What’s seven storeys tall, 11ft wide and was named the ‘Best New Clerkenwell Building’ at the London Architecture Biennale in 2004? Answer: this striking contemporary townhouse, which has just come on the market. When it was built by architect Jo Hagen, it also won first prize in the RIBA ‘Future House London’ competition and was crowned one of the ‘Top 10 Modern Buildings’ by the Independent. Given the home’s compelling design and ingenious use of space, it’s easy to see why it’s a triumph…

If you weren’t to look up, we’d forgive you for walking right past this soaring steel-and-glass structure on Golden Lane, which is situated (rather ideally, we think) around the corner from the Barbican. Its façade is somewhat hidden for privacy behind a cleverly planted silver birch tree and is sandwiched between two sizable Victorian warehouses. Catch the intriguing double-height front door, however, and you might feel inclined to draw your eyes towards the clouds and take in its tall form inspired by skyscrapers in the City (which residents can view from its own rooftop terrace).

Its site was once home to a dingy disused cab office – but when the architect stumbled across the one-storey building, he saw its potential and snapped it up. As for the concept? “It wasn’t a eureka moment,” Jo told the Independent. “I was constantly thinking about what could be done with it. You have to look for unusual situations and see things where others don’t to get a bargain in London.” When he landed on his final idea, however, it resonated with the client: a growing family who wanted their home to push boundaries while being child-friendly.

Fast-forward to today and the house – which took 18 months to build – is an inner-city jewel. The interiors are both sleek and utilitarian, featuring steel balustrades and open-tread zig-zag staircases – as well as a handy lift for when your legs tire. There are polished limestone floors and textured Venetian plastered walls, while street-facing floor-to-ceiling windows on every level (note the frosted glazing on the first three that provide privacy) allow natural light to pour in. And, in spite of its compact footprint, the clever layout, in which each level (measuring 1,922sq ft) is dedicated to one room only, ensures there’s plenty of breathing space – not least on that rooftop, where you can sit and watch the city go by.