Rebuild cost for insurance.

Property reinstatement value is the cost to rebuild a building from scratch after total destruction. It's the number that should be used for buildings insurance cover - not market value, not mortgage balance. Typical formula: gross internal area × rebuild rate per sqm + demolition costs + professional fees (architect, surveyor, planning).

180 sqm property × 2,200/sqm rebuild rate = 396,000 base cost. + 8% demolition (31,680) = 427,680. + 12% professional fees on total = 51,322. Total reinstatement value 479,002. Typical 3-bed semi figure. Note market value might be 550,000+ including land (land doesn't burn); rebuild is lower because land is preserved.

Under-insuring on reinstatement triggers averaging clauses. If your cover is 70% of reinstatement and you claim, insurer may only pay 70% of the claim amount - so a 50k kitchen fire might only get 35k paid. RICS rebuild cost assessments (RCAs) provide authoritative figures - typically 300-700 depending on complexity, refreshed every 5-10 years.

Run it with sensible defaults

Using gross internal area of 180, rebuild rate per sqm of 2,200, demolition factor of 8%, professional fees of 12%, the calculation works out to 479,001.60. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Gross Internal Area (sqm), Rebuild Rate per sqm, Demolition Factor %, and Professional Fees % — do not pull with equal force. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

How the math works

Base = area × rate. Demolition = base × demolition %. Fees = (base + demolition) × fees %. Total = base + demolition + fees. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

What to do with a low result

A disappointing result is information, not a judgement. Pick the single input that dragged the figure down most and focus the next quarter on that one factor. Breadth-first improvement rarely works; depth-first on the worst input usually does.

What this doesn't capture

The score is a composite of the inputs you provide. Life context — job security, family obligations, health, housing — doesn't appear in the math but shapes the real picture. Use the number as a prompt, not a verdict.