Rick Mather obituary

Architect known for his work on museums, he had a rare talent for making the most of every available space.

By Colin Amery. Source: The Guardian.

The US-born architect Rick Mather, who has died aged 75 following a heart attack, left a calm mark on many universities, art galleries and museums during half a century of working in Britain. When his expansion and reordering of the Ashmolean Museum in Oxford was nominated in 2010 for the Stirling prize, the judges from the RIBA described it as "a rich spatial journey". The commission marked the culmination of work made possible from the 1990s by lottery funding and greater private patronage, enabling Mather to demonstrate his rare ability to respond creatively to historic buildings.

The reputation of Rick Mather Architects as international designers was established through the adaptation of three London museums: Dulwich Picture Gallery in the south; the Wallace Collection, in Manchester Square, to the north of Oxford Street; and the National Maritime Museum, east along the Thames in Greenwich. At Dulwich, the first public art gallery in England when it opened in 1817, Mather could engage with one of his favourite architects. Without directly imitating Sir John Soane's design, Mather skilfully added circulation space, a cafe, and lecture and educational facilities that are informed by the original work.

A talent for utilising wasted space came into play at the Wallace Collection, where Mather put a glazed roof over the courtyard garden to create an elegant restaurant and sculpture court. He also created much needed exhibition space and a lecture theatre in the basement, ingeniously expanding a building on a tight urban site. At the National Maritime Museum, the similarly underused Neptune Court was given the largest free-spanning glazed roof in Europe – praised as an "effortless intervention in a Grade 1 listed building" by the judges who gave it a Civic Trust award.

This flair for reinvigorating distinguished but tired institutions made Mather the natural winner of the competition held by the Ashmolean, founded in 1683 and thus the world's oldest university museum. Mather doubled the display space of CR Cockerell's neoclassical structure of 1845. The six-storey extension with a superb bridged atrium and grand staircase at its heart completely transforms the museum, replacing the late Victorian additions and allowing a flood of natural light. A later phase (2011) saw the design of discreet new displays of the Egyptian collections in six new galleries. Mather proved adept not just as an architect, but also in relating to curators, academics, trustees and donors.

A native of Portland, Oregon, Mather had his first architectural experience at the age of 11: his father was an engineer, and Rick helped build a family summer house in a clearing in the woods. After graduating in architecture at the University of Oregon in 1961, he toured Europe, looking at the major cathedrals and the works of Le Corbusier, and in 1963 arrived in Britain.

A spell with the architectural firm of Lyons, Israel and Ellis gave him experience of working on new schools in Yorkshire, and then he enrolled for the urban design graduate course at the Architectural Association School in London. This was something of a turning point, broadening his interest in master planning and urban history. Six years with the London borough of Southwark gave him hands-on urban planning experience.

In 1973 he established his own practice with offices in Camden Town, north London. It took a decade of interior designs, house conversions and a gradual growth of master planning work for universities before his own urbane architectural style came to be recognised. The Anglophile "quiet American" was well placed to please what he called "the G and G's" – the great and the good – keen to pursue building projects in the educational and cultural worlds.

Mather's talents enabled him recently to expand his work to America, where the extension to the Virginia Museum of Fine Arts in Richmond opened in 2010, and work continues on an extension to the Peabody Essex Museum in Salem, Massachusetts. His master plan underpins the next phase of the recovery of London's South Bank: the sensitivity that he brought to his civilising work as an architect was also evident in his friendships, his cultural interests, his own houses and gardens and his infinite and generous hospitality.

He is survived by his partner, David Scrase, deputy director of the Fitzwilliam Museum in Cambridge.

Richard Martin Mather, architect, born 30 May 1937; died 20 April 2013.