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Rebuild cost calculator – how do I calculate the rebuild cost of my home?

Do you know how much it would cost to rebuild your house? Find out how a rebuild cost calculator can help you find a great buildings insurance quote.

Do you know how much it would cost to rebuild your house? Find out how a rebuild cost calculator can help you find a great buildings insurance quote.

Written by
Anna McEntee
Insurance expert
Last Updated
31 JANUARY 2025
4 min read
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What is the rebuild cost of my house?

The rebuild cost is the amount it would cost to cover rebuilding your home, including the fixtures and fittings, if disaster strikes and it’s burned down or destroyed beyond repair.

The rebuild cost is different from the amount that you might be able to sell your home for or its market value. It’s worked out by estimating the costs of the building materials and the labour involved in rebuilding your home.

If your home has special architectural or historical features, is a listed building or is made from non-standard materials, it might cost more to rebuild than its resale value.

How much would it cost to rebuild my house in the UK?

The rebuild cost of your home is the amount of money it would take to rebuild your home to its existing design and specifications, using modern materials and techniques. Costs that will need to be considered include:

  • Demolition
  • Debris clearing
  • Architect fees
  • Planning costs
  • Cost of labour and materials
  • Installation of plumbing, electricity, ventilation and gas
  • Built-in fittings in the kitchen and bathroom

The type of property and location may also need to be factored in. For example, how easy will it be to get construction materials on to site?

You won’t need to consider the cost of loose fittings in the house, such as furniture or possessions. Your contents insurance should cover them.

Using a home rebuild calculator can make estimating the cost of rebuilding your home easier.

How do I calculate the rebuild costs of my house?

You can use a home rebuild cost calculator to calculate the rebuild cost for insurance.

However, depending on the type of house you might need to rebuild, a rebuild cost calculator may not always be the most accurate.

If you recently bought your home

The rebuild cost should be included on your mortgage valuation or deeds. Otherwise, it will depend on whether you live in a:

  • standard brick house with a slate or tile roof
  • home constructed from non-standard materials like wood or concrete
  • historic or listed building
  • flat or maisonette.

If you live in a standard house made of brick or stone

You can use the house rebuild cost calculator from The Building Cost Information Service (BCIS) to work out the cost. BCIS is the main source of residential rebuilding cost data in the UK.

To use the BCIS rebuild cost calculator properly, you should work out your home’s floor area. Sometimes this is on the estate agent’s floorplan when you bought your house or it may be in the survey report.

Alternatively, Compare the Market can help you calculate your house rebuild cost using the BCIS rebuild cost calculator service when you compare buildings insurance.

If you live in a ‘non-standard’ home

A non-standard home is one that isn’t made of standard construction materials, such as brick or stone. Or it’s a historic or listed building.

Homes built using non-standard materials – for example, timber or concrete, or with a thatched roof – are likely to be more complicated and expensive to rebuild.

If you live in a non-standard home, it’s best to get in touch with a professional surveyor. They’ll complete a detailed assessment of your house and provide a professional Rebuilding Cost Assessment. Find out more about types of home survey.

Another option is to find an insurance provider that offers ‘blanket’ coverage of a set amount (£500k, £1m or sometimes unlimited) if you’re really unsure of the rebuild cost. But it’s best to get a professional surveyor’s opinion before you go down this route.

If you live in a listed building, this could also significantly increase the cost of rebuilding your home. To find out if your home is listed and what grade it’s listed as, contact English Heritage, Historic Scotland, Cadw or the Northern Ireland Environment Agency, depending on which area of the UK you live in.

If you live in a leasehold flat

Most flats in the UK are leasehold. If yours is one of them, then it’s the responsibility of the building owner or management company to provide an accurate rebuild cost. They’ll likely pass on some of the cost to you as part of their service charge.

If you live in a freehold flat

You’ll need to calculate the rebuild cost yourself and get the professional opinion of a surveyor. In this case, simply knowing the square footage of your flat won’t predict the rebuild value as it’s likely other parts of the structure will also need to be rebuilt.

Find out more about buildings insurance for flats.

Why do I need to work out the rebuild cost of my home?

Calculating the rebuild cost of your house is an essential part of applying for buildings insurance. This is because you need enough cover to protect yourself if the worst should happen and you need to rebuild your home.

If you don’t work out the rebuild costs, you could end up either over-insured and paying too much for your buildings insurance or underinsured and not able to claim the full cost of rebuilding your home and having to make up the shortfall yourself.

It’s a good idea to recalculate the rebuild costs for insurance when you renew your policy. The cost of building materials and labour has increased substantially recently, so a rebuild calculation from a few years ago may no longer be accurate.

Will the rebuild cost increase if I make changes to my home?

If you decide to add an extension, conservatory or a loft conversion then the rebuild value of your home will increase.

You’ll need to reassess the cost and inform your insurance provider when the work’s complete, otherwise you may be underinsured, and you’ll have to pay the difference in the event of a claim.

Read our guide to how home improvements can affect your home insurance policy.

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Frequently asked questions

What happens if I under or overestimate the rebuild value of my home?

If you underestimate the rebuild cost of your home, any potential insurance pay-out might not be enough to complete the rebuild. You might have to cover the shortfall out of your own pocket.

In the worst-case scenario, underestimating the rebuild cost could invalidate your buildings insurance policy.

If you overestimate the rebuild cost of your home, you could pay more for your monthly premiums than you need to.

Is the rebuild cost different from the market value of my home?

Yes, the rebuild cost is normally lower than the market value of your home.

The rebuild cost doesn’t include the price of the land the building sits on and isn’t affected by other factors that affect housing prices, such as location or supply and demand of homes.

However, the rebuild cost will be affected by the supply, demand and cost of building materials and labour, which can vary across the UK.

What do I need to do to use the rebuild cost calculator?

To use the BCIS rebuild cost calculator, you’ll need to create an account and log in. You’ll then be asked some questions about your home, including:

  • The type of property – detached, terraced or semi-detached?
  • How many floors/storeys your property has
  • Your postcode
  • The year your home was built (or best estimate)
  • The gross external floor area – called the GEFA
  • The number of bedrooms and bathrooms
  • If you have a garage (that’s not included in the GEFA) or a cellar
  • If your walls are brick or stone
  • If the roof is tile, slate, flat or thatched
  • If your home has any special architectural features.

What is my home’s GEFA and how do I calculate it?

The GEFA is your home’s gross external floor area (GEFA). You’ll need to know this to use the rebuild cost calculator.

To work out the GEFA, first measure the external length and width of the ground floor walls in metres or feet. Multiply these numbers together to get the ground floor area.

If the upstairs level – or levels – are the same size, then you can simply multiply the ground floor area by the number of floors. If it’s different, you’ll need to calculate it separately and add the numbers together for a total rebuild figure.

Your total GEFA also includes extensions, integral garages (that you can enter through a door in the house), chimney stacks and conservatories.

But you don’t need to include separate outbuildings such as greenhouses, sheds, parking areas or attached garages.

What counts as a non-standard home?

A non-standard home is one that’s not made of brick or stone with a slate or tile roof. Your home is probably classed as non-standard if it’s made from:

  • Glass
  • Plastic or fibreglass
  • Concrete, asphalt or shingle
  • Metal, including corrugated iron walls or frames
  • Wood, including timber frames
  • Wattle and daub or cob.

Your home will also be classed as non-standard if it’s prefabricated, a barn conversion or has a thatched or flat roof. It may also be non-standard if it has particular types of cladding.

Anna McEntee – Home, travel and pet insurance expert

Anna’s all about delivering fantastic insurance products at a great price. Value is the most important thing for Anna, as she cuts through the jargon and finds what’s most important and worth your hard-earned money.

Learn more about Anna

Andy Webb - Insurance expert

Andy Webb is an award-winning personal finance journalist and broadcaster. Combined, his Be Clever With Your Cash blog, Andy Clever Cash YouTube channel and Cash Chats podcast have been read, watched and listened to by millions.

Learn more about Andy

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