What price a view of the Gherkin in one direction and Canary Wharf in the other, from a beautifully finished teak deck, high up among the pepper-potted, red-pantile Georgian roofscape of Whitechapel?
This is the sensational view from independent financial adviser Mark Ford's new glass box, miraculously perched on top of a once grim and derelict Victorian corner building, in an area that was until recently the "cockney sparrer" of east London but is now pulling itself up by its bootstraps, helped by the swathe of regeneration going on in this routeway to the Olympic village.
Below Mark's duplex, as part of the same development, is another flat, while at street level there's a streamlined architect's office that is all big window and glowing, hand-cleaned orangey-red bricks.
Mark came here by accident. He had been living in a penthouse in Covent Garden, having also lived in Ladbroke Grove in west London. In the late Nineties, he met Tim Whittaker, who now runs the Spitalfields Trust. Several years later, Tim led a plan to save a group of 10 derelict Georgian cottages from demolition.
The London Development Agency owned them, and if Tim wanted to save them, he had to find £3 million. He got together a group of people keen to restore them under the Spitalfields Trust's guidance. However, as Mark says: "Three quarters of them couldn't get the finance together," [financing derelict houses is more complicated than straightforward mortgages] "so I facilitated that."
Mark's building is on the corner. "This wasn't really in the sale, but the LDA didn't want the deal to go through unless it was bought, too. So Tim wanted me to buy it. I refused. I really didn't want to. It was the ugliest building in the street. Plastic windows, dowdy brickwork. It was revolting, and unloved. And I said that I wanted to live in a glass box. Then Tim said, 'What about if I can get you planning permission for a glass box?'
"I never thought he would, so I agreed." Mark grins. "But then he did." Having agreed to buy it, Mark still had to find the money. "Not many people have half a million kicking around," he points out. He had to go to sealed bids, and bought it for £451,279. The £279 was a whim, but it closed the deal.
'I knew what I wanted, that's important. But where architects are really great is that, quite often, you don't think practically'
That was 2006. He rented the ground floor out as a café and did the middle flat up with £30,000, but couldn't raise enough to do the top straight away. Finally, things got going. Mark's ex, Umberto Emoli, an architect at Emoli Petroschka, which now rents the street-level office, suggested Threefold Architects, which did the overarching design.
"I knew what I wanted," says Mark. "That's important. But where architects are really great is that, quite often, you don't think practically. Though I think women are more practical than men. Take storage, for example. Or this all-white kitchen. It looks fabulous — but it's really difficult to keep clean.
"There were some things I really wanted. A bi-folding door out to the deck, and an outside space that was seamless with the sky and the room. These windows are highly insulated double-glazed self-cleaning glass with a solar coating. Umberto designed the glass balustrade. It's great, you can hardly see it."
Of course, there were a few problems along the way. Three sets of builders, for a start, as the first lot went bust; and a bathroom that he and Umberto redesigned after the builders finished. But on the whole, things worked out.
'I never feel like I'm inside. It's like you're involved in what's going on'
Mark finds it really easy to live in a four-sided glass box, though it's too bright to watch TV in daylight. But he loves it, not just the ever-changing weather, but the constant activity on the streets all around.
"I never feel like I'm inside. It's like you're involved in what's going on; whatever is happening, you feel as if you're part of it. And after a while you stop being self-conscious, too. I'm really calm here — it's like being on a beach."
The strength of this remarkably serene top floor is its simplicity. Cradled by its steel frame, it really is just glass, with a lightly limed pale oak floor, a big white Ikea island kitchen, with lots and lots of storage, and with a silky, custom-made white Corian top; two Mies van der Rohe white leather Barcelona chairs, and a stunning leather sofa. "That was nearly £5,000 at Sofa Italia on Tottenham Court Road," Mark says. "But I tracked down the manufacturer and got it for £1,200."
Yet, when he wants privacy, it is just downstairs, and it is this common sense that makes the duplex work so well. The floor below has two interconnecting bedrooms, simply furnished, each with a useful wall of wardrobes, and a bathroom lined in porcelain tiles that look like slate: "Cheap as chips," Mark declares. The beautifully simple walk-in shower is from Bathstore. And the floor-to-ceiling doors to all rooms, in specially mixed chocolate brown, add glamour. They were also something he particularly wanted.
Building this ambitious home has taught him a great deal. "You learn a lot about who you are when you do something like this," he says. "At the time, you can't separate your emotions from what you want to achieve, and the stress can make it hard to see things clearly. So you really need guidance from an architect or project manager you completely trust, and who understands everything, down to the last nut and bolt."
It has also made him fall in love with the neighbourhood. "This area feels like Notting Hill did 15 years ago. I'm seduced by it — the East End is a seductress. The local people are the most friendly I've ever lived or worked among."
Getting advice and the look
* Buying the building: £451,279
* Doing the work: about £430,000
* Finance: arranged by Mark, an independent financial adviser, through Ashton House (01582 478877)
* Architect: Threefold Architects (threefold architects.com)
* Additional design: Umberto Emoli (emolipetroschka.co.uk)
* Barcelona chairs: £587 each (barcelonachaircompany.co.uk)
* Bathroom shower: bathstore.com
* Affordable tiles: toppstiles.co.uk
* Kitchen units: Ikea (ikea.com)
* Worktop: Corian by Dupont; can be specified by architects or builders
* Specialist paints: Lacquer Studios (lacquerstudios.com)
Pictures by Ian Routledge