On a construction site public liability stops being a general business cover and becomes a condition of entry. The principal contractor carries duties for the whole site and manages them partly by requiring everybody on it to insure, at a limit the contract names, with evidence held before the first delivery arrives. Understanding which policy answers for what on a site is the difference between a smooth handover and an argument about who pays for the damage.
Public liability insurance for building contractors: who is asking
The requirement comes down the contract chain. A client insists on a limit from the principal contractor, who insists on the same or more from every subcontractor, who insists on it from their own labour only trades. Five million pounds is the common figure on managed sites and ten million appears on larger projects and on anything near rail, utilities or a public highway. The requirement is usually to hold the cover, to name the limit and, sometimes, to note the principal contractor's interest on the policy. The same chain sets public liability insurance for bricklayers, roofers and every other subcontract trade on the site.
Builders liability insurance cost: the limit most builders hold
Simply Business prints builders public liability cover from £7.32 a month: 10% of the builders it insured paid £87.89 a year or less between 1 January and 30 June 2026, for up to £2m of cover, and 80% of those customers hold a £1m limit while 20% hold £2m. Those are domestic limits; the five million pounds a managed site asks for is quoted separately, and worth asking for before the first site contract.
Builders public liability insurance: what does it cover on a site?
It answers for injury and property damage to third parties. It does not pay for damage to the works themselves, which is contract works or contractors' all risks cover; it does not pay for damage to plant you hired, which is hired in plant cover; and it does not pay for injury to your own operatives, which is employers' liability. A site policy assembled from a single liability section will leave the two most expensive site losses uninsured, and both of them are ordinary events rather than disasters.
CDM duties sit beside the policy, not inside it
The Construction (Design and Management) Regulations 2015 allocate duties to clients, principal designers, principal contractors and contractors, and those duties exist whether or not anybody is insured. They matter to insurance in two ways: an insurer will ask how a firm manages site safety, and a claim will be investigated against what the regulations required. Good CDM paperwork is not a policy condition on most wordings, but it is the evidence a defence is built from.
Underground services and the things that catch people out
Striking a buried cable, main or drain is one of the most expensive routine losses in construction, and several trade policies limit or exclude damage to underground services. Working at height, hot works and demolition are each rated and sometimes conditioned separately. A firm that has grown from domestic work into site work should have those four things read back to it from the schedule before the next contract is signed.
Questions people ask about public liability insurance construction
What limit of public liability does a construction site require?
Five million pounds is the usual figure on managed sites, with ten million on larger projects and on work near rail, utilities or public highways. The exact number is in the contract, and the principal contractor will usually want to see the certificate before you go on site.
Is contractors' all risks the same as public liability?
No. Public liability answers for injury and damage to third parties. Contractors' all risks, sometimes called contract works, answers for damage to the works themselves and to materials on site before handover. Most construction firms need both, and they are separate sections.
Do CDM regulations require insurance?
The regulations impose health and safety duties rather than an insurance requirement. The insurance requirement comes from the contract. In practice the two travel together, because contractors use both to manage the same risk.
Does public liability insurance cover contractors working for you?
It can, where they are declared. Labour only subcontractors are usually treated as employees for employers' liability purposes, while bona fide subcontractors carry their own cover. Which category your people fall into changes the premium and the answer at claim, so it is worth settling at quote.
Is there builders public liability insurance for the self employed?
Yes. Simply Business prints builders public liability cover from £7.32 a month for up to £2m of cover, and 80% of the builders it insured hold a £1m limit. A self employed builder going onto a managed site will still be asked for the limit that site's contract names, commonly five million pounds.
Do construction workers need public liability insurance?
On a managed site, yes in practice: the principal contractor requires everybody on it to insure at the limit the contract names, with evidence before work starts. Injury to your own operatives is a separate cover, employers' liability, which public liability does not replace.