Bottom line first: A building permit is mandatory for all basement underpinning in Toronto. No exceptions. Any contractor offering to "skip the permit" is exposing you to stop-work orders, insurance voids, and sale complications - not saving you money or time.
Why a Permit Is Always Required
Basement underpinning modifies the structural foundation of the building. Under the Ontario Building Code (OBC) and City of Toronto municipal bylaws, any work that alters or extends a structural footing requires a building permit. The permit process exists to ensure that the work is designed by a licensed structural engineer, reviewed by the City, and inspected at critical stages - protecting both the homeowner and the public.
Toronto also requires permits to maintain a record of what was done to a building's structure. This record affects mortgage approvals, home insurance policies, and property disclosures when you sell. Unpermitted structural work creates legal and financial risk that can follow the property for decades.
What the Permit Application Requires
Engineering Documents
- Stamped drawings from a licensed P.Eng.
- Excavation sequence plan
- Section dimensions and depths
- Concrete mix design specifications
- Reinforcement details (if applicable)
- Shoring or temporary support plans
Application Package
- Completed Schedule 1 (designer information)
- Property survey or site plan
- Existing foundation plan
- Proposed foundation plan
- Declared construction value
- Permit fee payment
The most common reason a permit application is delayed is an incomplete submission - typically missing a page of stamped drawings, incorrect construction value declarations, or a site plan that does not show the property boundaries clearly. BaseWorks prepares the full application package and reviews it for completeness before submission. For a sense of how this fits into the overall schedule, see our guide to how long basement underpinning takes in Toronto.
How Long Does the Permit Take?
The City of Toronto targets a 20-business-day review period for most residential structural permits. In practice, underpinning permits typically take 4 to 8 weeks from submission to issuance - sometimes longer in high-volume periods or for properties in heritage conservation districts.
If the City reviewer requests revisions (known as a deficiency notice), the clock resets. Revision requests are common when drawings are missing dimensions, the sequence plan is unclear, or the declared project value does not match the scope. A single revision cycle can add 2 to 4 weeks. Submitting a complete, precise application on the first attempt is the most reliable way to stay on schedule.
How to Apply: Step-by-Step
Hire a Structural Engineer
The engineer visits the site, assesses the existing foundation, and produces stamped drawings. This typically takes 1 to 3 weeks. BaseWorks works with Toronto-licensed structural engineers who have submitted and approved underpinning drawings with the City many times.
Prepare the Application Package
Compile all required documents: Schedule 1, engineer drawings, site plan, existing and proposed foundation plans, and fee calculation. Errors in any document cause delays. Double-check that all drawings are stamped with the engineer's professional seal and signature.
Submit to the City of Toronto
Submit online through the City's Toronto Building portal, in person at a Toronto Building counter, or by mail. Online submissions are generally faster for tracking status. Pay the permit fee at submission - the fee is based on declared construction value.
Respond to Any Deficiencies
The City reviewer may issue a deficiency notice requesting clarification or additional information. Respond promptly with the revised documents. Fast responses minimize the time the application spends in revision.
Receive and Post the Permit
Once approved, the permit is issued. It must be posted visibly on the property before any work begins - this is a legal requirement. The permit specifies which inspections are required and when.
Schedule and Pass City Inspections
The City performs inspections at key stages: typically before concrete is poured in certain sections and at project completion. BaseWorks schedules inspections directly with the City and notifies homeowners in advance. The permit closes when the final inspection passes.
Permit Cost Breakdown
Toronto building permit fees for underpinning are calculated as a percentage of the declared construction value. As of 2026, the base rate is approximately 1.1% to 1.5% of the declared project value, subject to the current City fee schedule.
- Underpinning project at $50,000 declared value: approximately $550 to $750 in permit fees
- Underpinning project at $80,000 declared value: approximately $880 to $1,200 in permit fees
- Structural engineer drawings: approximately $2,000 to $5,000 depending on complexity
These are in addition to the construction costs. BaseWorks includes permit management in every underpinning contract - the application, engineering coordination, and inspection scheduling are handled as part of the project. For real project figures, see our basement underpinning cost breakdown.
Warning: Doing underpinning without a permit exposes you to stop-work orders, mandatory exposure of completed work for after-the-fact inspection, potential enforcement orders, and insurance voids. It also creates disclosure obligations that can complicate or kill a future property sale. No savings are worth these risks.
What the City Inspects and When
The permit does not end when it is issued. It sets out a series of inspections, and the work has to pass each one before the next stage can proceed. Knowing the rhythm helps you understand why a project occasionally pauses for a day or two without anything being wrong.
Inspections are tied to the stamped drawings. Before concrete is placed in critical sections, the City may want to see the excavation, the cleaned bearing surface and any reinforcement. Later inspections cover the completed footings, the drainage and gravel base under the new slab, and the final completed work. The inspector compares what has been built to the engineer's drawings, so the drawings are effectively the checklist.
Your contractor books each inspection directly with the City, usually with short notice from the inspector's side. The practical effect for you is that you may see the crew wait for an inspection before pouring. That wait is part of how the permit protects you, since the inspector sees the footing before it is buried in concrete.
Documents to Keep After the Permit Closes
When the final inspection passes and the permit closes, collect a small file of records. They matter more than most homeowners expect, especially when you refinance, insure or sell.
- The issued permit and the final inspection record. This is proof that the work was approved and completed.
- The stamped engineering drawings. They show exactly what was built and at what depth.
- Any engineer's field review letters. They confirm the work followed the design.
- Concrete delivery tickets or test results, where they were part of the specification.
- Your contract, change orders and warranty. They define who is responsible for what.
A buyer's lawyer or home inspector will often ask for these. Having them ready avoids delays at closing and supports the value you gain from the project. Our basement lowering permit guide covers the same process from the lowering side if your goal is ceiling height as well as structural support.
Common Reasons Applications Are Sent Back
Most delays are avoidable. The usual causes are drawings missing a page or a dimension, a declared construction value that does not match the scope, a site plan that does not clearly show the boundaries, and an unclear excavation sequence. A less obvious cause is a mismatch between the engineer's drawings and the application form, such as different addresses or descriptions of the work.
A careful contractor reviews the package line by line before it is submitted, because each revision cycle can add weeks. It is also worth asking whether the engineer has submitted underpinning drawings to the City before. Experienced engineers know what reviewers look for and tend to produce drawings that pass the first time. If you are comparing contractors, our guide to questions to ask a basement underpinning contractor includes how they handle permits.
Frequently Asked Questions
Yes, always. Basement underpinning modifies the structural footing of the building - it is a structural alteration that cannot be done without a building permit under the Ontario Building Code and City of Toronto permit bylaws. No exceptions apply to residential underpinning.
The permit fee is calculated as approximately 1.1% to 1.5% of the declared construction value. For a typical underpinning project valued at $50,000 to $80,000, permit fees generally run $550 to $1,200. Engineering drawings add $2,000 to $5,000 depending on complexity.
Generally 4 to 8 weeks from a complete submission. Incomplete submissions - missing dimensions, unstamped drawings, incorrect fee calculations - restart the clock when revisions are requested, adding weeks. A complete, precise submission is the only reliable way to minimize wait time.
Yes. The City of Toronto requires stamped drawings from a licensed structural engineer (P.Eng.) for all underpinning permit applications. The engineer specifies footing dimensions, excavation sequence, concrete mix design, and reinforcement requirements. No permit application is complete without these drawings.
The City of Toronto can issue a stop-work order immediately. If discovered after completion, the homeowner may need to expose footings for inspection, hire an engineer to certify the work at their own cost, or in extreme cases undo and redo the work with proper permits. Home insurance may not cover structural work done without a permit, and unpermitted work creates disclosure obligations that complicate future property sales.
Yes. BaseWorks manages the entire permit process: coordinating with the structural engineer, preparing the application package, submitting to the City of Toronto, responding to reviewer comments, and scheduling all required City inspections throughout the project. Permit management is included in every BaseWorks underpinning contract.
Either can be the applicant, but most homeowners have their contractor manage it, since the contractor coordinates the engineer, the drawings and the inspections. Confirm in your contract who is responsible and that the permit will be issued before any work begins.