Basement Renovation
Basement Renovation in Toronto & the GTA
From finishing an empty basement to underpinning, waterproofing and legal basement apartments, TGV Construction Group plans, permits and builds the whole job with one team. Free quotes across the Greater Toronto Area.
01
Basement Finishing & Renovation
An unfinished or dated basement is the most affordable extra living space in a GTA home. We take it from bare concrete or an old 1980s rec room to a finished, permitted space: a family room, a home office, a gym, a guest suite or a play area for the kids.
We plan the layout with you, take care of the permit and run every trade under one contract, so you deal with one team from the first site visit to the final inspection.
Basement finishing includes:
- Framing and insulation
- Drywall and ceilings
- Pot lights and electrical
- Flooring
- Laundry rooms
- Home offices and gyms
- Wet bars and kitchenettes
- Storage and millwork
02
Underpinning & Basement Lowering
Many Toronto houses were built with low basements. Underpinning digs the floor down and extends the foundation below the old footings, so the basement gets full ceiling height and can become real living space or a separate unit.
Underpinning is structural work. It is designed by a structural engineer, needs a building permit and is done in sections so the house stays supported the whole time. Where full underpinning is not needed, a bench footing can lower the floor at a lower cost - we will tell you which one your house needs after the site visit.
Our structural basement work:
- Underpinning
- Basement lowering
- Bench footings
- Foundation repair
- New concrete floors
- Walkout entrances
03
Basement Waterproofing
A basement has to be dry before it is finished. Water behind new drywall turns into mould and a second renovation, so every basement we finish starts with a moisture check.
If there are cracks, leaks or past flooding, we fix the cause first. And if water is coming in right now, our emergency restoration team answers 24/7.
- Foundation crack repair
- Interior waterproofing
- Exterior waterproofing
- Drainage and sump pumps
- Moisture and mould checks
- Flooded basement clean-up
04
Basement Apartments & Second Units
A legal basement apartment can bring rental income or a home for family. Ontario allows second units in most houses, but the space has to meet the Ontario Building Code and fire code: ceiling height, exits, fire separation, smoke alarms, windows and a separate entrance.
We plan the unit around those rules from the start and build it under a permit, so it passes inspection and can be rented legally.
- Separate side or walkout entrance
- Kitchen and bathroom
- Fire separation
- Egress windows
- Sound insulation
- Permit drawings and inspections
05
Basement Bathrooms
A bathroom is the most requested upgrade in a basement and one of the bigger cost items: the concrete floor is opened to tie into the drains, or a lift system is added where the drains are too high. In the GTA, a basement bathroom typically adds $15,000 to $35,000 to a project.
- Walk-in showers
- Floor drains and rough-ins
- Ventilation
- Tile and vanities
Planning your budget
How much does a basement renovation cost in Toronto?
A finished basement in the GTA typically costs $40,000 to $80,000, depending on the size of the space, its condition and how far you take the finishes. Per square foot, most GTA basement projects land between $55 and $95, with premium finishes and full legal suites at the top of that range. A basement bathroom adds $15,000 to $35,000.
These are typical ranges, not a quote. Underpinning and waterproofing depend on the house, the soil and the engineer's design, so we price them only after a site visit. Every TGV quote is free.
For a detailed breakdown, read our guide Basement Renovation Cost in Vaughan, which applies across the GTA.
How we work
From first visit to final inspection
- Site visit. We look at the basement, check for moisture and ceiling height, and listen to how you want to use the space.
- Free quote. A written quote with the scope of work, so you can compare it line by line.
- Design and permit. Drawings, engineering where needed, and the building permit from your city.
- Construction. One team runs every trade, with the work area closed off from the rest of the house.
- Inspections. We book the city inspections at each stage and fix anything the inspector asks for.
- Handover. A final walkthrough with you before we call the job done.
Where we work
Basement renovation across the GTA
We renovate basements in Toronto, Scarborough, North York, Etobicoke, Markham, Vaughan, Richmond Hill, Mississauga, Brampton, Oakville, Burlington, Milton, Newmarket, Pickering, Ajax, Whitby and Oshawa.
Questions
Basement renovation questions
How much does a basement renovation cost in Toronto?
A finished basement in the GTA typically costs $40,000 to $80,000, or about $55 to $95 per square foot, depending on size, condition and finishes. A basement bathroom adds $15,000 to $35,000. These are typical ranges, not a quote - every TGV quote is free.
Do I need a permit to finish my basement?
In most cases, yes. Finishing work involves framing, electrical, plumbing and fire-safety elements regulated under the Ontario Building Code, so GTA cities require a building permit for basement finishing, for new plumbing fixtures and always for underpinning or a second unit. We prepare the drawings and apply for the permit.
How long does a basement renovation take?
Most basement renovations take several weeks to a few months from design to final inspection. Underpinning and legal basement apartments take longer because of engineering, permits and more inspections.
What is the difference between underpinning and a bench footing?
Both lower a basement floor. Underpinning extends the foundation below the old footings, so the full floor area gets the new height. A bench footing leaves a concrete ledge along the walls and is usually less expensive. A structural engineer decides which one a house needs.
Can we stay in the house during a basement renovation?
Usually yes. The work is below your living space, so the main disruption is noise, dust control and occasional power or water shutoffs. We keep the work area closed off and tell you the schedule in advance.
Does a finished basement add value to my home?
A permitted, well-built finished basement is a genuine selling feature in the GTA. It adds living space at a lower cost per square foot than an addition, and buyers ask for the permits.
Ready to finish your basement?
Tell us about your basement and we will prepare a free quote.