Foundation repair quotes frighten people because the range is so wide — and because most homeowners have no reference point. After 12 years of quoting these jobs, here's the honest lay of the land — plus some quick pointers, because quotes very often carry exclusions on scope.
Check what's NOT in the quote before comparing numbers. Common exclusions that surprise people later:
- Building consent, inspections, and restricted-building-work requirements, where applicable. Requirements depend on the exact work: check with the relevant council rather than relying on a general rule
- Engineer's design, PS1/PS4 producer statements, or geotech input if required
- Reinstatement — repairing the claddings, linings, decks, or landscaping disturbed to do the work (classic example: relaying the concrete pathway that was cut and dug out for underpinning)
- Drainage improvements (often quoted as “recommended extras” rather than included)
- GST
A cheap quote with heavy exclusions routinely ends up dearer than an honest all-in one.
Typical NZ ranges by job type
| Job | Typical range | What drives it |
|---|---|---|
| Drainage fix (downpipes, surface water) | $ hundreds–low thousands | Often a contributing factor to movement and settlement — many foundation repair jobs need some drainage work too |
| Single pile repair/replacement | low thousands | Access, pile type, difficulty factor and time on site to set up propping, plus any re-levelling work (time-consuming on site and can be difficult) — and check scope: new concreted posts vs jack studs only (see below) |
| Jack and pack (re-levelling settled piles) | mid–high thousands | Access, difficulty factor, time on site to set up propping, plus extra time to level the building — re-uses the existing concrete blocks/bases; shorter-term fix than repiling, and often difficult to make the old posts comply with NZS 3604 |
| Partial repile | typically $25k–$40k | Access, pile type, removal of existing posts, difficulty factor, time on site to set up propping, plus any re-levelling work (time-consuming on site and can be difficult) and access for any proposed new bearers, joists or other upgrades to suit new pile spacing (see timber note below) |
| Full repile (villa/bungalow) | with the house in place (incl. bearer upgrades): $50k–$70k; lifting the home: $100k–$140k+ | Access to the subfloor, pile depths, removal of existing posts, difficulty factor, time on site to set up propping, plus any re-levelling work and any proposed new bearers, joists or other upgrades to suit new pile spacing. Does the whole home need lifting, or can alternative methods to a digger and auger be used, such as micro-piling or hydro excavation? |
| Localised underpinning (one corner) | mid four–five figures | Depth to good ground, steel reinforcing details, access to the existing footing and difficulty, ground water present? public utilities close by? whether lifting is needed, the sequence required to do it safely, what inspections are required and at what stages, what remedial work follows completion — and can alternative methods to a digger and auger be used, such as micro-piling or hydro excavation? |
| Polyurethane injection — slab lifting/re-levelling possible | mid four to five figures | Access for technicians to drill through concrete and reach the areas needing injection, amount of expanding foam required (m³) and time on site. Check drainage close by — foam can fill drains (particularly Novacoil) and cause more issues. Can be a more short-term fix |
| Full underpinning | high five figures+ | Relatively common in 1960s–1970s cinder block/brick homes on slab or strip footings — same drivers as localised underpinning, at whole-house scale |
Timber note: it's difficult to install new SG8 square/true timber into an old, out-of-square and unlevel home — it takes a lot of “cutting in” and extra “fiddling” time on site. That time is real cost, and it's why two identical-sounding repile quotes can be far apart.
Need a property-specific number? These are Aidan's broad, experience-based 2026 context ranges, not quotations. Only a contractor who has inspected the property and defined the scope can quote the work; engineering or geotechnical input may also be required.
Two truths from a decade of quoting:
Most jobs land at the small end. The gap between what homeowners fear (“this will be $50k”) and the median real job is enormous. Fear of the number is why people ignore cracks for years — which is the one strategy guaranteed to move a job up this table.
The quote range between contractors is wide. Same job, quotes varying 2–3x, is common — different methods, different overheads, occasionally opportunism.
Polyurethane injection: the slab option worth knowing about
For settled concrete slabs, expanding polyurethane foam injection has become an alternative to traditional underpinning in NZ, and most homeowners don't fully understand it until a contractor mentions it.
It's particularly well suited to voiding or undermining in slabs — where water (a leaking pipe, poor drainage, or repeated flooding) has eroded — or excessive drying has affected — the compacted material or ground beneath, leaving voids. The concrete bridges the gap for a while, then cracks or drops. Resin injection fills those voids and re-supports the slab in one operation — often without needing to lift anything at all. If washout caused it, though, the water problem gets fixed first, or the voids come back.
How it works: small holes (roughly coin-sized) are drilled through the slab in a grid, and an expanding polyurethane foam is injected beneath it. The foam expands, fills voids, compacts the ground, and — with careful staged injection — lifts the slab back toward level, monitored in real time with laser levels.
The generic benefits:
- Speed and disruption: typically hours to a couple of days, versus days-to-weeks of excavation for traditional underpinning. No dig-out, lower mess.
- Consent and approvals: requirements are project-specific. Confirm them with the council and relevant professionals before work starts.
- Precision: lift is applied gradually.
- Cost: often cheaper than excavation-based underpinning for comparable slab problems, though it scales with area and lift.
The honest caveats: it treats the slab and the ground immediately beneath it — sometimes it cannot fix the underlying problem, and if the root cause is drainage or ongoing ground movement, that still needs fixing or the settlement returns. It can be a more short-term fix than structural underpinning, and it's best suited to hardscaped sites where the influence of shrink-swell effects is already low. It's for slabs and strip footings, not really piled timber foundations, and results depend heavily on operator skill and a sound investigation of whythe slab settled. If re-repair is ever needed, foamed ground is harder to excavate and adds soil-tipping costs. And the expanding foam can unintentionally fill voids that didn't need filling — drainage lines especially (particularly Novacoil) — creating a new problem while fixing the old one. It's also not the same thing as epoxy/polyurethane crack injection, which seals cracks in concrete but doesn't re-level anything — quotes sometimes blur the two, so check which one you're being sold.
How to sanity-check a quote
- Is the proposed scope supported? Ask what inspection evidence and assumptions support it, and seek independent professional advice if the explanation is unclear or structural uncertainty remains.
- Posts or just jack studs? On pile work, check whether the scope includes new concreted 125mm posts or only new jack studs — the timber block on top of the concrete block. If only the jack studs are replaced, the original footing is still subject to the same movement, and the settlement can come back. Some contractors level and replace only the jack studs but charge the same price as new concrete foundations.
- Is drainage addressed? If ground water caused the movement and the quote doesn't touch drainage, the problem may return.
- Get the “why”. A good quote explains what's moving, why, and how the fix stops it — not just line items.
- Compare like with like. Method matters: screw piles vs timber, partial vs full, depth, locations and fixings — and are any specialist reports needed to re-affirm the fix?
What makes repairs more expensive
Poor subfloor access (low houses cost more), depth to solid bearing, live-in vs vacant work, sloping sites, and — the big one — waiting. Movement that would have been one corner's underpinning becomes two walls' worth in a few wet winters.