Work has begun on the restoration of the Mackintosh Library of the Glasgow School of Art.

Stonemasons have begun the process of removing the stone piers between the windows on the west wall of the building.

These stones will then be analysed, and those that can be repaired and re-used will remain part of the library, which was severely damaged in the 2014 fire.

The library, which like the rest of the building will re-open to students and the public in 2019, will be returned to Charles Rennie Mackintosh's original design, and will resemble its form in 1910.

Research to source replacement timber is well underway, with wood found in the US, including Tulip Wood.

The restored library will be paler and lighter than many will remember it: the wood from the before the fire had been heavily lacquered and darkened.

It will resemble more closely the "clearing in a wood", the light and airy space Mackintosh originally intended, restoration experts said.

Replacement stone will come from a quarry in the north west of England - the original stone came from a quarry in Giffnock, which is no longer in operation.

Specialists have begun the painstaking job of re-assembling the more than 600 fragments of the original lights which were retrieved following the archaeological survey.

The lights, made from brass, are being re-assembled and cleaned and 53 will be hung in the restored library.

Twenty nine lights will be completely remade from the 620 fragments, seven will be part old and part and new and the rest will be replicas.

The lights will be hung where they were formely placed, as when they were recovered from the ash and detritus of the fire their locations were carefully mapped.

“After months of preparation and detailed research work with the design team we are excited that the restoration work is now underway,” said Liz Davidson, Senior Project Manager for the Mackintosh Restoration.

"The current work will enable us to establish how much to the original stone from the library piers can be re-used in the restored piers.”

“The heat of the fire in the library shattered and fissured the stonework making some of it too weak for reuse.

"As each stone is removed from the piers we are checking to see whether it is strong enough to be reused.

"Our main focus is in retaining as much as possible of the external stonework with its highly skilled tooling and subtle carved profiles – at each layer we will attempt to save and protect these facing stones whilst strengthening the piers from within.”

The project is being supported by the £32m Mackintosh Campus Appeal, £18m of which has been raised to date.

The design team for the Mackintosh Building is led by Page\Park Architects.