A legal basement apartment doesn’t just need to meet building codes—it should feel like a welcoming home. Many homeowners in Durham Region are converting their basements to generate rental income or add flexible living space for family, but creating a unit that’s both comfortable and compliant takes planning.
At Wilworks Renovations, we’ve completed dozens of legal basement apartment projects across Oshawa, Whitby, Courtice, and Bowmanville. Here’s what we focus on to make sure every suite looks great, functions smoothly, and passes inspection the first time.
1. Bring in Natural Light
Nothing transforms a basement faster than light. Larger or additional windows make the space feel more like a main-floor apartment and help it meet egress (escape) code requirements.
Code connection:
Durham municipalities require at least one egress window per bedroom, large enough for safe exit in case of emergency. The minimum unobstructed opening is 0.35 m² (3.8 ft²) with no dimension smaller than 380 mm (15 in). Wilworks partners with Oakridge Plumbing and local excavation crews to enlarge window openings safely and install compliant window wells with proper drainage.
2. Plan Smart Layouts for Compact Spaces
Basement suites are often smaller than the main floor, so every inch counts. We plan layouts that balance privacy, storage, and natural flow.
Wilworks tips:
Keep bedrooms and living spaces away from furnace or laundry areas.
Use open-concept kitchen/living zones to create visual space.
Build utility chases that conceal ductwork and plumbing without stealing ceiling height.
Consider pocket doors and wall-mounted vanities to save room.
Code connection:
Legal basement apartments must have a minimum ceiling height of 1.95 m (6 ft 5 in) in living areas. Wilworks checks this during design—lower ductwork or bulkheads can cause compliance issues if not planned early.
3. Prioritize Soundproofing and Fire Separation
Sound control isn’t just about comfort—it’s also a legal requirement for fire and safety. The Ontario Building Code (OBC) sets minimum Sound Transmission Class (STC) and Fire Resistance Ratings (FRR) between units.
Code connection:
Fire separation: Minimum 30-minute fire-resistance rating between suites (often achieved with 5/8-inch Type X drywall on resilient channel).
Soundproofing: Minimum STC 50 between dwelling units. This can include mineral wool insulation, acoustic caulking, and resilient channels to decouple drywall from joists.
Mechanical isolation: Ducts must be separated to prevent sound and smoke travel between units.
Wilworks design tip:
We combine fire-rated drywall, acoustic batts, and sound-isolating clips to meet both sound and fire code—so tenants enjoy peace and privacy while the suite stays fully compliant.
4. Choose Durable, Low-Maintenance Finishes
Basements have unique moisture and temperature challenges, so materials matter.
Recommended materials:
Flooring: Luxury vinyl plank (LVP) or tile—water-resistant and warm underfoot.
Walls: Mold-resistant drywall with proper vapor barriers.
Trim & doors: MDF or PVC trim that won’t warp with humidity.
Lighting: LED pot lights with low heat output and high brightness.
Code connection:
All materials near mechanicals or electrical systems must meet flame-spread rating requirements. Wilworks ensures every finish—especially around the kitchen and utility room—meets those standards.
5. Include Safe and Accessible Entry Points
A separate entrance isn’t just convenient—it’s mandatory for legal secondary suites.
Code connection:
Private entrance with a minimum width of 810 mm (32 in).
Proper exterior lighting for safety.
Landing and stairs that meet code for rise/run and handrail requirements.
Wilworks often integrates the entrance into an existing side yard or under a deck, ensuring proper drainage and grading to prevent water issues later.
6. Comfort and Ventilation Matter
Even if a basement suite meets the technical code, it won’t feel livable without good air movement and temperature control.
Wilworks approach:
Coordinate with HVAC Zack to balance heating and cooling between upper and lower units.
Install return air vents in main rooms to keep air fresh.
Include proper exhaust fans in bathrooms and kitchens with exterior venting.
Code connection:
Basement apartments require independent or balanced mechanical ventilation, meeting OBC Part 9 requirements for air change rates.
7. Waterproofing Before Finishing
A dry basement is the foundation of everything else. If water is getting in, finishes won’t last. Before any framing or drywall, Wilworks inspects for cracks, dampness, or grading issues.
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Building for the Long Term
A legal basement apartment done right is a long-term investment. Wilworks Renovations coordinates design, code compliance, waterproofing, and finishing under one roof—so you don’t have to juggle multiple contractors or worry about inspection surprises.
We serve Oshawa, Whitby, Courtice, Bowmanville, Ajax, and Pickering, helping homeowners create safe, modern, income-ready suites that last.