The existing roof covering to R55 Target Station 1 has reached the end of its serviceable life and is experiencing recurring water ingress events which present a risk to scientific operations, equipment, and business continuity. A full roof refurbishment is required to provide a durable, weatherproof building envelope and ensure the facility remains operational for the long term. The existing roof construction comprises a 1960s Flintkote Monoform roofing system installed over a reinforced wood wool deck, with a subsequent refurbishment undertaken in the 1990s. Investigations have identified widespread deterioration of the roof covering and saturated insulation within part of the southern gutter. The proposed works comprise refurbishment of approximately 4,800m² of roof covering through installation of a new overlay roofing system, together with localised replacement of failed insulation within the southern gutter area and associated alterations to roof-mounted services and lightning protection systems as required. A thermal upgrade has been assessed but is not considered technically feasible or economically viable due to the existing roof construction. The proposed roofing solution will therefore focus on delivering a long-life waterproofing system while incorporating a high-reflectivity finish to reduce thermal loading on the building and roof structure. The project will be undertaken within an operational scientific facility and will require careful coordination with building users, existing plant and equipment and lightning protection systems.