How Basement Lowering Works
Underpinning is the process of extending or stabilizing an existing foundation, usually done to strengthen the structure or increase the ceiling height in a basement. Lowering a basement floor is a complicated, laborious job but well worth the effort and expense when it comes to adding comfort and value to any house. A deeper foundation means more headroom and overall area in a basement — an essential quality of a great, livable space.
Basement underpinning requires architectural drawings that have been engineer approved, a building permit from the City of Toronto, and then the tools, skills and knowledge of an underpinning professional. This is definitely not a do-it-yourself job! We take care of your underpinning job properly and professionally from sourcing engineers to helping with permits and rebate applications to coordinating City of Toronto building inspections.
Why Choose Cornerstone for Underpinning?
At Cornerstone Waterproofing Inc., we are underpinning professionals. We take care of your underpinning job properly and professionally from sourcing engineers to helping with permits and rebate applications to coordinating City of Toronto building inspections. We secure the existing foundation, remove the old concrete floor and plumbing, dig and dispose of the soil, reinstall drains, pipes, and an interior weeping tile system, re-pour gravel and then install a new concrete floor.
- Gain full ceiling height for legal suites, family rooms, or home gyms.
- Saverio's dedicated crew manages engineer approvals, permits, and City of Toronto inspections from start to finish.
- Opportunity to upgrade drainage, install weeping tile, and add a sump pump while the floor is open.
- Increase property value without altering the home's footprint.
- 20 year structural warranty on all underpinning work (call for details).
Ready to get started?
Call 416-879-4593 or request your free estimate online.
Our Staged Underpinning Process
Lowering a basement safely requires a methodical approach. We follow engineered plans and strict municipal codes to protect your home's structural integrity.
Assessment & Engineering
Saverio meets you onsite to assess your basement. An engineer measures the space and draws up a plan showing how much height you can gain.
Permits & Approvals
We handle the engineering drawings, permit applications, and coordinate with the City of Toronto.
Excavation & Construction
We dig out in stages to keep your home stable, install drainage and waterproofing, and pour a new concrete floor at the lower depth.
Inspections & Handover
The City signs off, and we hand over your permits, drawings, and warranty documentation.
Why Underpin Your Toronto Home?
Ready to Unlock Your Basement's Potential?
Schedule a site visit with Saverio to discuss underpinning options, ceiling height goals, and structural requirements for your home.
Understanding Underpinning Costs
Basement lowering is a significant investment. Costs are generally calculated per linear foot of foundation wall underpinned, plus the square footage of the new concrete slab. The final price varies based on several key factors:
Service Areas
Serving Toronto's Older Neighborhoods
We frequently underpin and lower basements in East York, North York, The Beaches, Leslieville, High Park, and throughout the GTA where older homes need more headroom.
20-Year Structural Guarantee
A lowered basement is a permanent upgrade. Our underpinning structural work is backed by a robust 20-year warranty.
Get Your Free How Basement Lowering Works Estimate
Speak with Saverio directly about your project. No obligation, no pressure — just honest advice from someone with 20+ years of experience.