A concrete 1970s office block has been granted listed status.

The building, known as The Pavilions, had a bunker built in as it was considered to be a target for Soviet missiles during the Cold War.

Built between 1975 and 1978 in Bedminster Down, Bristol, it was handed the heritage status because of the building’s energy efficiency, outstanding design and positive working environment.

It originally featured a swimming pool, internal gardens and the underground bunker – and has now been listed because of its history.

Deborah Williams, west team leader at Historic England, said: “The former Central Electricity Generating Board office is one of a very small number of outstanding office buildings of the 20th century.

“Built to the designs of Arup Associates, the building successfully combines energy efficiency with outstanding design to create a modern office setting, which provides an attractive and positive working environment for employees as well as conveying a strong corporate image.

“Set within a carefully designed landscape by Peter Swann, the “campus-style” offices are now home to Computershare whose vision for the building recognises the unique architectural qualities which have led to its listing, allowing the past to be part of the future.”

The Pavilions were given listed status by the Culture, Media and Sport Secretary in January following a recommendation from Historic England, formerly English Heritage.

In its report, Historic England described the building as “an excellent example of a low-energy commercial building of the 1970s”.

Financial services company Computershare bosses are celebrating by throwing open the doors to members of the public. People who want a guided tour of the offices on Bridgwater Road, Bristol, will get the chance on Saturday, September 12.

Naz Sarkar, chief executive of Computershare, said: “We are really pleased to be working with Historic England to offer members of the public a chance to have a closer look at this iconic architectural treasure.

“We know it has played a significant role in the lives of many local people, with so many telling us they have worked here, were involved in its construction or have visited over the years.”

He added: “We have worked hard at retaining the building’s unique attributes while adapting it to the needs of a growing, modern business, and we expect visitors will get a glimpse of its fascinating past – as well as its dynamic future as our national and regional headquarters.”