In the Sixties, when his buildings rose, brutally dominating the London skyline, few had a good word for the works of Colonel Richard Seifert. Least of all architects, aesthetes and style leaders. But, says Nonie Niesewand, perhaps his style moment has come.

Colonel Richard Seifert's Sixties buildings are hardly considered London's smartest places. For decades they were a blot on the landscape. So large. So brutal. Not the world's wisest property investment. The massive ones, like Centre Point at the bottom of New Oxford Street, became national scandals.

At first sight, a Seifert's late-Fifties leather tannery warehouse in Notting Hill gate is not an inspiring place. But behind a two-storeyed chunky industrial brick face, it hides its huge open spaces of 1,200 sq ft. The Polish architect Miska Miller and her husband, the designer Ross Lovegrove, have made it their office and their home. Miller admits: "I'm not a big lover of this period, the Sixties in London. I mean, it was a distortion of wonderful modernist ideas that frequently lost the proportions." But she likes the way that the factory was planned to go horizontally, not vertically like so many London houses.

Its stolid concrete and steel structure meant they couldn't do much about changing the internal layout. Just putting in a staircase took a lot of nerve and a week of power drilling. Because their practice is on the ground floor, and they sleep and bathe above, they added an open-plan third floor, which mirrors exactly Seifert's proportions.

"Warehouses by Seifert are respected over here these days. They are good projects to build upon because they are so honest. But this doesn't have the clarity of construction and feeling of lightness or the wonderful use of materials that I really like."

The biggest change they made was to cover the outer brickface in a sandy natural-coloured render to lighten it up. They added glass blocks at the ground floor to help the natural light, and bigger windows that follow the same grid as Seifert's on the next floor. Rooflights let in more light to the top floor.

Other people are starting to see the virtues of Seifert's buildings and enjoy them. For a start, there's that big open horizontal grid he built on. Seifert, in his 87th year, is around to hear the good news. He still goes into work almost every day.

Perhaps the first person to spot the Seifert virtues was the Frenchman Patrick Dermoy. A decade ago he opened his furniture and interior design shop Atrium, in a Seifert shell below Centrepoint - "in a wind tunnel but you learn to live with it".

He really wanted to live there. "I first saw it in 1985, all boarded up, just a big, empty box. There was absolutely nothing in it, not even the mezzanine, let alone a phone-line, 17 years after Seifert had designed it. I asked my solicitors to get in touch with the landlord, who was Harry Hyams, but he wouldn't rent it to me. Eventually I wore him down. As a modernist I did not want to go into premises which had been refurbished.

"When we moved into Centrepoint it was more than half empty. Now the whole place is full of financial corporations. But that marvellous horizontal plane. There was never any doubt in my mind that we could keep to the spirit of the building and add to it."

Once upon a time one would never have expected to hear an architectural expert talk enthusiastically about Centrepoint: "It's like a Bridget Riley building that rises a mile high," says Dr Neil Bingham, assistant curator at the RIBA Heinz Gallery. Does this sound like the much reviled Centrepoint building to you?

He is enthusiastic as he catalogues a collection of perspectives of Richard Seifert's buildings from the Fifties, Sixties and Seventies. "These drawings are perfect time pieces of Colonel Seifert's pop buildings," he says. Perspectives from Seifert's practice drawn by his watercolourist, a certain Mr Gill, include prelims of Centrepoint, the round Civil Aviation building at Aldwych, the Times Building, and a huge model of the Nat West tower from1971.

RIBA Heinz Gallery is at 21 Portman Square, London Wl (0171-307 3605)