The external envelope of the building has experienced problems for several years and significant work is required to ensure the building remains watertight.

All of the building’s curtain walling, rain screen cladding, glazing, stonework and the roof will be replaced as part of the contract.

The job will see the building transformed into a low energy storage space, significantly reducing energy consumption.

Around two million maps, atlases, gazetteers, and cartographic reference works and periodicals are stored in the Causewayside building, which opened in two phases in 1989 and 1995.

Causewayside is the largest property within the National Library of Scotland’s estate and extends to more than 19,000m² over seven levels, two of which are below ground.

Over the years, the compound effect of deteriorating materials and complexity of the building design has led to the issues which now require correcting.

Regional director at Graham Construction, Neil McFarlane, said: “We are therefore working to develop a solution which will allow these documents to remain in place while still giving us the necessary access to complete the works.

“We intend to take a phased approach to the project, with the first half of the work completed by the first half of 2016 and the entire scheme completed by 2018.”