Basement underpinning in Ottawa costs approximately $400 to $650 per linear foot of foundation wall in 2026, which puts a typical detached home with 130 to 200 linear feet of perimeter at roughly $60,000 to $130,000 for the structural work alone. Priced by area, most jobs work out to $90 to $160 per square foot of basement floor. Bench footing — the cheaper alternative that builds a concrete ledge inward instead of digging beneath the footings — runs about $250 to $400 per linear foot but costs you floor space. Those numbers cover excavation, sequenced concrete pours, disposal, and a new slab;...
Underpinning works by excavating and pouring new concrete in short, alternating sections beneath the existing footings, extending the foundation downward without letting the house settle. It is slow, highly sequenced work, which is why the price is quoted per linear foot of wall rather than per square foot of floor. In Ottawa for 2026, budget $400 to $650 per linear foot for standard residential underpinning that lowers a basement by two to three feet. A century home in Sandy Hill or the Glebe w...
For a full basement lowering on an average Ottawa detached home — underpinning, new slab, drainage, waterproofing, engineering, and permits — realistic all-in totals run $85,000 to $170,000 before any finishing. Adding a finished secondary dwelling unit on top of that typically adds $70,000 to $150,...
Bench footing, sometimes called benching, is the main alternative. Instead of digging under the footing, the crew digs down inside the basement and forms an angled or stepped concrete bench along the base of the wall, which supports the existing foundation while the middle of the floor is lowered. In Ottawa it costs roughly $250 to $400 per linear foot — often 30 to 40 percent less than underpinning — and it is faster, typically three to five weeks versus six to twelve. The catch is the bench it...
Underpinning is structural work and cannot legally be done in Ottawa without a building permit. You will need stamped drawings from a licensed professional engineer showing the excavation sequence, pin lengths, section widths, and reinforcement; engineering fees typically run $3,500 to $8,000 for a residential project, plus $1,500 to $4,000 if a structural survey or soil report is required. City of Ottawa building permit fees for a project of this scale usually fall between $800 and $2,500 depen...
Lowering a floor means the sanitary drain, sump, and often the water service must be relocated deeper. Budget $6,000 to $18,000 for plumbing rework, and note that this triggers a plumbing permit and inspection of its own. Ottawa's older sewer connections sometimes require a new saddle or backwater v...
Access is the single biggest variable in Ottawa. Downtown and inner-urban lots with no rear laneway force crews to remove spoil by wheelbarrow and conveyor through the front of the house, which can add 20 to 30 percent to labour. Suburban homes where a mini-excavator and bin can sit in the driveway are cheaper per foot. Soil type matters too: Ottawa's sensitive Leda clay behaves very differently from the shallow bedrock found in parts of Kanata and Orleans, and hitting rock means hydraulic break...
This is not a job for a general renovator. Hire a foundation specialist who does underpinning routinely, works from engineered drawings, and can show you three or more completed Ottawa projects with the engineer's name attached. Verify general liability insurance with adequate coverage — $5 million is typical for structural work — and current WSIB clearance, and confirm both in writing before any deposit. A credible quote will state the linear footage, the underpinning depth, section sequencing,...
In 2026, underpinning costs about $400 to $650 per linear foot of foundation wall in Ottawa, or roughly $90 to $160 per square foot of basement floor. A typical detached home comes in around $60,000 to $130,000 for the structural work, with all-in totals of $85,000 to $170,000 once engineering, permits, slab, and drainage are included.
Yes. Bench footing runs about $250 to $400 per linear foot in Ottawa, typically 30 to 40 percent less than underpinning, and takes less time. The trade-off is that the concrete bench takes up 12 to 24 inches around the perimeter of the basement, reducing usable floor space.
Yes. Underpinning is structural work that requires a City of Ottawa building permit and stamped drawings from a licensed professional engineer. Multiple inspections are required during construction, and relocating drains triggers a separate plumbing permit.
The excavation and concrete work usually takes six to twelve weeks for an average Ottawa home, plus four to eight weeks beforehand for engineering and permit approval. Bench footing is faster, generally three to five weeks of on-site work.
Most Ottawa projects lower the floor by two to three feet, taking a 6-foot-4 basement to roughly 8 feet or more of finished height. Going deeper than about three feet significantly increases engineering complexity and cost.