A Victorian water tower that transformed in to a home

There is a pleasing irony in the fact that the winner of the 2010 Carbuncle Cup (an award for the ugliest new building in the United Kingdom) played a key role in the genesis of a neighbouring and more genuinely celebrated architectural development. For it was from his flat on the upper floors of the much-derided Strata Tower in south London that Leigh Osborne first spotted a comparatively small and crumbling brick structure no more than 400 metres away. 'I wonder what that is,' he said casually to his partner Graham Voce. Graham braced himself.

The ensuing transformation from pigeon-guano-filled, English Heritage-designated 'Building at Risk' to an architectural marvel has been well-documented, thanks to an episode of the television series Grand Designs. Filmed in 2012, it showed presenter Kevin McCloud following the gradual conversion of the Victorian water tower that Leigh had spied from the carbuncle.

It had been built in 1877 to serve the adjacent Lambeth Workhouse, but had remained derelict for decades. Leigh's plan was a radical reimagining: a unique house with just one room on most of its nine floors. 'There were bits falling off it,' he recalls. 'The risk was that it would have been knocked down.' Because the Grade II-listed building tapers towards the top, the lift only reaches the fifth floor, so good knees and determination are needed to reach the summit of the e 30-metre tower. It is worth the effort: each side has windows, creating a sitting room with 360-degree views of London. The couple are particularly popular leading up to New Year's Eve, when the Thameside celebrations can be seen unobstructed.

At the base of the tower, a two-storey, 36-metre-square extension was added; its glass façade apparently has the largest set of sliding glass doors in Europe. The interior decoration, overseen by Sue Timney, is light, modern and laid-back, with comfortable sofas, plenty of rugs from The Rug Company and interesting modern art. It is a grand design indeed.

But leave to one side the 'will they or won't they succeed' drama of the television programme and you have the story of the individuals who turned their grand design into a home once the cameras stopped rolling. Look a little deeper and you will also see how their lives and livelihoods informed their choices. You could say that both Leigh and Graham's jobs both deal with ensuring a future for once-cherished things, although this is manifested in rather different ways.

In the 10 years leading up to the purchase of the water tower, Leigh had bought, refurbished and (mostly) sold 40 properties in London. In part, that is how he was able to take on the project - though pushing the limit on his credit cards helped, too. Leigh seems to be one of those people blessed not only with the gift of seeing potential, but also for developing it. And not only when it comes to property.

Around the time of the water-tower project, Leigh began working one day a week on reception at Chiswick Auctions, co-owned by his friend William Rouse. He loved the environment and had lots of ideas for bringing the already successful auction house to the next level, so when William's former business partner left the company five years later, Leigh purchased his share.

It is fair to say that the outside of the auction house does not give off the same instant visual delight as Leigh's home. Part of a business park with neighbours including builders' merchants and a car-washing service, it's a little rough around the edges, but perfectly fit for purpose. And as is so often the case with off-the-beaten-track destinations, the discovery of something fabulous is all the more satisfying.