The Royal Academy (London) is a listed building, which hosts numerous internationally acclaimed exhibitions, varying from robust stone sculptures to delicate silk and paper artefacts. Whilst daylight is a desirable medium for accurate colour rendition, it is often necessary to omit direct sunlight and limit daylight to avoid damage to light sensitive exhibits. The challenge was to design a flexible daylight control system that would be unobtrusive within the historic gallery interiors, flexible and equally important reliable. The design also had to be adaptable to suit all of the top-lit galleries, irrespective of their orientation. The design solution was a multi-layered system of diffuse glass, external louvres and internal roller blinds. The latter two being capable of automatic operation, with manual override. A combination of external and internal light sensors constantly monitors the gallery environment to ensure that pre-determined light levels can be maintained.