Once you know screw piles are an option for underpinning, the next question is usually how the cost compares to traditional concrete underpinning. The honest answer is that it depends on the job, but the factors that push the comparison one way or the other are consistent enough to explain.
Where screw piles can cost less
Faster installation. Screw piles are installed mechanically, without excavation, formwork, or a concrete curing period. On jobs where time on site is a major cost driver, that can bring the overall price down.
Less site disruption. No spoil removal and a smaller footprint of works can reduce ancillary costs, particularly on tight or awkward sites where excavation and spoil haulage would otherwise add significantly to the job.
Immediate load-bearing. Because screw piles can generally take load as soon as they’re installed and verified, there’s no waiting period before the next stage of work can proceed, which can shorten the overall program and reduce costs tied to time.
Where the cost can be comparable, or where concrete wins
Shallow rock. Where rock sits close to the surface, a bored pier is generally the more reliable and cost-effective option. Screw piles may need pre-drilling in these conditions, which adds cost and can close the gap with concrete or reverse it.
Very large point counts. For jobs requiring a high number of underpinning points, material and equipment costs scale differently between the two methods, and the comparison should be assessed on a job-by-job basis rather than assumed.
Simple, accessible sites with stable ground. Where a site has good access and straightforward soil, concrete underpinning can be delivered efficiently, and the cost difference between the two methods may be minor.
Why a general figure isn’t useful
Cost comparisons between screw piles and concrete depend on soil conditions, number of points, site access, and the extent of existing damage, the same factors that drive underpinning cost generally. A number that applies to one house’s underpinning job won’t necessarily apply to the next, even on the same street. The comparison that matters is the one done against your specific site.
The point
Screw piles aren’t automatically cheaper or more expensive than concrete underpinning. They tend to have an advantage where speed, access, and disruption matter most, and less of one where ground conditions already favour a bored pier. The way to know which applies to your house is a site assessment, not a rule of thumb.
