Steve Morrison is fed up with hearing that his school’s multi-million pound redesign is responsible for its remarkable turnaround in performance.

The head of Kingsdale, a once run-down school in south-east London, spoke out as Hilary Cottam was named designer of the year, picking up a pound;25,000 prize for work on the Dulwich comprehensive.

Mr Morrison said that Ms Cottam, a Design Council director, had played no part in the school’s improved results: “She has played no part in this transformation of Kingsdale to date. Absolutely no part whatsoever.”

He said: “What people cannot accept is that a school with a black head and with so many ethnic-minority children in it could come up with ideas so powerful.”

Ms Cottam was awarded her title by the Design Museum for her inventive use of “design thinking” to renew public services, including schools, hospitals and prisons.

The pound;12 million redesign of Kingsdale with its vast, shimmering atrium and soaring membrane roof, its pod-like double-skinned geodesic auditorium, elevated walkways and state-of-the-art IT suites is exhibited at the museum as a key feature in her portfolio. Alice Rawsthorn, the museum’s director, says that Ms Cottam had been chosen for her incredible impact on the public sector and for her “use of design in a broad sense to achieve real improvement”.

But Mr Morrison, a member of the London leading heads group, says he is sick and tired of stories in the press and on design websites which give the impression that Ms Cottam’s work transformed Kingsdale.

He said any improvement was due to the strategic planning and improvement targets he and his senior team drew up when he was appointed head in 1998 to pull the school out of special measures.

In 2002, before the building programme began, Kingsdale became one of the top 20 most improved schools in the country with A* to C GCSE pass rates rising from 17 to 41 per cent.

Mr Morrison said transforming a school like Kingsdale, where 50 per cent of pupils are on the special needs register and two-thirds are eligible for free meals, was a long and complex business.

Moreover, Mr Morrison says, key features of the re-design - the atrium, membrane roof, pod, walkways - were inspired by the staff. The long narrow corridors, a breeding ground for truancy and bullying, were knocked out to make way for the atrium.

Ms Cottam brought in a psychologist and a performing artist who worked on a rap with children to raise self-esteem - but it was not deemed good enough to be used in the school’s annual music festival.

Ms Cottam would not be drawn into answering specific criticisms but said the upset had arisen due to a “misunderstanding of what design entails”.

“I have always acknowledged that the work at Kingsdale was a collaborative team process in which the staff, pupils and community played a pivotal role,” she said.

* newsdesk@tes.co.uk