HOK Conservation has completed an £8m restoration of the oldest part of the British Museum. Completed in 1827 the King's Library – one of the noblest neoclassical halls in Europe – has been converted into a gallery. The hall, which houses a permanent exhibition devoted to the enlightenment, has been cleaned, repainted and fitted with a fresh lighting system. Mansell was the contractor, Alan Baxter & Partners structural engineer, Klimaat Consulting Engineers services engineer and Davis Langdon & Everest quantity surveyor.