A SUSTAINABLE HABITAT FOR BATS
Inspired by the flight pattern of a spinning bat, the Bat Spiral is a dynamic, floating spiral of concrete beams that accommodates roosts for the 17 British species. The Bat Spiral is raised from the ground on a cluster of thin, steel reinforcing bars, which resemble a bed of reeds.
Twenty-four different types of timber roosts are positioned within the concrete spiral as if they were the spokes of a wheel. Each roost position is determined by the orientation to the sun, shade and prevailing winds. The roosts are painted black externally to maximise heat gain from the sun except for the Greater Horse Shoe Bat’s summer roost which is insulated and kept at a constant temperature by earth pipes. Specially designed incubators keep this species insulated winter roost a constant 7 to 11 degrees Celsius.
Gaps between beams allow multiple access points for the bats into four levels of habitation. The design of the roosts provides a variety of spaces, with varying feeding perches, access and egress holes, and the seasonal rotation of bats from winter and summer roosts. Maternity and mating roosts can be added to meet the particular needs of each bat species. In order to minimise use of materials, the roosts are made from reclaimed timber formwork used to cast the insitu concrete base. At the centre of the spiral is a hub of cameras, which allow visitors to view the roosts from a remote hide without disturbing the bats.
The Bat Spiral is based on a 15 metre wide spiral and is constructed from four continuous curving recycled carbon-fibre beams 750mm deep and 150mm wide. These are raised a minimum of 3 metres above the ground on 25mm diameter steel bars. The combined roost square area is 45 square metres and provides habitation for at least 330 bats.
Designs for the Bat Spiral have been exhibited internationally, including ‘Animal Architecture’ exhibition at the Architecture Centre, Houston Texas in 2012. Whilst the model of the Bat Spiral was selected and exhibited at the Royal Academy Summer Exhibition in 2010 curated by architect Will Alsop.