Basement Underpinning in North York, ON

OCM Excavation & Construction underpins North York basements from Willowdale to Bayview Village to Lawrence Park, Don Mills, Bathurst Manor and Newtonbrook. If your 1950s or 1960s North York bungalow or two-storey has a 6’6″ to 6’10” basement and you want a real lower level — a legal second suite to offset the mortgage, a media room, an in-law setup — underpinning is the work. We dig in measured pin sections, pour new piers, and lower the slab 24 to 36 inches. Call 416-317-3090 to book a North York site visit.

Why North York Homeowners Underpin

North York’s housing stock skews 1950s and 1960s — bungalows on wide lots in Willowdale, Bathurst Manor, Bayview Village and Newtonbrook, with shallow concrete or block foundations and basement ceilings that pre-date the modern code minimum. The original purpose of those basements was utilities and storage, not living space. Today the same lots sell for $1.5M and up, and North York owners want every square foot working. The two biggest reasons we are called are converting to a legal basement apartment under Toronto’s second-suite rules, and lowering the basement during a full-house renovation to get usable headroom for media, gym and family space.

North York Soil and Foundation Conditions

North York sits on Halton Till — dense clay with stones — over much of its footprint, with sandier soils near the Don Valley and west toward the Humber. Many 1950s and 1960s North York houses have shallow concrete footings or, less commonly, rubble footings on the oldest stock. Either way, the existing footings are usually not deep enough or wide enough to support an open-plan basement renovation, which is exactly why underpinning matters. We assess the existing footing condition during the site visit and design pier dimensions to match. North York basements also frequently have legacy clay weeping tile that has silted up. We replace it while the dig is open.

North York Permits

North York is part of the City of Toronto, so basement underpinning is permitted through Toronto Building, with most North York applications filed at the North York Civic Centre on Yonge Street. You need stamped structural drawings from an Ontario-licensed Professional Engineer, a site plan, and where applicable a Committee of Adjustment application if you are converting to a second suite that triggers a variance. Permit fees vary by floor area — Toronto Building publishes the current per-square-metre rate on its fee schedule. We file the permit, coordinate engineering, and book inspections at footing, framing and final.

Typical North York Underpinning Cost

For a standard North York bungalow or two-storey with a 1,000 to 1,300 square foot basement footprint, full underpinning lands in the $45,000 to $85,000 range, depending on depth lowered, exterior waterproofing scope, slab replacement, weeping tile, sump and rough plumbing for a suite. Bayview Village and Lawrence Park infill rebuilds with 1,800+ square foot basements run higher. We give a real number after the site walk, not before. Call 416-317-3090 to book the visit.

Equipment We Bring to North York

Most North York lots are wide enough to fit a Yanmar SV40 mini-excavator through a side yard. We use it inside the basement once the access is cut, which shortens the structural phase compared to hand-dig. On tighter Newtonbrook or older Willowdale lots where side access is blocked, we hand-dig and barrow out the spoil through the basement walkout or a constructed temporary opening.

Related North York Services

Most North York underpinning jobs pair with exterior waterproofing and a new weeping tile. See our North York foundation waterproofing page and our North York excavation contractor page. Neighbouring cities — see underpinning in Toronto and underpinning in Vaughan. Full coverage at our service areas.

Frequently Asked Questions

How long does North York underpinning take?

Structural underpinning runs 4 to 8 weeks on a standard North York bungalow or two-storey. Add 2 to 4 weeks for exterior waterproofing, slab replacement and rough plumbing for a secondary suite. Large Bayview Village rebuilds can run 10 to 12 weeks. Permit and engineering add another 4 to 8 weeks before we break ground.

Does the City of Toronto allow basement apartments in North York?

Yes. North York basement apartments are governed by Toronto’s second-suite rules, which permit secondary units in most residential zones citywide. The basement must hit Ontario Building Code ceiling height, egress windows, fire separation between units and HVAC requirements. Underpinning is usually how North York basements built before 1990 reach the required ceiling height.

Will underpinning damage the rest of my North York house?

Done correctly, no. We work in pin sections — typically 3 to 4 feet wide — and only excavate one section per side at a time, with the rest of the foundation fully supported throughout. Hairline drywall cracks happen occasionally and are normal. Structural movement is not. The engineered sequence is what protects the rest of your house.

What about the existing weeping tile and waterproofing?

Most 1950s and 1960s North York houses still have the original clay or perforated PVC weeping tile, often silted up. While the foundation is exposed for underpinning, we replace it in new washed stone routed to a new sump, and apply a fresh exterior waterproofing membrane to the new and existing foundation walls. This is the right and only time to do it.

Can I add a basement walkout while you underpin?

Often yes — many North York lots grade away from the rear and support a walkout cut after underpinning. We assess the rear yard grade during the site visit and let you know if it works. A walkout substantially increases the value of a basement suite, both for legal egress and for daylight.

Book Your North York Underpinning Quote

Call OCM at 416-317-3090 or use our free quote form. We will walk the basement, measure existing height, and follow up with a written number for your North York project.

Phone 416-317-3090.

Related Services in North York

• Basement Underpinning in Vaughan
• Basement Underpinning in Toronto
• Basement Underpinning in Scarborough
• Basement Underpinning in Richmond Hill
• Walk-Up Basement Conversion in North York
• Egress Window Installation in North York
• Window Well Installation in North York
• Sump Pump Installation in North York
• Foundation Waterproofing in North York
• Excavation Shoring in North York