Most expensive Grand Designs homes

These spectacular homes are the result of big budgets. Was it money well spent?

By Hugh Metcalf | 10 November 2020

Budget. It’s one of the key drivers of a self build project, but one that many Grand Designers shy away from discussing. But it’s no secret that, over the years, many projects have overrun and overstretched the estimated spend. However, where budgets run high, so does the wow-factor of the finished home. Take a peek at four of the most expensive Grand Designs projects and discover why they cost so much.

Exterior view of the converted Victorian water tower which was one of the most expensive Grand Designs conversion projects.

A glass extension contrasts with the Victorian tower. Photo: Jefferson Smith

The Water Tower, Kennington

Leigh Osborne and Graham Voce undertook a huge project in converting a derelict water tower in London. But their ambitious plans far outstripped their original budget. The glazing alone cost £240,000, and scaffolding hire was £60,000. Within the first half-hour on site, the foundations had gone up by £25,000, after builders realised they would have to dig deeper. Then, £35,000 was spent on a high-tech audio-visual system and £25,000 on an air-source heat pump, which provides hot water and heating.
The couple estimated that they spent £2,000 extra than budgeted every day they spent on site.