The purpose of this blog is to create a detailed resource for people who need to create standalone buildings for bats, often called bat barns, bat buildings or bat condos. Such buildings are often required to replace large roosts of bats that are using buildings that need to be demolished or renovated, usually to make way for new housing, new roads or barn conversions.
Bat buildings replace rarer bat roosts, which include breeding colonies of bats but also small numbers of rarer bats.
Basics
The new bat building can take several forms, but the main thing all buildings have in common is a large uncluttered roof void, usually within a single gable. The building can be multi use, so can be a roof void above something like a wood store as shown in the example below or in certain circumstances the building may also need a ground floor and/or cellar that can also be used by bats. Too much disturbance is a no-no, so if the ground floor space is usable, then using the building for storage is probably acceptable, but a noisy workshop would be detrimental. The entrance to the building for bats takes two forms, either a large opening in the gable as shown in the picture below or via a ‘lead arch’ fitted between the tiles. Usually buildings are fitted with two entrances in case one gets blocked.
A simple bat building, which consists of roof void above a wood store. Cost: approximately £8,000.00
Materials
Buildings can be made of all sorts materials to match existing buildings, or can be creative and bespoke. Buildings can be brick, wood, masonry, rendered and painted etc. Roof coverings are also variable, but the preference is for natural materials, such as clay tiles or slates. Another important thing to note is that Modern Breathable Roofing Membrane (BRM) cannot be used in bat roosts because it can cause entanglement and death of bats. Instead, traditional slaters felt, sometime know as type-1f felt, must be used.
Bat barn with ground floor and loft space roosting areas. Cost: approximately £20,000.00
Size
Size of buildings is crucial for them to be successful and although we have created lots of different sizes over the years, most are square or rectangle with a minimum width and length of 4-5 m and a roof height of approximately 2-3 m, but may need to be much bigger for large colonies of horseshoe bats.
Position
The position of the new building is also important and bearing in mind that bats need to be able to fly freely to and from the building, bat buildings need to be constructed near to trees or hedgerows or other boundary features. Bat buildings amongst buildings or large areas of concrete are unlikely to work. Orientation of the building can also be important and generally speaking, bat buildings need to have ridges that face south to gain the sunlight; similarly bat buildings that are overshadowed on the southern elevation by dense trees tend to be less successful.
Cost
Cost-wise, buildings vary depending on size, materials and use. Examples that we have worked on over last few years range from £7-8,000.00 for wood store-type building as shown above, which had some DIY input, to approximately £20-30,000 for more complex buildings.
Call 01761 233414 and ask for Alex for more information, or email alex@crossmanassociates.co.uk.
