What is a rebuild cost?

The rebuild (reinstatement) cost is what it would cost to demolish, clear and rebuild the property to its current specification, including professional fees and site clearance. It is not the market value and it is not the purchase price.

Is a rebuild cost calculator accurate enough for insurance?

A calculator gives an indicative figure for standard construction. Listed buildings, non-standard construction, unusual sites and high-value or commercial properties should be assessed by a RICS surveyor or a BCIS-based valuation.

What happens if the sum insured is too low?

Underinsurance can trigger average, so a claim payment is reduced in the same proportion as the shortfall. A property insured for half its rebuild cost can see a claim settled at around half its value.

Free · No sign-up · UK figures

Rebuild cost calculator for UK buildings sums insured

Get an indicative reinstatement cost from floor area, property type and region — the figure you need for the buildings sum insured, not the market value.

Gross internal floor area (m²)

Measure inside the external walls, across every storey. 1 m² = 10.76 ft².

Property type

Region

Build rate override (£ per m²) — optional

Drop in your own BCIS or surveyor rate if you have one — it replaces the default.

AdjustmentsDetached garage or outbuildingBasement or below-ground levelListed or heritage construction

Indicative rebuild cost

£316,109

Working range £284,498 – £347,720

Construction: £282,240
Fees, clearance & debris removal (12%): £33,869

Read this before you use the figure

This is an indicative estimate for standard construction, produced from average UK build rates and a regional factor. It is not a valuation and it is not a substitute for a RICS or BCIS assessment. Listed buildings, non-standard construction, unusual sites, and larger commercial risks should be professionally assessed before you set a sum insured.

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Rebuild cost is not market value

The rebuild cost is what it would take to clear the site and put the building back as it stands, with professional fees and debris removal on top. The land is already there, so in much of the country the rebuild figure sits below the sale price — and in some areas well above it. Insuring on the purchase price is the single most common cause of a wrong buildings sum insured.

How underinsurance bites at claim stage

Most UK buildings policies apply average. If the declared sum insured is 60% of the true rebuild cost, a partial loss can be settled at 60% of the claim. The client feels that shortfall at the worst possible moment, and the conversation lands on the broker's desk. Reviewing the figure at every renewal — and recording that you did — is the cheapest protection available.

What this calculator includes

Construction cost based on floor area, property type and a regional cost factor.
Allowances for a detached garage or outbuilding and for below-ground space.
An uplift for listed or heritage construction, where materials and methods cost more.
12% for professional fees, site clearance and debris removal.

It does not include contents, stock, machinery, loss of rent, alternative accommodation, or the cost of complying with local authority requirements on a rebuild. Add those separately.

More free broker resources

Working templates and plain-English walkthroughs for the paperwork brokers produce most often:

Broker guides & templates Demands & needs statement template Claim notification letter template