IT will store seven million books and documents, has cost £26 million to build and uses robotic cranes to retrieve items from the shelves.

Welcome to the new extension to the British Library at Boston Spa – the most advanced library storage facility in the world.

The huge building, opened today by regions minister Rosie Winterton, will store 262 kilometres worth of items in a temperature and humidity controlled environment to aid their preservation.

The air has low oxygen levels, similar to that found 3,000 metres up a mountain, to prevent fire breaking out.

Items will be stored in 140,000 bar-coded containers, which can be retrieved automatically by seven robotic cranes which sweep up and down the storage void.

Two lorryloads of books and documents, including patent specifications, are being taken to Boston Spa each day as the British Library vacates a range of buildings in London, but not its St Pancras headquarters. A spokesman said the extension would help safeguard the jobs of 900 employees at Boston Spa, of whom 200-300 live in York.

He said that planners at Leeds City Council would later this month consider a separate £33 million scheme for another building to store the national newspaper collection, which would hold every single copy ever published of papers such as The Press and its predecessor the Yorkshire Evening Press.

Ms Winterton said she welcomed the Library’s commitment to the long-term development of the Yorkshire site to safeguard the national collection for the future.

“This is an exciting development for the British Library and I am delighted that the site at Boston Spa has been chosen as the location for such a nationally significant facility,” she said.

“As a major employer, the investment demonstrates real confidence in our regional workforce.”

Steve Morris, director of finance and corporate services at the library, said the new store and the newspaper building were part of a 70-year masterplan for the Boston Spa site.

“We’re making a long-term investment which will ensure that this substantial part of the UK’s intellectual heritage survives for future generations of researchers.”