A quotation can look thorough, a builder can come recommended and a project can be carefully planned – but are building works insured if something goes wrong halfway through? It is one of the most sensible questions a homeowner can ask before an extension, renovation or structural alteration begins.
Insurance does not remove every risk from a building project. What it should do is make clear who carries the financial responsibility if accidental damage, injury, theft or an unexpected event affects the work. The answer depends on the contractor’s policies, your own home insurance and the type of project being carried out.
Are building works insured by the contractor?
A professional building contractor should hold insurance suited to the work they undertake. However, the phrase “fully insured” is not enough on its own. Cover has limits, exclusions and conditions, so it is reasonable to ask what policies are in place and request confirmation before work starts.
For most domestic projects, public liability insurance is the starting point. This is designed to cover accidental injury to a third party or accidental damage to their property caused in connection with the contractor’s work. For example, if a member of the team accidentally damages a neighbour’s car while delivering materials, or a visitor is injured because of an unsafe site condition, public liability cover may respond.
Employers’ liability insurance is also a key protection where a contractor employs people. It covers claims from employees who are injured or become ill as a result of their work. It is generally a legal requirement for UK employers, although limited exceptions can apply. Homeowners should not assume that every person on site is an employee, so a contractor’s working arrangements and insurance should be properly managed.
For larger projects, particularly extensions, loft conversions and substantial refurbishments, contractors may also hold contract works insurance. Sometimes called contractors’ all risks cover, this can protect the work in progress, materials and temporary works against insured events such as fire, flood, storm damage or theft. The exact scope varies considerably between policies.
Your home insurance may need updating
Many homeowners assume their buildings insurance will automatically cover an extension or renovation. That can be a costly assumption. Standard policies often expect you to tell the insurer before major works begin, especially when the property will be altered structurally, left unoccupied for periods, or have a roof removed or opened up.
An insurer may continue cover without changes, add conditions, increase the premium or exclude certain risks during the works. In some cases, they may advise a specialist renovation policy instead. The right route depends on the scale of the project, its value and whether you remain living in the property.
Call your insurer as soon as the scope is clear, rather than waiting until the team is on site. Explain whether you are having an extension, internal structural work, a new kitchen or bathroom, roof work, or a full refurbishment. Confirm the expected start and finish dates, the contract value and whether the house will be occupied.
Ask directly whether the existing policy covers the original structure while work is underway, the new works and materials, escape of water, theft from site and any period when the home is empty. Keep the insurer’s response in writing. A short phone call recorded on a policy note can prevent a great deal of uncertainty later.
The difference between insured damage and poor workmanship
This distinction matters. Insurance is not a substitute for choosing a capable contractor, agreeing a clear scope of works and maintaining good site control.
A contractor’s public liability policy may cover accidental damage caused to your existing property, but it does not usually pay simply because work was carried out poorly or a finish does not meet the agreed standard. Similarly, contract works insurance may cover storm damage to a partly completed extension, but it will not necessarily pay to correct defective workmanship or unsuitable materials.
That is why the contract, specification and payment schedule matter alongside insurance. They set out what is being built, the standard expected, who is responsible for ordering materials, how changes are agreed and what happens if a defect is identified. A dependable contractor will discuss these practical details openly rather than treating insurance as a vague reassurance.
If your project includes design input, structural calculations or architectural services, it is also worth asking who holds responsibility for those elements. Professional indemnity insurance may be relevant where a contractor or designer provides professional advice or design work. Responsibilities can differ where drawings are supplied by an independent architect, engineer or designer.
What to ask before building work begins
The most useful approach is straightforward: ask for evidence of the relevant insurance and check that it matches your project. You do not need to become an insurance expert, but you should understand the basics.
Confirm the insurer, policy type, expiry date and level of public liability cover. Ask whether subcontractors are covered or expected to maintain their own policies. For an extension or major renovation, ask whether contract works cover is in place and whether it includes materials already delivered to site.
You should also establish who is responsible for insuring existing parts of the house. If a kitchen renovation is taking place within an occupied home, this may remain principally with your buildings insurer. If a large rear extension is being built, responsibility for the new work and materials may sit with the contractor’s contract works policy until practical completion. The contract should make this clear.
It is sensible to check whether there is an excess – the amount payable before insurance responds – and whether there are value limits that could be relevant to your project. A low policy limit may be less reassuring on a high-value structural alteration than it first appears.
Insurance and work affecting neighbours
Extensions, loft conversions and structural work can affect adjoining homes even when everyone takes care. Scaffolding, access, excavation, deliveries and temporary exposure to weather all need careful planning.
Public liability cover is relevant if the contractor accidentally causes damage to a neighbour’s property. But insurance does not replace good communication or the legal processes that may be needed for certain works. If your project involves a shared wall, excavation close to a neighbouring building or structural work affecting an adjoining property, party wall matters should be addressed before work begins.
Photographic records of existing boundaries, walls and access areas are useful, particularly where properties are close together. They create a clear starting point and can help avoid disputes over whether a crack, mark or damaged surface existed before the project.
When extra cover is worth considering
The bigger and more complex the project, the more closely insurance arrangements should be reviewed. A straightforward bathroom replacement is very different from a whole-house refurbishment involving steelwork, a roof alteration and temporary relocation.
Specialist renovation insurance can be worth discussing with an insurer or broker where the home will be unoccupied, the structure will be significantly altered or the project value is high. It may combine cover for the existing building, the works, materials and liability in one policy. Whether it is necessary depends on the terms of your existing policy and the cover held by the contractor.
Do not confuse insurance with warranties or guarantees. A workmanship guarantee is a contractor’s promise to rectify qualifying defects within a stated period. A manufacturer’s guarantee may apply to a boiler, roof product, window or appliance. Insurance addresses specified insured events; guarantees address different obligations. Both can be valuable, but neither automatically replaces the other.
A clear conversation builds confidence
Insurance should be discussed before the first delivery arrives, not after a problem occurs. A good contractor will be comfortable explaining their cover, their approach to site safety and how responsibility is handled throughout the project. At Primary Construction, clear communication is part of treating every home with the care it deserves.
Take a little time to notify your own insurer, check the contractor’s documents and ensure the written agreement reflects what has been discussed. That preparation lets everyone focus on the more rewarding part of the project: seeing your home take shape with confidence.
