This pioneering new Master Film Store preserves the British Film Institute's (BFI) master film collections of nitrate and acetate film. The building is the first of its kind to store large quantities of film, over 450,000 canisters, in optimal environmental conditions.The building is the result of intense research and collaboration between the architect, engineers, film experts and the BFI to define the best solution for storing this large collection of film, sustainably, for the next 50 years and beyond. The vaults keep the film in cold and dry conditions of minus 5 degrees C at 35% relative humidity, while the fabric and services enable this environment to be maintained in an energy efficient way.Although the building form is quite simple, consisting of 30 identical cellular vaults of nitrate film and 6 vaults of acetate film, the specification required an extremely low air leakage rate of 0.3m3/hr @ 50 Pascals to maximise performance.Rigorous analysis, detailing and quality control has been carried out to ensure the building will provide the sub-zero temperature, low humidity and fire prevention that the film requires for its preservation. The building will achieve a BREEAM 'Excellent' rating.