Building an extension is an exciting project (that can add space, comfort and value to your property). But before the building work starts it’s essential to understand your insurance responsibilities. In particular you need to get cover in place before any extension work begins. From protecting the existing structure to covering the works in progress having the right extension insurance in place will give you peace of mind throughout the project.
In this guide we explain what home extension insurance is, what it covers and what additional cover you may need. Whether you’re hiring a builder or managing the work yourself this article will help you stay informed and insured for any building project involving an extension.
What Is Extension Insurance?
Extension insurance refers to specialist cover that protects your home and the new works being carried out during a building extension. Many standard home insurance policies don’t provide adequate cover during building work, particularly for structural alterations, excavation or if the property is unoccupied at any point. Standard buildings insurance also may not cover extension works, leaving gaps in cover for new structures or risks during construction.
Instead a renovation or construction insurance policy is usually required. These policies are designed to cover the risks involved in major home improvement projects such as fire, flood, theft of materials, structural damage or injury to contractors on site. Note a contractor’s insurance policy may not cover all the risks involved in building an extension so additional specialist insurance may be needed for full cover.
Types of Extensions and Insurance
When planning a building extension it’s important to recognise that different types of extensions have their own unique insurance considerations. Whether you’re adding a rear, side or front extension, converting a loft or excavating a basement each project will impact the existing structure in different ways.
For example a rear extension may involve removing load bearing walls or significant structural work, increasing the risk of accidental damage to your home. Loft conversions and basement extensions often require specialist renovation insurance to ensure both the existing building and the new works are fully covered throughout the project.
To protect your investment you need to have the right extension insurance cover in place. Home renovation insurance can provide full cover for the entire project including the existing structure, new extension and building materials. This type of building extension insurance is designed to cover specific risks associated with extensions such as theft, fire, flood and accidental damage during construction.
Will my current home insurance cover my extension?
This is one of the most common questions we get asked. In most cases the answer is no (or at least not fully). Standard home insurance policies have exclusions for building work especially when it involves:
- Structural changes or excavations
- Scaffolding
- Roof alterations
- Increased fire or flood risk
- Periods when the property is unoccupied
Minor cosmetic changes such as painting or decorating don’t require notification to your insurer. However major extension works do.
If you fail to notify your insurer about the planned works your existing policy could be invalidated. That means any claim (even unrelated to the extension) could be denied.
Why You Need Specialist Home Extension Insurance
There are several reasons why having dedicated insurance for building an extension is important:
- Protecting the existing structure: Building work can damage parts of your home not involved in the project.
- Covering the new works: The extension itself (known as “contract works”) needs protection from theft, fire, flood and more.
- Public liability: If a passer-by is injured due to the building work you may be held responsible. This is where public liability insurance (such as public liability insurance) is essential to protect against claims for injury or property damage.
- Employers’ liability: If you hire contractors directly you may need this cover if they are injured on site.
- Alternative accommodation: If your home becomes uninhabitable due to the works some policies cover the cost of temporary housing.
Most contractors have some form of insurance but it may not cover all the risks involved with your extension.
Builders Insurance for Extensions: Who Covers What?
If you’re working with a builder or contractor you might assume their insurance will cover everything. But it’s not always that simple.
Builders insurance for extension projects usually includes public liability insurance, employers’ liability and sometimes contract works insurance. However their policy is designed to protect them, not you or your home.
Key limitations of relying solely on the builder’s insurance:
- It may not cover damage to your existing property
- It may not cover theft of your materials or tools stored on site
- It won’t include cover for delays, abandonment or defective workmanship
That’s why you need to take out your own home extension insurance which fills in the gaps and provides full cover.## Types of Cover
When you get extension insurance you should cover:
- Existing structure: Your home in case it gets damaged during the build
- Contract works: The new extension as it’s being built
- Public liability: Injury to third parties or damage to neighbour’s properties
- Employers’ liability: Cover for tradespeople you hire directly
- Plant and tools: Equipment and machinery used during the works
- Non-negligent liability: Damage caused by contractors but without fault (e.g. vibrations affecting neighbour’s properties)
- Alternative accommodation: If the build makes your home uninhabitable
You may also need extra cover for specific risks, such as theft of building materials or accidental damage during the project. These can be added temporarily for the duration of the works.
If your extension is part of a larger renovation you may also want to look into a renovation insurance policy.
Self-Managed Extension Projects
Are you managing the extension yourself? If so you will be treated as the main contractor by insurers. This increases your liability and responsibility especially if you are hiring subcontractors or tradespeople.
In this case you will need:
- Employers’ liability (a legal requirement if you hire anyone)
- Public liability
- Contract works insurance
- Possibly project manager insurance depending on your role
You must pay for comprehensive insurance to protect yourself from unexpected costs that can arise during a self-managed project. Always be honest about your level of involvement when applying for cover so your policy can be accurately underwritten.
Do You Need Structural Defect Insurance for Extensions?
Structural defect insurance (also known as latent defects warranty) is a separate policy that covers the completed extension against defects that become apparent after the work is finished.
While not required for most domestic extensions it can be a good idea if:
- The work involves significant structural changes (e.g. major alterations to load-bearing walls or foundations)
- You plan to sell the property within 10 years
- You want extra peace of mind against faulty design or materials
Some mortgage lenders or buyers may ask for this type of cover especially for larger or more complex extensions.
Home Insurance When Extension Is Being Built: Do’s and Don’ts
Do:
- Notify your existing home insurer before work starts
- Get written confirmation of whether cover will remain valid
- Keep your home fully insured throughout the project
- Get specialist home extension insurance if your current policy excludes building work
- Ask your builder for their insurance certificates
- Keep records of contracts, payments and plans for insurance purposes
Don’t:
- Assume your current policy will cover everything
- Wait until the work starts before getting cover
- Overlook unoccupied periods (even a few days away could invalidate standard cover)
- Forget to reassess your home insurance value after the extension is complete
Cost of Extension Insurance
The cost of extension insurance will depend on:
- Type of extension
- Value of the project
- Level of cover required
Home insurance providers will give you a bespoke quote taking into account whether you’re self-building or hiring a contractor, and the complexity and duration of the works. Projects involving structural changes or high value materials may result in higher premiums as the risk increases.
Also consider temporary accommodation if your home becomes uninhabitable. These should be factored into your overall budget. Shop around and compare quotes to get the best deal.
When to Get Insurance
Getting insurance before any building work starts is essential. Most providers need advance notice of planned works and if you don’t notify them you could be left without cover if something goes wrong.
Contact your provider during the planning stage to:
- Discuss the specifics of your extension
- Get a quote
- Protect your home from accidental damage or theft during the works
Having insurance in place from day one gives you peace of mind and protects your property from start to finish.
Telling Your Insurance Provider About the Extension
Notifying your home insurer is a crucial step in keeping your property protected. If you don’t tell them you risk invalidating your policy.
Be prepared to provide:
- Type of work being done
- Value of the project
- Completion date
- Builder’s insurance certificates (if applicable)
Provide full and accurate information so your cover remains valid throughout the extension process.
Claims and Extensions
If you need to make a claim during your extension project having the right cover in place is vital. Comprehensive insurance covers both the existing building and the new works.
When making a claim provide your insurer with:
- Full information
- Photographs and documentation
- Witness statements (if applicable)Use a specialist like Hiscox and it will all be much simpler. Their claims teams are experienced in renovation and extension claims so you’ll get a quick resolution and minimal disruption.
What Happens After the Work Is Finished?
Once your extension is complete you should:
- Reassess your home’s rebuild value and contents value
- Update your home insurance policy to reflect the increased size and value
- Cancel temporary policies if no longer needed
- Consider structural defect insurance (if not already in place)
These steps will keep your property insured in the long term.
Don’t Forget Insurance When Extending Your Home
Extending your home is a big investment. Insurance might not be the most exciting part of your project but it’s one of the most important. Whether you’re using a contractor or managing the project yourself having the right home extension insurance will protect you from the unexpected.
At Haden Welbeck we specialise in extension insurance for homeowners, investors and self-builders. We’ll explain your obligations, help you choose the right level of cover and stay protected from day one of your build.
Need Advice on Extension Insurance?
Talk to our renovation insurance brokers today about:
- Insurance for building an extension
- Self-managed projects
- Builders insurance gaps
- Structural defect insurance options
We’ll help you protect your property, your project and your peace of mind.
Call us today or request a quote online
