Ralph Erskine, one the 20th century’s greatest and most influential architects, has died at the age of 91 after a short illness.

Though English by birth and education, Erkine lived all his professional life in Sweden. Even so, he designed seminal buildings and housing developments in Britain. The most recent of these was the masterplan and high-rise blocks for the Greenwich Millennium Village. Designed originally as a competition entry in 1997, the village is being extended to the plans of his partners, Johannes Tovatt and Geoff Denton.

Even more famous was his daring redevelopment of 2000 homes at Byker in Newcastle, completed in 1981. Here intricate courtyards of low-rise housing are shielded from the urban motorway by the huge crescent-shaped “Byker Wall” of maisonettes. And next to the Hammersmith flyover in west London, he created the curvilinear boat-like office building aptly named the Ark.

All Erskine’s projects were suffused with a deep-seated humanism implanted at the Quaker school he attended in Saffron Walden, Essex. His buildings radiate optimism, appropriateness, wit and, as in the Ark, a delight in childlike rounded forms, all of which have an instant, unsophisticated appeal.

His methods were people-friendly, too: at Byker he was the first architect to set up an office in the community and engage with tenants.