Basement Apartments & Secondary Suites in Toronto: Complete 2026 Guide
Everything you need to know about creating a legal basement apartment in Toronto. Requirements, permits, costs, and recent code changes explained.
What You Need to Know
*Existing ceilings only. New ceilings need 5/8" Type X.
Good News for Homeowners
Since 2022, Toronto allows secondary suites in virtually all residential zones. You no longer need a zoning variance in most cases. However, you still need a building permit and must meet building code requirements.
What Makes a Basement Apartment "Legal"?
A legal secondary suite in Ontario needs to check every box on this list:
The Non-Negotiables:
- Minimum 14.0 m² (145 sq ft) floor area for a bachelor unit
- Ceiling height of at least 1.95m (6'5")
- Separate entrance from the main dwelling (recommended, not always required)
- Full kitchen with cooking facilities
- Full bathroom
- Proper fire separation from the main unit
- Egress window in every bedroom
- Smoke and carbon monoxide alarms (interconnected with the main unit)
- Building permit and inspections
Warning
Miss any of these and you're operating an illegal unit. That means your insurance won't cover incidents, you could face municipal fines, and you might be forced to demolish the kitchen.
Ceiling Height Requirements
This is where most older homes run into trouble.
Ceiling Height Requirements
Good News
The current code allows 1.95m instead of the old 2.1m requirement for existing homes. That's an extra 6 inches of flexibility.
If your basement ceiling is too low, you have two options:
1. Underpinning
Lowering the basement floor by excavating beneath the foundation.
Gives you full ceiling height
2. Bench Footing
A cheaper alternative that creates a ledge around the perimeter.
Lose floor space but gain ceiling height in centre
Most homes built before 2000 have basement ceilings around 6'2" to 6'8". The new 1.95m (6'5") minimum means more basements now qualify without major structural work.
Fire Safety Requirements
This is where most renovations fail inspection. You need to stop fire and smoke from travelling between units.
The "Smoke-Tight" Exception (New for 2025)
For detached homes with interconnected smoke alarms, the Code allows for a Smoke-Tight Barrier compliance path. While this waives the need for a tested 45-minute assembly, you must still use 15.9mm (5/8") Type X fire-rated drywall on walls and ceilings to meet the standard. You cannot use standard 1/2" drywall.
Key Requirements:
- Resilient Channel (Sound & Fire)The OBC requires STC 50 for sound separation between apartments/units. This can be achieved by installing Resilient Channel (sound bars) with 5/8" Type X drywall and batt insulation in the ceiling cavity.
- DoorsThe door connecting the basement to the main floor (if one exists) must be a 20-minute fire-rated door or solid wood (minimum 45mm thick) with a self-closing device.
- HVAC & Ducting (Don't Forget This)Smoke travels through vents. If your furnace serves both units, you have two choices:
- Duct Dampers: Install fire dampers inside the ducts where they pass through the ceiling (costly and messy).
- Separate Systems: Keep the furnace for the main floor and install electric baseboards or a heat pump for the basement.
- AlarmsSmoke and CO alarms must be interconnected. Wireless interconnection is now allowed for the signal to talk to each other, but units typically still need hardwired AC power.
Egress Windows
Every bedroom in your basement suite needs a window large enough for an adult to escape through in an emergency.
Egress Window Requirements:
- Minimum opening area: 0.35 m² (3.77 sq ft)
- Minimum dimensions: 380mm (15") both height and width
- Sill height: Max 1m (39") above floor (if higher, you must install a permanently built-in step).
- Must open from inside without tools or keys
- Window well clearance: 760mm (30") minimum from the foundation
Cost
$3,000-$8,000 per window installed, including excavation, window well, and drainage.
If your basement windows are too small (most older homes have those tiny slider windows), you'll need to cut into the foundation wall to install proper egress windows. Budget for this early - it's not optional.
The Permit Process
You can't just renovate and hope for the best. Here's the actual process:
1. Verify Zoning
Check with your municipality that your property allows secondary suites. Minor variances may be needed if you don't meet setbacks.
2. Hire a Designer
Get architectural drawings showing floor plans, ceiling heights, fire separations, and egress windows
3. Apply for Permit
Submit drawings to your local building department. See our guide on how to apply for a permit.
4. Schedule Inspections
Framing, electrical, plumbing, insulation, drywall, and final. Read our inspections guide to prepare.
5. Get Certificates
ESA (electrical), fire authority, and municipal compliance
6. Register the Suite
Many municipalities require registering your secondary suite
Timeline
Expect 4-8 weeks for initial permit review (due to staffing shortages), then 2-4 months for construction and inspections.
Permit & Design Costs
According to the Government of Ontario, secondary suites in existing homes are exempt from development charges (for the first additional unit). That's a significant savings - development charges in the GTA can run $30,000+.
What Does It Actually Cost?
Here's what a complete legal basement apartment typically costs in the GTA:
Complete Cost Breakdown
The Financial Case for Going Legal
Yes, legal suites cost more upfront. But consider what you're getting:
Income Potential
That's $18,000-$30,000 per year in rental income. Legal basement apartments in the GTA command premium rents.
Insurance Coverage
Your homeowner's insurance actually covers the rental unit. With illegal suites, you're fully exposed to liability and property damage claims.
Resale Value
Legal secondary suites add significant value to your home. Buyers know they're getting permitted income potential, not a liability that might need to be removed.
Financing Options
The CMHC Refinance for Building Secondary Suites allows homeowners to access insured financing by refinancing their existing mortgage up to 90% of the post-renovation value of their home.
- • Up to 30-year amortization
- • Property value limit of $2 million
- • You (or close relative) must occupy one unit
Compare that to an illegal suite where you're collecting rent illegally, have no insurance coverage, and might be forced to rip everything out if an inspector shows up.
New vs Old Homes: Different Rules
The Ontario Building Code treats homes differently based on age:
Code Requirements by Home Age
*Applies to existing ceilings only. New ceilings require 5/8" Type X.
If your home is more than 5 years old, you have more flexibility. The code recognizes that retrofitting older homes to brand-new standards isn't always practical or affordable.
See Approved Basement Apartments Nearby
Research permits approved in your neighborhood.
Want to check the status of your own application? Use our permit status guide.