The building will house new premises for the Alan Turing Institute
Proposals by Rogers Stirk Harbour and Partners to extend the grade I-listed British Library in London have attracted criticism from rival architects and heritage groups.
Plans for the scheme, which are due to be lodged with Camden planners in May, will see a block at least 11 storeys built next to and partially attached to the landmark existing building at St Pancras which opened in 1997 and was given the highest form of protection in 2015.
It will include 72,000sq m of office space, 10,000sq m of library facilities and new premises for the Alan Turing Institute.