'This house has been in my head for 20 years,' says Angad Paul as he takes us on a tour of his new London home. 'I wanted to create a Case Study House in an urban context,' he says referring to the pioneering mid-20th century hilltop American Case Study Houses that sought to bring modernism and functionality to the masses. Paul is chief executive of Caparo manufacturing group, and also chairman and co-founder of British design company Established & Sons; his new three-storey penthouse conversion is on top of Ambika House, a late-1950s block in tree-lined Portland Place. Paul grew up in the building, named after a sister who died of leukaemia before he was born, and as a young bachelor, he relocated to the caretaker's flat on the roof. The roof used to be 'a mess of tiny brick buildings that mainly housed water tanks and lift motor rooms' according to Matt Yeoman, founding partner and director of the East London-based architectural practice Buckley Gray Yeoman that designed the house. The fact that Paul wanted the space converted into a home for his solicitor wife and young family says a lot about how much this building, this part of London, and the astounding views mean to him. Paul was clear from the start that it had to be a home, rather than a showpiece, so he chose materials for their durability and warmth; he didn't want the space to look like an art gallery. This rationale explains the use of a thin super-compressed industrial ceramic tile on most of the floors, instead of the original idea of Portland stone ('a very subtle detail that doesn't make it feel like a mansion,' says Yeoman), reclaimed yarrow in the living room floor ('I really want it to crack and look worn,' says Paul) and Corian in the family bathrooms. On the walls, he chose an almost luminescent polished plaster for what he calls its 'tactile quality'; for the skirting and door panels, he used Corten steel. 'I love Corten steel, so I used it where it's not obviously used,' says Paul. 'It was a drawn out process,' says Yeoman. 'Angad's fascinated with detail; he's fascinated with materials. Some of the design sessions, we'd agree on something and then he'd see a [material] he liked and say 'this is what I want to make my bath out of.'' It's indicative of the level of input Paul had as a client. 'I'd much rather have someone like Angad, than somebody who's oblivious,' says Yeoman. 'It's engaging, that's why you do it.' Another key concept at Ambika House was what Yeoman calls 'bringing the outside in' - the lounge's living wall, the skylights, and the vast wraparound windows on the top floor, all go some way in making the inside and outside become one. Paul wanted to plant a tree in the middle of the house, but has settled with trees and a sedum roof on one of its terraces. As we walk around, Paul points out space-saving devices such as a pull-out tie-rack hidden in the walk-in wardrobe, or the way the childrens' fitted wardrobes fill the gap behind the house's control room. 'I love that whole boat design utilization of space,' says Paul. Paul consciously chose to fill his home with furniture by Established & Sons, but there are exceptions, such as playful shelves by Magis, nest-like beds for the kids by Italian firm Lago (their soft frame reminded Paul of 'trampolines'), and mini Panton chairs for the children's desks. There are also family heirlooms scattered around the three storeys. Paul's favourite part of the home is the master bedroom at the north end. He shows me the bed, which was made by Studio Caparo and appears as if 'suspended and floating'. He also demonstrates the ingenious mechanism that lifts a flat-screen TV out of a low wooden console ('it's built right into the ground,' he says). Though the whole house is about the views - from various points you can see the London Eye, the BT Tower and Battersea Power Station - it's the vistas from his bedroom that most appeal to him. 'If I had to take an establishing shot of what London was really like this would be it,' he says, looking out to the steeples of his former school Harrow, and the medley of rooftops and chimney stacks closer to home. 'This is basically Peter Pan's London.' Paul is surprisingly open and relaxed for a man running a conglomerate of 85 manufacturing companies with 10,000 employees that enjoyed a US$1.5 billion turnover in 2011 (the family-owned company was founded in 1968 by his father, a Labour peer). When we leave, Paul's two children are milling about in various states of undress, his wife is chatting to her mother, and a friend has come over to do some yoga in the pool room. The family is doing their thing; they just happen to be surrounded by some of London's most tantalising views. Objects of desire The large living-slash-dining room is where Paul's passion for design comes to life. It's a showcase to Established & Sons, but a lived-in one where objects are well loved and his children use the limited-edition Chester sofa by Amanda Levete as a slide. 'You can't be precious about things,' says Paul. 'It's a home.' BarberOsgerby's panoramic modular sofa system dominates the living area. 'It has some of the most interesting lines,' says Paul. 'You have to look at it from the back, which is why it was perfect for this room.' The coffee table is a first prototype hand-beaten aluminium version of the Zero-In, also by BarberOsgerby ('I love the orange of it'), the side tables are Deltas 'also by Ed [Barber] and Jay [Osgerby]', and the lamp is the lighthouse by Ronan and Erwan Bouroullec. In the dining area, the pure forms of Terence Woodgate and John Barnard's super-thin Surface Table are contrasted with 10 of Spanish designer Jaime Hayon's more flamboyant Tudor Chairs (the Maarten Baas 'Standard Unique' chairs in the photos have migrated to the sixth floor). 'It's against that table that the chairs really take on a form and a life,' says Paul. To the left, there's a Tudor Cabinet by Hayon and a Two-Timer clock by Sam Hecht on the wall. By the living wall, three burgundy Quilt sofas (designed by the Bouroullec brothers) surround a first prototype of the Iris 1500 low table by BarberOsgerby. There's an Audrey Vase by Michael Eden here and some Nekton seats by Zaha Hadid nearby. If this sounds like Established & Sons overkill, surprisingly, it isn't. In fact, it might just be a testament to how different and unique the brand's designers really are. As Paul says: 'All these pieces are quite quirky, but they have a similar essence of quality and thought.'