Most builders can produce an insurance certificate. Far fewer can explain what it actually covers, what it excludes, or whether it matches the contracts they are signing. That gap is where claims get rejected, tenders get lost, and businesses get exposed.
Builders insurance is not one product. It is a bundle of separate covers, some legally required, most commercially required, all working together to protect the business, the staff, the tools, and the work itself. This guide sets out exactly what a UK builder needs, why, and at what level. It is written for sole traders, small firms, and established contractors who want to get their cover right rather than just cheap.
What Builders Insurance Actually Means
When a client, main contractor, or local authority asks a builder to “prove you’re insured”, they are rarely asking about one policy. They usually want to see several: employers’ liability if there are staff, public liability at a specific limit, and often contract works cover matched to the project value.
The right combination depends on three things: whether the business employs anyone, the type of work being done, and the terms of the contracts being signed. A sole trader fitting kitchens has different needs to a general contractor bidding for a JCT-managed extension.
The rest of this guide walks through each cover, what it does, and when a builder needs it.
Employers’ Liability the One Cover You Legally Must Have
Employers’ liability insurance is the only cover a UK builder is legally required to hold under the Employers’ Liability (Compulsory Insurance) Act 1969. If the business employs anyone other than close family members in an unincorporated setup, it is compulsory.
The legal minimum indemnity is £5 million. Most insurers offer £10 million as standard, and that is what most contractors carry. The policy pays out if a member of staff is injured or made ill through their work and successfully claims against the business.
The penalties for non-compliance are significant. The Health and Safety Executive can fine an uninsured employer up to £2,500 for every day without cover, and a further £1,000 for failing to display the certificate or produce it when asked.
The Control Test and Why Subcontractors Trip Builders Up
The most common way builders end up uninsured without realising is by misclassifying subcontractors.
The test insurers apply is not about tax status. It is about control. A labour-only subcontractor who uses the builder’s tools, follows the builder’s direct instruction, and works under the builder’s supervision usually counts as an employee for insurance purposes. Even if they invoice for their time. Even if they are registered self-employed.
A bona fide subcontractor who brings their own tools, works to their own methods, and carries their own insurance sits outside that test. In practice, verify their certificate before they start.
If a labour-only subbie is injured on site and the builder has no employers’ liability cover in place, the fine is the least of the problem. The claim itself falls on the business.
Public Liability the Cover Every Client Expects
Public liability is not legally required. Almost no client, main contractor, or local authority will let a builder on site without it.
The policy covers injury to third parties and damage to third-party property caused by the builder’s work. A brick falling and cracking a neighbour’s conservatory. A member of the public tripping over site materials. A flood in a client’s flat because a pipe was left uncapped.
How Much Public Liability Cover Do You Need
The £1 million policies advertised on comparison sites are rarely enough to win real contracts.
- £2 million was the historic default and still appears on smaller domestic jobs, but it is slipping behind tender expectations
- £5 million is increasingly the minimum for local authority work and main contractor sub-packages
- £10 million is standard on larger commercial and high-value residential projects
Carrying too little cover is not just a claims risk. It stops the business from bidding. Builders who have held £2 million for years are increasingly finding themselves excluded from tenders they used to win.
What Public Liability Does Not Cover
Three gaps catch builders out regularly:
- Damage to the work the builder is doing. That is contract works.
- The builder’s own tools and equipment. That is plant and tools cover.
- Injury to the builder’s own staff. That is employers’ liability.
Public liability is a third-party policy. Anything the builder owns, employs, or is currently building sits outside it.
Contract Works Insurance for the Build Itself
Contract works insurance, also called contractors’ all risks, covers the work-in-progress. Fire, theft, flood, storm, vandalism, and accidental damage before the project is handed over.
A part-built extension is not covered by the homeowner’s buildings insurance and not covered by the builder’s public liability. Without contract works cover, if that extension burns down two weeks before completion, the cost of rebuilding falls somewhere between the builder and the client, and the argument about which of them usually ends up in court.
When You Need It and Who Should Arrange It
Under JCT contracts, insurance responsibility is split between the employer and the contractor depending on which insurance option applies. Options A, B, and C in the standard JCT forms each place the duty on a different party. Getting this wrong at contract stage creates a real gap.
For renovation work, the existing structure often needs to be insured separately, sometimes by the homeowner under an extended policy, sometimes by the contractor. Read the contract before assuming.
The sum insured should match the full contract value including materials, labour, and professional fees, not just the cost of materials on site.
Plant and Tools Cover Protecting Your Kit
Tools are one of the biggest exposures on a UK building business. Over half of UK builders have had tools stolen at some point, and industry data puts direct tool theft losses at around £40 million in 2024. Wider construction theft now exceeds £1 billion a year.
Plant and tools cover can be standalone or bolted onto a package policy. It typically covers:
- Owned hand tools and power tools
- Hired-in tools
- Small site plant
Common Exclusions to Watch For
The claims that get rejected are almost always about exclusions builders never read:
- Tools left in unattended vehicles. Most policies require a locked hard-sided compartment, an alarm, and often overnight storage away from the vehicle
- Tools left on site overnight without a secure lock-up
- Single-item limits that cap the payout on the most expensive kit, so a £3,000 laser level might only attract a £500 payout under a general schedule
The fix is to declare high-value items individually and check the security conditions before, not after, a break-in.
The Extra Covers Worth Considering
Not every builder needs everything below, but each one matters for a specific type of work.
Professional Indemnity for Design and Build Work
Professional indemnity covers claims arising from professional advice or design work. Any builder who takes on design-and-build contracts, or who gives design input on a project, has professional indemnity exposure.
It is a claims-made policy, which means it responds to claims made during the policy period, not incidents that happened during it. That makes run-off cover important when the business closes or stops doing design work, because claims can surface years after a project ends.
Personal Accident Cover
Personal accident cover pays out if the builder is injured and cannot work. For a sole trader with no sick pay and no salary from anywhere else, an injury that stops them working for three months can end the business.
Hired-In Plant Cover
Standard plant hire agreements make the hirer responsible for the full replacement value of the equipment during the hire period. Hired-in plant cover picks up that contractual liability. Without it, a stolen or damaged excavator becomes a personal cost.
How Much Should Builders Insurance Cost?
Costs vary widely by trade, turnover, staff numbers, claims history, and the cover limits chosen. A sole trader with public liability only sits at the lower end. A small firm carrying employers’ liability, public liability, tools, and contract works sits considerably higher.
Published averages age quickly and rarely reflect the risk profile of a specific business. The only way to get a meaningful figure is a proper quote based on actual turnover, trade activities, and contract requirements.
Common Mistakes Builders Make with Their Cover
The pattern of avoidable errors is remarkably consistent:
- Buying the cheapest £1 million public liability policy, then finding it excludes them from £5 million tenders
- Not declaring all trades or activities on the policy, which can invalidate cover at the point of claim
- Assuming public liability covers damage to their own work
- Letting professional indemnity lapse after finishing a design job, leaving no run-off protection
- Treating the certificate as the whole policy without reading exclusions and endorsements
- Misclassifying labour-only subbies as fully self-employed and skipping employers’ liability
Most of these mistakes only surface when a claim happens or a tender is refused. By then, it is too late to fix.
Getting the Right Cover in Place
The cheapest package is almost never the right package for a builder taking on real contracts. Comparison-site policies are built for simplicity, not for construction risk.
A specialist construction broker knows what main contractors, local authorities, and JCT contracts are actually asking for, and can match cover to the real exposure of the business. That includes advising on indemnity limits, checking exclusions against typical site conditions, and making sure the sums insured on contract works match project values.
Construction Insure has spent over 30 years arranging cover for UK builders, from sole traders to established contractors, across every trade and project type. If your current cover was bought on price rather than fit, it is worth a review before the next big job.
The Cover Sheet Every Builder Should Be Able to Produce
Before the next tender, main contractor onboarding, or client conversation, a builder should be able to produce the following without hunting through a folder:
- Employers’ liability certificate at £10 million (or £5 million minimum) if there are any staff or labour-only subbies
- Public liability certificate at the level the contract requires, typically £5 million or £10 million
- Contract works schedule matched to the current project value
- Plant and tools schedule listing high-value items separately
- Professional indemnity certificate if any design or design-and-build work is involved
If any of those are missing, unclear, or set at the wrong limit, the business is either exposed to a claim or shut out of a contract. Both are fixable, but only in advance.
FAQs
Is builders insurance a legal requirement in the UK?
Only employers’ liability is a legal requirement, and only if the business employs anyone other than close family in an unincorporated setup. Everything else, public liability, contract works, tools cover, is commercially required rather than legally required, but almost every client and main contractor will insist on it.
Do I need employers’ liability if my only worker is a labour-only subcontractor?
Almost certainly yes. If the subbie uses your tools, follows your instruction, and works under your supervision, they count as an employee under the control test that insurers apply. HMRC status does not override that.
Does public liability cover damage to the work I’m building?
No. Public liability covers damage to third-party property, not to the project the builder is working on. Damage to the work-in-progress needs contract works or contractors’ all risks cover.
How much public liability cover do I need to win tenders?
For domestic work, £2 million is often the minimum. For local authority work and main contractor sub-packages, £5 million is now standard. For larger commercial projects, £10 million is common. Check the tender documents before renewal, not after.
Are my tools covered if they’re stolen from my van overnight?
Only if the policy specifically allows for unattended vehicle theft, and only if the vehicle meets the security conditions in the policy. That usually means a locked hard-sided compartment, an alarm, and often overnight storage away from the vehicle. Many policies exclude vehicle theft entirely, so check before assuming.