Three quotes for the same basement routinely land 2x apart, and it is almost never about greed. It is that each quote covers different work. Tick what each bid actually includes and the tool adds back the market cost of everything excluded, so all three end up describing the same job.
What this is built from
- $11.89 per linear metre City of Toronto permit fee, applied to the perimeter you enter
- $1,500 to $2,500 stamped structural engineering, midpoint used
- $60 to $120 per linear foot for exterior waterproofing during an open excavation, midpoint used
- $12 to $18 per square foot for a new slab with gravel base and vapour barrier, midpoint used
- 10 percent notional soil contingency where a quote carries none
This is an estimate assembled from published Toronto market ranges, not a quote, and not engineering advice. Your foundation, soil, water table and access will move it. Nobody can price this work properly without looking at your footings.
What the number does not tell you
Normalising the quotes tells you what you are comparing. It does not tell you who should do the work. Before you decide, ask each bidder these, and weigh the answers at least as heavily as the price.
- What section width does your engineer specify, and in what order do you pour? Someone who has done this work answers immediately and specifically. Hesitation here is the biggest warning sign in this trade.
- How many underpinning projects have you completed in the last twelve months? You want a crew that does this repeatedly, not one that does it occasionally between kitchens.
- Who is the engineer, and can I speak to them? A contractor with a standing engineering relationship names them without hesitation.
- Can I see a project you finished more than three years ago? Fresh work always looks good. Work that is still dry and uncracked after several winters is the actual proof.
- What happens if you hit water or unexpected soil? You want a described process, not a reassurance that it will not happen.
The full version of this, including the twelve line items to demand and the warning signs worth walking away from, is on how to compare underpinning quotes.
Common questions
Why do underpinning quotes differ by so much?
Because they are usually for different work. Waterproofing in or out, permits and engineering in or out, depth, whether the new slab is included, and how soil risk is handled account for most of a 2x spread.
How does this tool normalise the quotes?
It adds the published market cost of anything a quote excludes, so every bid is expressed as the same complete scope. A cheaper quote that excludes waterproofing and permits often ends up the more expensive job.
Should I always pick the lowest normalised number?
No. Normalising tells you what you are actually comparing, not who should do the work. Sequencing knowledge, engineering relationship, references on projects several winters old, and a fair payment schedule all matter as much as the number.
What if a contractor will not itemise their quote?
Then you cannot compare their number to anything, which makes it unusable regardless of what it says. That refusal is a complete answer in itself.
Get a real range
Not a brochure. Tell us the basics and we will come back with numbers that reflect your actual foundation.