The most misleading thing about renovation pricing in London is a single number pretending to be an answer. A full house renovation is quoted as a band, and the band is wide. The width is not vagueness. It is the honest shape of the market, and what puts a project at one end of it or the other is worth more than any headline figure.
What the band actually describes
It covers renovating a whole house end to end. Strip out, services rewired and re-plumbed, walls, floors and ceilings renewed, bathrooms and kitchen replaced, decorated throughout. At the lower end sits work to a durable family standard with sensible specification choices. At the upper end sits deeper intervention: structural alteration, full height joinery, stone, underfloor heating throughout, where the finish itself becomes the project.
The biggest driver is not size but depth, meaning how much of the existing house survives. A renovation that keeps the plan and renews the surfaces sits low in the band. One that moves the stair, opens the rear and re-imagines the plan sits high, because every moved wall drags structure, services and finishes along with it.
Where your own project sits
NU publishes its own rates rather than a market average. The build cost calculator carries every band, by work type and by tier, from a high end refurbishment through to a super prime finish. Reading the tier is the part that matters. A lateral apartment behind a listed facade with full bespoke joinery is not priced off the same line as a family house renovation.
If a builder quotes a figure a long way outside the published band, in either direction, ask what they have assumed. The answer is usually in what has been left out.
How to use the band before you have drawings
Take the internal area, multiply it by both ends of the band for your level of work, and treat the result as the envelope every design decision has to live inside. Done this early, the arithmetic disciplines the design rather than the design shocking the budget.
The other early decision is the route. The architect led and design and build routes distribute risk differently, and on a whole house project the gaps between separate firms are where budgets quietly die.
A loft conversion added to the same programme is usually cheaper than building it as a separate project later. One scaffold, one team, one period of disruption.
One team, one contract, one number
NU Projects is a design and build practice established in 2010. Architecture, interior design, project management and construction sit under a single contract, so the figure you agree is carried by one accountable team from the first drawing to handover.
Send us the address and the internal area, and we will tell you where in the published band the project genuinely sits.
To talk to the team, send two lines through the contact form. You can also call 020 7731 6841. We usually reply within a few hours, weekends included.
Published 25 August 2026. Written by the NU Projects studio, edited since for house style and accuracy.