
| Where the money goes in a basement renovation | Typical share |
|---|---|
| Framing, insulation and drywall | 28% |
| Electrical, lighting and HVAC | 18% |
| Plumbing and bathroom | 16% |
| Trim, doors and paint | 12% |
| Flooring | 10% |
| Kitchenette and extras | 8% |
| Permits and design | 8% |
What makes a basement expensive
- Legal apartment requirements. Fire separation, egress windows, interconnected alarms, minimum ceiling heights, separate systems and more inspections.
- Bathrooms below grade. Adding a bathroom or kitchenette below the main drain can mean cutting the slab or installing a pump.
- Moisture and foundation fixes. Cracks, leaks and humidity must be dealt with first. Finishing over a damp basement is expensive to redo.
- Low ceilings, ducts and beams. Working around them takes extra framing and design.
- Electrical capacity. More circuits, pot lights and a kitchen can push you into a panel upgrade.
Smart ways to spend less on a basement
- Rough in for later. Run plumbing for a future bathroom now and finish it when your budget allows.
- Keep the plan open. Fewer walls and doors mean less framing, drywall and trim.
- Design around utilities. Working with the furnace, panel and drains where they are avoids costly moves.
Where not to cut: moisture control and the subfloor. Our flooring page compares subfloor systems like DRICORE and dimpled membranes.
Do you need a permit to finish a basement?
Finishing a basement generally needs a building permit, and a legal apartment always does. Whitby, for example, lists finished basements, walkouts and below-grade entrances among the projects that need one. See our Durham permit guide and legal suite guide for the rules by town.
How long it takes to finish a basement
A standard finished basement typically takes 3 to 4 weeks on site. A full legal apartment with plumbing, electrical and inspections takes closer to 2 months, plus permit time, which varies by municipality.
