A key building at a top school in Ipswich has been given Grade II-listed status in honour of its “innovative design”.

Ipswich School in Henley Road already has Grade II listing for the main school building and school chapel, which were both built in 1852.

But earlier this month the school’s library and teaching block, which were built between 1980 and 1982 were awarded the same status by Historic England.

Historic England said it was an “innovative design which reflects a modern expression of the architect’s traditional approach to materials and plan-form” and recognised it as being the last major work by Birkin Haward, considered one of the foremost post-war architects.

It also hailed the stained glass by John Piper, a leading British artist and its integration with the building’s design.

Historic England added that the collaboration between the school and architect was “clearly demonstrating the aspirations of a progressive independent school”.

The building was commissioned by the school’s headmaster at the time, John Blatchly, who was also a close friend of Birkin Haward.

Current school headmaster Nicholas Weaver said: “Ipswich School has always played a significant role in the history of our town and we are delighted that the school’s library has now been recognised for its special architectural and historic interest – this is a tribute to the lasting contribution of former headmaster John Blatchly to the buildings of Ipswich School.

“The Birkin Haward designed building with the John Piper stained glass windows representing the four seasons is an iconic part of Ipswich School, but one which is perhaps hidden from view behind the school’s famous Henley Road façade.

“I would encourage people to visit the school on Saturday September 15 in the morning as part of the Heritage Open Day, where they will be able to see the library and learn more about its history.”

Listed buildings are those recognised for being architecturally or historically significant, with a listing status helping protect them under planning applications.

John Norman, Ipswich Society chairman said: “Historic buildings are an important part of our heritage, telling the story of our past, its social and economic history.

“They are an ever declining stock, lost to fire, neglect and deliberate damage yet they cannot be recreated.

“We can create an illusion of what was there before but it can only ever be a copy, thus it is essential that these valued buildings are protected.”

He added: “The Ipswich Society welcome the listing of these additional buildings at Ipswich School, particularly as the whole school creates a group value, some buildings by notable local architects.”

Councillor Carole Jones, portfolio holder for development and museums: “We are lucky to live in a town where history and heritage is celebrated wherever possible, and this latest recognition of Ipswich High School raises yet another toast to Ipswich and its commitment to preserving sites that are of historic significance.”