TMDC Group
Basement Underpinning
Lower your basement. Build a rental suite. Protect your foundation.
Basement Underpinning in Toronto & the GTA
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Whether you’re looking to add headroom, create a legal rental unit, or stabilize a compromised foundation — our team of licensed underpinning experts is here to guide you from start to finish.
What Is Underpinning?
Underpinning is a construction process that extends the depth of your existing foundation, allowing you to lower your basement floor and gain significant ceiling height, or to stabilize and strengthen a foundation that has shifted or settled over time.
For Toronto homeowners, underpinning is one of the smartest investments you can make. A finished basement with proper ceiling height adds livable square footage, increases your home’s resale value, and in many cases, creates the opportunity to add a legal secondary suite that generates rental income.
At TMDC Group, we handle every aspect of the process, from permits and structural engineering to excavation, concrete work, and finishing. You tell us what you want to achieve, and we take care of the rest.
Is Underpinning Right for You?
Homeowners across the GTA come to us for underpinning for a variety of reasons. Here are the most common ones:
Low Ceiling Height?
Dig Down for More Headroom. Many Toronto homes - especially older properties — have basements that are simply too short to be functional living space. Underpinning lowers the floor to give you the ceiling height you need to turn that space into something you'll actually want to use.
Create a Legal Basement Suite & Earn Rental Income
A finished, legal basement apartment can generate significant monthly rental income. Underpinning is often the first and most important step to meet minimum ceiling height requirements for a legal rental unit in Toronto.
Stabilize a Settling or Cracked Foundation
If you've noticed cracks in your foundation walls, sticking doors, or uneven floors, your foundation may be shifting. Underpinning reinforces and stabilizes your home's structural base, protecting your investment for decades to come.
Adding a Basement Suite for Family
Many Toronto homeowners are using underpinning to create a private, self-contained space for aging parents or adult children, without the cost of a home addition. A properly lowered and finished basement gives your family the independence, under the same roof.
Why Choose TMDC GROUP for UNDERPINNING
Underpinning is one of the most technically demanding and high-stakes renovation projects a homeowner can undertake. It requires experience, precision, and strict adherence to safety standards. That’s exactly what we bring to every project.
A Team You Can Trust With Your Home's Foundation
- Over 21 years of experience in residential construction across the GTA
- Licensed, insured, and fully compliant with Ontario Building Code
- We handle permits, you never have to chase paperwork
- Strict timelines and consistent communication throughout
- Award-winning service, rated on Houzz and HomeStars
- We can take your basement from underpinning to fully finished
What's Included in Our Underpinning Service
We offer a complete, end-to-end underpinning service so you’re never left chasing multiple contractors. Our team handles every phase of the project under one roof.
Underpinning requires a building permit in Toronto. We file and manage all necessary permits on your behalf, ensuring full compliance with the Ontario Building Code before a single shovel hits the ground.
Our team works with licensed structural engineers to assess your existing foundation and design an underpinning plan that is safe, code-compliant, and tailored to your home’s specific conditions.
We carefully excavate below your existing footings in sections, keeping your home safe and stable throughout the entire dig-down process.
New concrete underpins are poured and cured to form a reinforced, extended foundation. We also include waterproofing to protect against moisture, a critical step for any below-grade living space.
For homes with shifting or damaged foundations, we repair existing cracks, reinforce compromised sections, and restore the structural integrity of your home’s base.
Once the underpinning is complete, our team can take you all the way through to a finished basement — framing, insulation, drywall, flooring, plumbing, and electrical — so you don’t have to start over with a new contractor.
Room renovations
We are the General contractor for your home renovation project in GTA. At TMDC Group, we offer a wide range of room renovation services to meet your needs and preferences. Whether you’re looking to update your basement, kitchen, bathroom, or any other room in your home, our team of experts is here to help you bring your vision to life.
Ready to Unlock the Potential Below Your Home?
Hire a professional team with over 21 years of experience to handle your underpinning project from permits to completion. Get in touch today for a free, no-obligation estimate — we promise you’ll only pay what you’ve been quoted.