Scarborough has some of the best basement renovation candidates in Toronto. Many neighbourhoods, from Wexford and Dorset Park to Agincourt, Guildwood, and Cliffcrest, are full of 1950s and 1960s bungalows and backsplits with full-height basements that were built for storage and a laundry tub, not for living. Newer homes in areas like Morningside Heights and Rouge have different issues. This guide covers what to check before you start a basement renovation in Scarborough, which permits apply, and how to plan the layout, based on about 20 years of hands-on construction and roughly 15 years as a home inspector.
Key Takeaways
- Deal with moisture first: grading, downspouts, cracks, and old weeping tile come before drywall.
- Most finished basements in Toronto need a building permit when you add walls, plumbing, or change the layout.
- New electrical work needs an Electrical Safety Authority (ESA) permit and a Licensed Electrical Contractor.
- Bedrooms need a proper egress window, and a legal second unit has extra fire, height, and exit rules.
- Older Scarborough homes often hide outdated wiring, galvanized pipes, or clay drains that are cheaper to fix while walls are open.
What makes Scarborough basements different?
Post-war Scarborough bungalows usually have poured concrete or concrete block foundations, original clay or early plastic drain lines, and basements that have been partly finished more than once. We often find wood paneling over damp walls, carpet laid straight on concrete, and wiring added by previous owners without permits. Backsplits have split-level basements with lower ceilings in some areas, which affects where bedrooms and bathrooms can go. Newer homes in the east end usually have better insulation and drainage, but can still have settling backfill and window well problems.
How do you check for moisture before finishing?
- Walk the outside after rain and check that the ground slopes away from the house.
- Make sure downspouts discharge well away from the foundation.
- Inside, look for efflorescence (white powder), tide lines, rusty nails at the bottom of old framing, and musty smells.
- Check for cracks in the walls and at the floor-wall joint.
- Test for high humidity, especially in summer, when condensation can look like a leak.
- Consider a camera inspection of the main drain in older homes before you build over it.
If there is an active leak, fix it before finishing. Our guide to basement waterproofing in Scarborough explains interior and exterior options.
Do you need a permit to finish a basement in Scarborough?
Scarborough is part of the City of Toronto, so permits go through Toronto Building. In general, finishing a basement with new walls, a new bathroom, or changes to the layout needs a building permit. Simple cosmetic work, like replacing flooring or repainting, usually does not. Any new or altered electrical work needs an ESA permit, and new plumbing, including a basement bathroom or a backwater valve, falls under the building permit. Creating a legal second unit (basement apartment) has its own requirements for fire separation, smoke and carbon monoxide alarms, ceiling height, and exits. Always confirm the exact permit path for your scope with Toronto Building before work starts.
What layout works best in a Scarborough basement?
| Plan | Works well when | Things to plan for |
|---|---|---|
| Open family room | Bungalow with a clear span and few posts | Lighting layout, insulation, and sound control under bedrooms |
| Bedroom and bathroom | Teenager, guests, or aging parents | Egress window, bathroom ventilation, drain location |
| Home office or gym | Working from home, quiet space needed | Dedicated circuits, ventilation, flooring for equipment |
| Second unit | Rental income or multigenerational living | Separate entrance, fire separation, permit, and higher budget |
Where the existing drain and stack sit usually decides where a basement bathroom goes. Moving it far means cutting more concrete, so a good layout starts from what is already there.
What should you upgrade while the walls are open?
- Old wiring, overloaded panels, and ungrounded circuits, done by a Licensed Electrical Contractor under an ESA permit.
- Galvanized supply pipes and old cast iron or clay drains.
- A backwater valve if the basement drain could back up during heavy storms.
- Insulation on exterior walls and rim joists, with an air and vapour barrier detailed correctly.
- Ductwork and returns so the basement actually heats and cools.
- Smoke and carbon monoxide alarms on every level.
Scarborough Basement Renovation Checklist
- Fix grading, downspouts, and any active leaks.
- Remove old paneling or carpet and check what is behind it.
- Decide the layout around existing drains, posts, and windows.
- Confirm permits with Toronto Building and ESA.
- Plan egress windows for any bedroom.
- Upgrade wiring, plumbing, and ductwork before insulation.
- Choose moisture-tolerant flooring suitable for concrete.
- Book inspections at each stage before closing walls.
Why hire a licensed contractor with inspection experience?
Basements hide problems, and older Scarborough homes hide more than most. Nehan Construction is led by a licensed contractor with about 20 years of hands-on construction experience, construction engineering training from George Brown College (Building Renovations), and roughly 15 years of home inspection experience, among the top inspectors in Ontario. That means we find moisture, wiring, and drain issues before they get covered up. We are fully insured with WSIB coverage, use licensed electrical, plumbing, and HVAC subcontractors, and build to the Ontario Building Code. Learn more about Nehan Construction and our home inspection background.
See our basement renovation in Toronto page and our waterproofing services. Renovating upstairs as well? Read our Scarborough kitchen renovation guide or visit our bathroom remodel in Scarborough page.
Nehan Construction works across Scarborough, including Agincourt, Wexford, Guildwood, Cliffcrest, Birch Cliff, Malvern, and Morningside, plus Pickering, Ajax, and the wider GTA. Call 647-704-7100 or email nehanconstruction@gmail.com. After a site visit, we will give you an honest written scope.
Frequently Asked Questions
Do I need a permit to finish my basement in Scarborough?
Usually yes, if you are adding walls, a bathroom, or changing the layout. Permits go through Toronto Building, and electrical work needs a separate ESA permit.
Can I add a bedroom in my Scarborough basement?
Yes, but it needs a window large enough for emergency exit, plus smoke and carbon monoxide alarms. Check the window size before planning the room.
Should I waterproof before finishing the basement?
Yes. Fix grading, downspouts, and leaks first. Finishing over a damp wall leads to mould and costly tear-outs.
Is my old Scarborough bungalow wiring safe to keep?
It depends. Many older homes have ungrounded circuits or past amateur work. A licensed electrician should assess it while the walls are open.
How do I get started with Nehan Construction?
Call 647-704-7100 or email nehanconstruction@gmail.com with a few photos. We will book a site visit and walk through the space with you.
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