The Hill House is arguably Charles Rennie Mackintosh’s residential masterpiece. A hybridisation of tradition and invention in the construction of the building has led to fundamental long-term problems of prolonged water damage. Rather than incarcerate the house away from view while the restoration is undertaken, a more radical approach to active conservation was taken. A ‘big-box’ temporary museum to contain and protect the Hill House as an artefact was built, allowing the house to dry out and be conserved, and enabling visitors to see the conservation process.