It is unusual when working on historic buildings to have the opportunity to mix traditional materials with modern state of the art ones. When the London Borough of Wandsworth decided to re-roof this notable landmark they decided to do just that. The extensive flat roof areas over modern extensions were recovered with a high performance built up system manufactured by Esha. To contrast this the main pitched roof slopes were re-slated with natural Welsh slates and code 6 lead was used to reline the parapet gutters.

While the building was enveloped in scaffolding the grime of more than 100 years smog and pollution was removed with chemical agents and high pressure washing. The soft red brickwork and damaged sandstone were pointed and repaired.