The new wing to the 1853 Herbarium provides a modern storage facility for the most vulnerable pieces of the existing seven million artifact collection of plant specimens and manuscripts.

The plan is essentially that of a three-story rectangular red brick storage vault, linked to the main building by a western red cedar and glass clad cylindrical three storey building which also houses the reception, library and a circular reading room. The buildings are arranged to create a new entrance courtyard to the side of the main building.

The new storage vaults are designed to keep the collection at a constant temperature of 15 degrees centigrade and use a mechanical air handling and a ground source heat pump to reduce C02 emissions. The building has a BREEAM excellent rating.