What is the rebuild cost of a house?

The rebuild cost (also called the reinstatement value) is the amount it would cost to completely rebuild your home from scratch if it were destroyed — for example by fire, flood, or subsidence. It is almost always lower than the market value because it excludes the land. Insurers use the rebuild cost to set the "sum insured" on your buildings insurance policy, and under-insurance can trigger the "average clause" and reduce any claim payout proportionally.

How is rebuild cost calculated?

Rebuild cost is calculated by multiplying the internal floor area (in square metres) by a cost per square metre specific to the property type, then adjusting for region, age, and construction. The Building Cost Information Service (BCIS), published by RICS, publishes the canonical UK rates each year. In 2025 the national-average base rate is roughly £1,850–£2,200/m² for flats, £1,700–£2,050/m² for terraces, £1,800–£2,200/m² for semis, and £1,900–£2,400/m² for detached houses. London attracts a 20–40% regional uplift; listed buildings attract a further 30–50% uplift for specialist materials and consents.

Why is London rebuild cost higher?

Inner London carries a regional multiplier of roughly 1.30–1.45× the UK national average because of higher labour rates, site access and logistics constraints, longer prelims (preliminary works), and competition for skilled trades. Outer London sits around 1.15–1.25×. BCIS publishes regional factor tables to reflect this; our calculator uses a postcode-area lookup to apply the correct factor automatically.

Do listed buildings cost more to rebuild?

Yes. A Grade I, II* or II listed building typically adds 30–50% to the base rebuild cost because any replacement must use original-spec materials (lime mortar, hand-made bricks, slate, sash joinery) and be approved by the local authority conservation officer. Specialist trades command a premium. Our calculator applies a midpoint +35% uplift when you tick "listed".

What is the "average clause" on a buildings insurance policy?

The average clause is a standard condition that reduces your claim payout in proportion to how under-insured you are. For example, if your sum insured is £200,000 but the true rebuild cost is £300,000 (67% covered), a £50,000 claim could be settled at £33,000. Keeping your sum insured aligned with the true rebuild cost avoids this — which is why homeowners should review it every year and every time they complete significant works.

How accurate is a rebuild cost calculator?

Calculators like this one give an indicative figure suitable for reviewing your buildings insurance sum insured. They are NOT a substitute for a formal RICS reinstatement valuation, which you should commission if your property is listed, non-standard (thatched, timber-frame, stone), extended, in a flood-risk area, or worth over £1 million. A formal valuation typically costs £200–£600 and is fully tax-deductible for landlords.

Does rebuild cost include outbuildings, garden walls, and drives?

Most buildings insurance policies define "the buildings" as the main dwelling plus permanent outbuildings (garages, sheds on foundations), boundary walls, fences, gates, paved drives, and patios. If you have significant outbuildings, an outdoor pool, tennis court, or a large boundary wall, add their rebuild cost to the calculator output — these items typically add 5–15% to a standard detached house figure.

How often should I review my rebuild cost?

At least every year at renewal, and always after: (1) major works or an extension, (2) a significant change in construction inflation (BCIS reports run at roughly 3–5% per year on average), (3) a material change in regional cost trends, and (4) any change in the building's listed or conservation status.

Rebuild Cost Calculator 2026

Estimate the true rebuild cost of your home using BCIS/ABI 2025 residential reinstatement rates. Regional multipliers for London, South East, Scotland, Wales and beyond — plus uplifts for listed buildings, pre-1919 fabric, and non-standard walls.

Rebuild Cost Calculator

Property type

Internal floor area (m²)

Leave blank to use the average for a semi-detached house (95 m²). You can usually find floor area on the EPC certificate.

Postcode

Used only to apply the correct BCIS regional multiplier. Nothing is stored.

Approximate age of the building

Wall construction

Is the property listed?

Estimated rebuild cost (buildings insurance sum insured)

£171,000 – £209,000

Midpoint £190,000

How this figure was derived

Floor area	95 m² (default)
Base rate (BCIS 2025 national average)	£1,800–£2,200/m²
Regional factor	1.00× (UK national average)
Total multiplier	×1.00

This is an indicative estimate based on BCIS and ABI 2025 residential rebuild guidance. For a figure your insurer will rely on — especially for listed, non-standard, or high-value properties — commission a formal RICS reinstatement valuation. Under-insurance can trigger the "average clause" and reduce any claim proportionally.

What is rebuild cost and why does it matter?

Rebuild cost — also called reinstatement cost or reinstatement value — is the amount it would cost to completely rebuild your home from scratch if it were destroyed. It is always lower than market value because it excludes the land. Your buildings insurance policy uses the rebuild cost to set the sum insured, and keeping that figure accurate is one of the most important things a homeowner can do to protect themselves financially.

Under-insurance is common and punishing. Most policies contain an average clause which reduces any claim payout in proportion to how under-insured you are. If your true rebuild cost is £400,000 but you have insured for £300,000 (75% covered), a £40,000 claim after a burst pipe could be settled at just £30,000. A review every year at renewal — and after any significant works — is the simplest protection.

BCIS 2025 base rates by property type

Our calculator uses the national-average BCIS residential reinstatement rates published in January 2025. These are the industry-standard rates that RICS surveyors and insurers work from. They apply before any regional multiplier or uplift.

Property type	Base rate 2025	Typical size
Flat / apartment (no lift)	£1,850 – £2,200 / m²	~65 m²
Terraced house	£1,700 – £2,050 / m²	~80 m²
Semi-detached	£1,800 – £2,200 / m²	~95 m²
Detached	£1,900 – £2,400 / m²	~130 m²

Source: BCIS Residential Rebuild Cost Index (Jan 2025 rebase, +3.8% year on year) plus independent cost-modelling data published by RICS at TPI 226 (Jul 2025).

Regional multipliers

BCIS publishes regional factors to reflect local labour, materials, and site-access differences. London prime carries the heaviest premium because of labour shortages, prelims, and logistics. Our calculator applies the correct factor automatically from the postcode — here's the full table:

Region	Multiplier	Example areas
Inner London (prime)	1.38×	Westminster, K&C, Camden, W1, SW1, W9
Inner London	1.25×	Hackney, Southwark, Lambeth, E1
Outer London	1.18×	Ealing, Barnet, Bromley, Croydon
Prime SE commuter belt	1.10×	Surrey, KT, GU, SL, HP, St Albans
South East / South West	1.03×	Brighton, Oxford, Bristol, Exeter
Scotland	0.97×	Edinburgh, Glasgow, Aberdeen
North of England	0.95×	Manchester, Leeds, Newcastle
Wales	0.93×	Cardiff, Swansea, Newport
Northern Ireland	0.88×	Belfast

Uplifts explained

Certain building characteristics add materially to rebuild cost because they require specialist materials, trades, or consents. Three uplifts stack on top of the regional figure:

Listed building (+35%) — Grade I, II* and II listed properties require original-spec materials and listed building consent for any works. BCIS/ABI place this uplift in a 30–50% range; the calculator uses the 35% midpoint.
Pre-1919 fabric (+15%) — Victorian and older properties use traditional techniques (lime mortar, solid walls, bespoke joinery) that are slower and more expensive to replicate than modern cavity-wall construction.
Non-standard wall construction (+10%) — stone and timber-frame walls need specialist trades and longer lead times for materials.

Frequently asked questions

What is the rebuild cost of a house?: The rebuild cost (also called the reinstatement value) is the amount it would cost to completely rebuild your home from scratch if it were destroyed — for example by fire, flood, or subsidence. It is almost always lower than the market value because it excludes the land. Insurers use the rebuild cost to set the "sum insured" on your buildings insurance policy, and under-insurance can trigger the "average clause" and reduce any claim payout proportionally.
How is rebuild cost calculated?: Rebuild cost is calculated by multiplying the internal floor area (in square metres) by a cost per square metre specific to the property type, then adjusting for region, age, and construction. The Building Cost Information Service (BCIS), published by RICS, publishes the canonical UK rates each year. In 2025 the national-average base rate is roughly £1,850–£2,200/m² for flats, £1,700–£2,050/m² for terraces, £1,800–£2,200/m² for semis, and £1,900–£2,400/m² for detached houses. London attracts a 20–40% regional uplift; listed buildings attract a further 30–50% uplift for specialist materials and consents.
Why is London rebuild cost higher?: Inner London carries a regional multiplier of roughly 1.30–1.45× the UK national average because of higher labour rates, site access and logistics constraints, longer prelims (preliminary works), and competition for skilled trades. Outer London sits around 1.15–1.25×. BCIS publishes regional factor tables to reflect this; our calculator uses a postcode-area lookup to apply the correct factor automatically.
Do listed buildings cost more to rebuild?: Yes. A Grade I, II* or II listed building typically adds 30–50% to the base rebuild cost because any replacement must use original-spec materials (lime mortar, hand-made bricks, slate, sash joinery) and be approved by the local authority conservation officer. Specialist trades command a premium. Our calculator applies a midpoint +35% uplift when you tick "listed".
What is the "average clause" on a buildings insurance policy?: The average clause is a standard condition that reduces your claim payout in proportion to how under-insured you are. For example, if your sum insured is £200,000 but the true rebuild cost is £300,000 (67% covered), a £50,000 claim could be settled at £33,000. Keeping your sum insured aligned with the true rebuild cost avoids this — which is why homeowners should review it every year and every time they complete significant works.
How accurate is a rebuild cost calculator?: Calculators like this one give an indicative figure suitable for reviewing your buildings insurance sum insured. They are NOT a substitute for a formal RICS reinstatement valuation, which you should commission if your property is listed, non-standard (thatched, timber-frame, stone), extended, in a flood-risk area, or worth over £1 million. A formal valuation typically costs £200–£600 and is fully tax-deductible for landlords.
Does rebuild cost include outbuildings, garden walls, and drives?: Most buildings insurance policies define "the buildings" as the main dwelling plus permanent outbuildings (garages, sheds on foundations), boundary walls, fences, gates, paved drives, and patios. If you have significant outbuildings, an outdoor pool, tennis court, or a large boundary wall, add their rebuild cost to the calculator output — these items typically add 5–15% to a standard detached house figure.
How often should I review my rebuild cost?: At least every year at renewal, and always after: (1) major works or an extension, (2) a significant change in construction inflation (BCIS reports run at roughly 3–5% per year on average), (3) a material change in regional cost trends, and (4) any change in the building's listed or conservation status.

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