The NMRC in Swindon, part of the Royal Commission on the Historical Monuments of England, is the country’s major repository of data and photographs on historic sites and buildings. To enable the centralisation of previously scattered (and cramped) services, developer Tarmac and Studio director John Muir renovated a complex of 19th and early 20th century railway offices built over 80 years on behalf of successive chief engineers of the Great Western Railway. These were robust, utilitarian buildings that were clearly ‘of their time’ and the client sought a similarly contemporary feel to new insertions and additions. The buildings were neglected and blackened externally, but largely sound in their structures. The policy of minimum interference with the fabric was adopted: the stonework was carefully cleaned, defective windows repaired with reclaimed timber, Welsh slate restored to the roof in place of British Rail’s asbestos cement sheets. Inside, a similar approach led to full-height shafts between masonry walls for service areas and as much open plan space as possible. The L-shaped former drawing room now houses the NMRC’s treasure trove of data and photographs. Complementary to this was a requirement for a bespoke archive store in which to house, in a tightly controlled environment, the most delicate of the collection’s objects. The essence of the design solution is that the new building is ‘hinged’ to the old complex via a transparent glazed ‘bridge’, its siting creating a courtyard for staff use.