28 C O N T E X T 1 5 9 : M A Y 2 0 1 9 LOUISE PRIESTMAN Servicing Durham Cathedral’s Open Treasure project The Open Treasure project has widened public access to the hidden architectural spaces and collections of Durham Cathedral by making creative use of the claustral buildings. Durham Cathedral, the most significant and complete Romanesque cathedral in Europe, retains a near-complete and intact range of Benedictine claustral buildings. The cathedral houses the largest in-situ collection of medieval manuscripts and early printed books of any English cathedral. Chris Cotton, cathedral architect and partner to Purcell’s York Studio, led his team in the delivery of an extensive programme of works known as Open Treasure. These works were agreed following research to understand the complexity of the project, and to define the brief and priorities. The process included extensive expert research, coupled with programmes of consultation and public engagement. The dean and chapter’s ambition was to widen public access to the cathedral’s hidden treasures, including architectural spaces as well as pieces from the collection. This became a Heritage Lottery Fund project, with other fund- ing streams supporting the project. It included a scaled Lego model of the cathedral. The project’s biggest challenges lay in four spaces which surround the cloisters: the Refectory Library; the Collections Gallery; the Monks’ Dormitory; and the Great Kitchen. Despite their outstanding value, they were most- ly inaccessible and required urgent repairs. The project elements which were intended to form new exhibition and library facilities also had to deliver new environmental controls, set in the context of a historic building constructed from porous materials and with extremely limited plant space. Among other specialist and consultants, Tobit Curteis, David Odgers and TGA Consulting Engineers were appointed to work with Purcell to undertake the analysis of the existing con- dition, while creating sensitive and suitable solutions to manage environmental conditions. Due to the different uses proposed, each space needed its own bespoke approach, including its building services. The quinquennial inspection and report pub- lished in 2013 indicated the requirement for urgent repair works and set out what manage- ment was to be expected. Once the brief had been agreed and the team appointed, the process began undertaking detailed trials, including sampling and materials analysis. This was in conjunction with an extended period of environ- mental monitoring by Tobit Curteis as specialist in environmental monitoring. TGA Consulting Durham Cathedral’s hidden treasures included architectural spaces and artefacts from its collections.