The directors of the Natural History Museum in London are under fire over plans to split parts of its world-renowned collection of biological specimens on a permanent basis. Some of the museum's curators are angry that plans for a new building to store the bulk of the museum's entomology and botany collections remain unaltered three years after being branded unfit for the purpose by museum staff.

Work has now started on the £73-million (US$140-million) building for the Darwin Centre Phase Two, even though there won't be space to house all of the museum's 28 million insect specimens and 5.5 million plants. The structure will replace the previous Entomology Building, which was demolished in 2006: it had been impregnated with potentially cancer-causing naphthalene, which helped to preserve specimens.

Safe storage of specimens such as those of the order Lepidoptera is a Natural History Museum concern. Credit: NHM

“Our first gripe is that they wilfully destroyed a sound building without looking at the alternatives,” says Henry Barlow, an entomologist who contributed some 30,000 specimens to the museum's collections and a member of Friends of the Natural History Museum, a group of donors and visitors that liaises with museum staff. Barlow accuses the museum of being more interested in winning architectural awards than properly curating its collections.

Museum directors found that refurbishing the previous building was not cost-effective, says the museum's head of collections, Mike Fitton. He says when the new building opens in 2009, it will offer better conditions for specimens, better research facilities and improved public access, so visitors can see the museum's research in action. “The collections have not lost out to architecture — they have lost to these three aspirations,” he told Nature.

The Friends of the Natural History Museum will meet with museum director Michael Dixon on 22 May to discuss the plans. “Some fairly pointed questions need to be asked,” says Barlow.

Chief among these will be why the new storage facility, known as the 'cocoon' after its curving walls encased in an eight-storey glass box, will have only 3.4 kilometres of shelving for storing specimens, even though a 2001 report by the museum's trustees said that 4.6 kilometres of shelving was required.

Fitton says the museum commissioned a study at the project's inception in 1999 to evaluate the idea of storing all the collections under one roof. But with the selected design, by Danish firm C. F. Møller Architects, this was considered impractical, and the 2004 unveiling of the design to museum workers was met with anger (see Nature 432, 659; 2004).

The public will get an unprecedented insight into how the institution's painstaking taxonomic research is carried out.

Researchers' fears for the collections are exacerbated by the fact that the specimens are currently being kept at the museum's overspill facility in Wandsworth, southwest London. Barlow says this building is prone to high humidity and is below the flood level of the nearby River Thames, but museum officials say conditions are first-class.

It remains unclear whether some specimens will stay in Wandsworth permanently after the new building opens, or whether space will be found elsewhere on the museum's main campus in central London. Of the 129,000 drawers in which the entomology collection currently sits, there will be room for 120,000 in the Darwin Centre, says Fitton. “We could have squeezed all the insects in but that would be silly,” he says, because the collection is expected to grow by around 10% during the life of any storage facility.

Meanwhile, museum directors say the public will get an unprecedented insight into how the institution's painstaking taxonomic research is carried out. Planned attractions include an 'Explore tour', which will take visitors through selected parts of the collection and labs, and the David Attenborough studio, named after the well-known zoologist and broadcaster, which promises face-to-face interaction with museum staff.