UK building cost guides

See how real project choices move an early building budget.

Each guide compares three contrasting scenarios calculated from Proper Job pricing model v15. The ranges are examples, with the scope and uncertainty kept visible.

Current model-backed guides

House extension£65,000–£132,000Loft conversion£56,000–£134,000Kitchen renovation£18,000–£43,000Bathroom renovation£11,000–£18,000

Examples help you learn. Your own inputs make the range useful.

These pages use different locations, sizes and scope choices to show why one national average is rarely enough. They are not completed customer projects, quotations or promises of a local price.

Proper Job can use your outward postcode, job type, approximate area, finish, access and likely associated work to calculate a free Guide Price. It returns the assumptions, exclusions and decisions still to confirm with the range.

Calculate my free Guide PriceRead the calculation method

Examples checked 9 September 2026. New guides are added only when they cover a distinct, useful project question.