Do You Need a Permit for Foundation Repair in Ontario?
Yes, for anything that changes how the house is held up. In Ontario, underpinning, basement lowering, new or enlarged openings in a foundation wall, and structural repairs to a bowing or failing wall all need a building permit from your municipality before work starts. Sealing a non-structural crack, replacing a sump pump in an existing pit, or patching a parge coat usually does not. Waterproofing sits in between, and the plumbing side of it often needs its own permit.
The rules behind it
Two pieces of provincial law do most of the work. The Building Code Act, 1992 says you cannot construct, demolish or materially alter a building without a permit from the local chief building official. The Ontario Building Code (O. Reg. 332/12) sets the technical requirements the work has to meet, including footings, foundation walls, drainage and damp-proofing.
Each city enforces those rules through its own building department: Toronto Building, City of Ottawa Building Code Services, Hamilton's Building Division, and so on. The code is the same across the province. The forms, fees, and how much detail the examiner wants on the drawings vary from one municipality to the next.
Work that needs a building permit
Underpinning. Digging below existing footings and pouring new ones, or installing helical or push piers, changes the structure that carries the house. Every Ontario municipality treats this as permit work, and the application is typically expected to include drawings sealed by a professional engineer licensed in Ontario. If you are still choosing between pier systems, our comparison of helical piers and push piers covers how each one transfers the load.
Basement lowering. Dropping the slab to gain ceiling height almost always means underpinning or bench footings, plus new drainage under the slab. Both pieces are covered by the permit.
Bowing or leaning wall repair. Steel beams, wall anchors, carbon fibre straps on a wall that has moved, or rebuilding a section of block wall are structural. Expect a permit, and expect the building department to want an engineer's design for the bracing.
New openings. Cutting a foundation wall for a walkout, a larger egress window, or a new door needs a permit, along with a lintel or header sized for the load above.
Major crack repair with structural reinforcement. A crack that has displaced, widened over time, or runs through a footing often gets more than injection. Once the repair adds steel or replaces concrete, it becomes structural work.
Work that usually does not
- Injecting a hairline or shrinkage crack with epoxy or polyurethane
- Re-parging the exposed part of a foundation wall
- Replacing a sump pump in an existing pit with the same discharge route
- Interior drainage membranes that do not alter the structure or the plumbing
- Grading soil away from the house and extending downspouts on your own lot
"Usually" matters here. A municipality can take a stricter view, and a job that starts as a simple crack repair can turn structural once the wall is opened. If the contractor finds something that changes the scope, the permit question gets asked again.
Waterproofing and the plumbing permit
Exterior waterproofing (digging to the footing, cleaning the wall, applying a membrane and replacing weeping tile) often needs no building permit when nothing structural changes. The connections are another story. Tying new weeping tile into a sump pit, installing a new sump with a new discharge, or adding a backwater valve to the main drain is plumbing work, and Ontario municipalities generally require a plumbing permit and inspection for it.
Toronto is a good example. Its Basement Flooding Protection Subsidy Program helps homeowners pay for a backwater valve, a sump pump, and severing the foundation drain from the sewer, and the work has to be done under a plumbing permit to qualify. Toronto also requires downspouts to be disconnected from the sewer system where it is feasible. If you are in the city, the Toronto service page lists what a waterproofing inspection there covers.
Steps that apply even without a permit
Locates before digging. Ontario's Underground Infrastructure Notification System Act, 2012 requires anyone excavating to request locates through Ontario One Call first. The request is free, and on an exterior waterproofing or underpinning job the contractor should handle it before the first shovel goes in.
Trees. Toronto's tree bylaw protects city trees and private trees above a certain trunk diameter, and digging inside a tree's protection zone can require a separate permit. Ottawa and several other cities have their own tree rules.
The neighbour's side. Underpinning a semi or a row house affects a shared wall and sometimes the neighbour's footing. Ontario has no party wall statute, so access and notice are handled through a written agreement. Your engineer will usually flag this early.
How the permit process tends to run
- Inspection and diagnosis. Someone has to find the cause before anything gets designed. A crack from settlement and a crack from frost or hydrostatic pressure need different fixes.
- Engineering. For structural work, an engineer prepares drawings showing the existing footing, the new support, depths, and sequencing.
- Application. You or your contractor, acting as your agent, submit the drawings with the municipal forms and fees. Under the Ontario Building Code, a municipality has 10 business days to decide on a complete application for a house. Incomplete applications reset that clock, so most delays start there.
- Inspections during the work. Underpinning is commonly inspected at the excavation and footing stage before concrete goes in. Plumbing permits get their own inspection of the backwater valve or sump connection.
- Closing the permit. The final inspection closes the file. An open permit can show up years later during a sale.
Why skipping it costs more later
Unpermitted structural work is a common finding in Ontario home inspections, and buyers' lawyers search for open or missing permits. A seller may be asked to apply for a permit after the fact, which can mean opening finished walls so an inspector can see the footing. Insurers may also ask questions after a claim if structural work was done without approval. The permit costs far less than undoing a finished basement to prove the work was done right.
Ottawa homeowners face the same rules under the same code. The Ottawa service page has the local details.
Frequently asked questions
Do you need a permit to underpin a basement in Toronto?
Yes. Underpinning alters the footings, so Toronto Building requires a building permit, and the application normally includes engineer-sealed drawings. Plan for the permit review before you book a start date.
Is a permit required for basement waterproofing in Ontario?
The membrane and weeping tile work usually does not need a building permit if nothing structural changes. Connecting drains to a new sump, changing the discharge, or installing a backwater valve generally needs a plumbing permit from the municipality.
Who is responsible for getting the permit, the homeowner or the contractor?
The legal obligation sits with the property owner, but most owners have the contractor or engineer apply on their behalf as an agent. Ask who is pulling the permit before you sign, and get the permit number in writing.
Can foundation crack injection be done without a permit?
In most Ontario municipalities, yes, as long as the crack is non-structural and the repair is limited to sealing it. If the crack has shifted, widened, or runs through the footing, have it assessed first, because the right repair may become permit work.
Get the cause diagnosed first
Whether a job needs a permit depends on what is actually wrong, and that is decided on site. Send us the address, a few photos of the crack, wall or wet spot, and what you have noticed. We arrange an inspection, identify the cause, and spell out the repair, including any permits, in a written quote. Request your free quote.