Sir Philip Powell

Half of the humane modernist architects Powell and Moya

Arnold Joseph Philip Powell, architect: born Bedford 15 March 1921; partner, Powell and Moya 1946-76, Powell, Moya and Partners 1976-91; OBE 1957; ARA 1972, RA 1977; Kt 1975; CH 1984; Treasurer, Royal Academy 1985-95; married 1953 Philippa Eccles (one son, one daughter); died London 5 May 2003.

"If my brother had become an accountant, I'd have become an accountant," said Philip Powell at a meeting last month of DoCoMoMo, the society dedicated to the documentation and conservation of the Modern Movement of which he was honorary president. Instead Michael Powell became an architect, and his brother, five years younger, duly followed him to the Architectural Association.

There Philip Powell met the American Hidalgo ("Jacko") Moya, with whom he formed a partnership. "Two Powells and one Moya equalled 'Powell and Moya'," he explained, although his brother Michael soon left for the more secure world of the London County Council's Schools Division. Michael's early death in 1970 still upset Philip 30 years later.

The Powells' father, Canon A.C. Powell, had been Headmaster of Bedford Modern School and then of Epsom College. Philip Powell was born in Bedford, in 1921, and went to school at Epsom. Despite the shortage of work, the Second World War years were exciting times in which to become an architect. The Architectural Association was evacuated to Hadley Wood, where Powell, Moya and their contemporaries shared a house, and they repeated the experience back in London, where they, their friends, wives and girlfriends moved into the Little Boltons. Powell finally bought the house in 1957.

The regular articulation of the pairs of villas informed the regular rhythms and comfortable proportions of his own work, very different though it was in style. It was there that Powell and Moya drew out their entry to Westminster City Council's competition in 1945 for housing in Pimlico, Churchill Gardens. It was the first competition held after the war and, against a strong field and aged only 24 and 23 respectively, Powell and Moya won.

Theirs was a humane modernism, despite the necessarily high densities. The lines of flats, angled to the river, were tempered by a sinuous road curving between them, by jaunty rooftop lift towers, children's playgrounds and brilliant colours. The round glass accumulator tower, which stored waste heat from Battersea Power Station across the river, acted as a further foil, as did the Georgian terrace and Victorian pub the architects insisted on retaining as part of the scheme. Powell and Moya won a Civic Trust Award for the buildings, and also one for the landscaping.

Yet, whereas other architects can be precious about their buildings, Powell was cheerfully content to see changes made, and freely advised Westminster on alterations to the blocks in the 1990s. He combined a genuine modesty with a dry wit and steely intelligence. While Moya immersed himself in design work, Powell could combine design with administration and committee meetings, necessary for a small practice often engrossed for years in the design of large hospitals or university complexes.

Powell and Moya's work personifies the best of post-war architecture. At a time when jobs were scarce, they won another competition, in 1950, for a vertical feature at the Festival of Britain. Each prepared a design, but "Jacko's felt so right that there was no point going further and we collaborated after that". The result was "Skylon", still an abiding image of the festival.

They went on to design more housing, in north London and in Harlow, and a school in Putney. But meanwhile another contemporary from the Architectural Association, John Weeks, was working on hospital planning for the Nuffield Foundation. Asked to recommend an architect for a new hospital at Swindon, he unhesitatingly recommended Powell and Moya as "the most brilliant firm in the country".

There began an association with hospital design that was to last into the 1990s, the firm always seeking to make their buildings less intimidating, and scoring a singular success with a hospital at Wexham Park, outside Slough, that was largely a series of single-storey courtyards. "Hospitals swamped us, rather," Powell later confessed. For, in a bid to keep the practice small, Powell and Moya routinely turned down many offers of work, or declined to enter prestigious competitions they might easily have won.

Powell and Moya came to maturity with buildings at Oxford and Cambridge universities. This connection began at Brasenose, where they were commissioned "to fit in, squeeze in, as many rooms as you can without being antisocial about it" into a backyard full of bicycles. They showed that a British firm could build an accomplished modern design that also harmonised with its historic surroundings, at a time when St Catherine's College was courting controversy by employing the Danish master Arne Jacobsen. Like Jacobsen, Powell and Moya also designed all the interior fittings and the landscaping for their scheme.

Powell's "unique capacity for dealing with difficult people" and for "adapting modern architecture to an Oxford setting" led to commissions at the colleges Christ Church and Wolfson, and at Cambridge. Powell considered the picture gallery at Christ Church his favourite building, "because I like buildings that you can't see". This modesty belied the brilliance of Powell and Moya's solution to the difficulty of building on a constricted site hemmed in by some of the finest architecture from the 16th and 18th centuries, of concealing the building behind the Dean's garden and creating a new internal courtyard.

Powell created a similar courtyard at the Museum of London (1971-76), squeezing two levels of exhibition spaces into a tight site constrained by the high walkway of London Wall on one side and Ironmongers' Hall on the other. And at St John's College, Cambridge, Powell and Moya devised an uncompromisingly modern block that sinuously and unashamedly wriggled between its ancient neighbours, somehow enhancing their venerability with its own clean lines and good looks. In 1974 Powell and Moya became the first practice, rather than individuals, to win the RIBA Gold Medal for architecture.

For many years Powell served as a dedicated member of the Royal Fine Arts Commission, and was deservedly awarded a knighthood in 1975. He was made a Companion of Honour in 1984. He remained a twinkling presence, always willing to answer queries when "at his best, in the mornings" and to attend events, despite his increasing frailty.

Elain Harwood