The National Archive
Client: British Film Institute
Our Approach
The brief
The National Archive is a department of the British Film Institute and one of the largest film archives in the world. The client required a new-build facility to store flammable nitrate film and sensitive acetate film at the ideal conditions to maximise the preservation period and minimise risk of damage.
The facility consists of six large acetate cells at the centre of the building, surrounded by 15 smaller nitrate cells along each side. This modular approach meant that, in the unlikely event of a fire in one cell, the contents of the remaining cells would be safe.
The vaults hold over 450,000 canisters of film in cold and dry conditions of -5oC at 35% relative humidity to aid their preservation, while the fabric and services enable the environment to be maintained in an energy efficient way. It is believed to be a ‘world first’ store of this size at these conditions.
Project highlights
The structure was designed as a very high mass concrete building and the internal concrete walls and ceilings were left untreated and therefore were porous to moisture. If moisture loads in the rooms increase as a new collection of film is introduced, the walls act as a sponge absorbing some of the excess moisture. The ventilation systems then slowly remove the moisture from the room and the concrete, stabilising the conditions.
CPW were able to achieve outstandingly low air permeability rates, minimising the amount of leakage from the building and far exceeding Passivhaus standards. The National Archive delivered over 70% improvement on an exemplar low energy building and 97% better than Building Regulations limits. The optimum conditions were achieved without any additional carbon or financial cost in operation, achieving BREEAM ‘Excellent’ in the process.
Bespoke solutions
To maintain this environment, a very efficient two stage process was employed to recover heat from the dehumidification and pre-heat the regeneration air. This created minimal heating load which in turn removed the requirement for a natural gas infrastructure to the site.
Heat rejected from the air-cooled chiller is recovered and used to heat the ancillary support areas using under floor heating, fan coil units and close control units operating at 45°C flow /40°C return. The building is served by a chilled water system operating at unusually low temperatures of –12°C flow and –6°C return to maintain the required internal environment, so efficient heat recovery is even more critical.
Innovation
This building presented a considerable challenge in the need to safely store 268,380 cans of acetate film, and 190,080 cans of nitrate film dating back to 1889. The very low ignition temperature and fast burning rate of this film resulted in a high risk of combustion.
The team had to find innovative solutions to meet the optimum conditions for storing this film at a very cold and dry conditions efficiently.
The final technical solution for this building is the result of intense research and collaboration between the architect, engineers, film experts and the BFI to determine the best method for storing such a large collection of film sustainably for many years to come.
The thermal mass of the building is essential in order to provide a stable internal environmental condition. A heavyweight design has been employed to minimise the impact that any variation in the external ambient conditions will have on the facility. The mass and high insulation levels mean that, even if power is lost to the site, the building can maintain the collection below freezing point for three days.
The pioneering achievement sets a new benchmark for archive design.
BREEAM ‘Excellent’
EPC ‘B’
‘Sustain’ Magazine Award for Design & Architecture (2013)
RIBA Award and Regional Building of the Year (2012)
AIA UK Excellence in Design Award Commendation (2012) Building Awards Project of the Year Finalist (2012)
BCI Awards Building Project of the Year (£3m to £50m) - Highly Commended (2012)
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Photography courtesy of the BFI and Edmund Sumner Photos