By BBC News
A storage facility made of hemp is being erected at the Science Museum at Wroughton in Wiltshire.
The former airfield near Swindon is the large objects storage facility for the London Science Museum, housing more than 16,000 objects in 11 hangars.
As part of an £800,000 project, the hemp building is being installed inside one of the hangars to reduce humidity.
Matt Moore, from the museum, said: "Essentially it will be deep storage - preserving objects for evermore."
He said: "The environment in the hangars for the majority of objects is pretty good, pretty constant, but some items with wood and leather would do better with not quite so much humidity to preserve them for even longer.
"So we've gone back to basics and have decided to use hemp to stabilise the environment."
Lime Technology is supplying the pre-fabricated hemp building.
Ian Pritchett, the company's technical director, said: "We build lots of hemp buildings but this is a building within a building which is far more challenging.
"The hangar is fairly enormous - about an acre of space."
Construction began in January and is due to be completed by the end of April.
"It's a bit like that child's tile game," said Mr Moore.
"As we refurbish a hangar, we can get more stuff into it and so we're moving objects when there's a space free to move them.
"We originally wanted to do all the hangars at once but we've got a more moderate approach now."