Biodiversity Enhancements for New Builds

Posted by Sara King BSc (Hons) on 15/08/2011

Biodiversity enhancements are a key element of the masterplanning process and BREEAM assessments, including Code for Sustainable Homes.  Local Planning Authorities also request ecological enhancements to be included within development plans in accordance with Local Plans, Planning Policy Statement 9: Biodiversity and Geological Conservation, and local and UK Biodiversity Action Plans.  

New build designs and construction techniques usually reduce opportunities for roosting bats and nesting birds.  These species use gaps in tiles, soffits, roof spaces and other features associated with traditional building practices (generally undetected).  The requirement imposed on new builds to reduce their carbon footprint has led to a number of changes, including the need for the design to be airtight.  This design is aimed at improving the energy efficiency of buildings, which will benefit wildlife in the long-run; however, if not designed carefully, such design leaves no capacity for bats (and other wildlife such as swifts) to enter roof spaces.

Guidance

A new publication has been produced by Dr Carol Williams of the Bat Conservation Trust detailing advice on incorporating biodiversity enhancements to new buildings. Biodiversity for Low and Zero Carbon Buildings: A Technical Guide for New Build details information on biodiversity features, such as built-in bat and bird features, to be incorporated within low and zero carbon buildings.  Details include access dimensions for specific species of bats and birds, specific roosting and nesting dimensions, aspect, height and construction materials.  The publication also details guidance for the number of roost/nest sites to be incorporated within a development proposal published by the Town and Country Planning Association (2009).  It recommends that around 1 in 20 structures should include roosting opportunities for crevice dwelling species of bats and nesting features for swifts; 1 in 50 structures include opportunities for house martins and swallows; and 1 in 100 for starling nesting features.

Ecosulis can provide site-specific advice in respect to incorporating biodiversity opportunities into any masterplan.  We also have over 20 years experience of habitat creation for bats, nesting birds and other wildlife.

Examples of biodiversity opportunities

Built-in bat roosting features can be included within any new build construction and are designed to be discrete.  Most are self-contained chambers, which do not allow access into the building itself (bat tubes) and require little or no maintenance.  These are built into a new build, and can be covered in cladding or breathable paint to incorporate it into a building design and construction.  Others can be incorporated on the roof of the building to provide access into a roost chamber beneath tiles or though bricks.

Built-in bird nesting opportunities usually include a variety of different self-contained chambers specifically designed for bird species, including swifts, house martins and swallows. Provision for barn owls can also be included within rural buildings or those on the edge of a development. Barn owl features usually include barn owl boxes or specially designed access into a roof chamber.

Planting enhancements using native species are also important to enhance a site to support a range of wildlife, including fruit bearing species, honeysuckle, dog-rose, ivy, evening primrose and night-scented catchfly.  Green roofs and living walls can also be incorporated within development design to enhance foraging opportunities for invertebrates, bats and birds.  

Long-term monitoring of roost and nest sites are important to record their use and to ensure that they are maintained.