Built Structures

Durham Lowland Priority Habitats
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Built Structures Action Plan

Priority Species: Bats, House Sparrow, Slow worm, Common Lizard, Swifts

1. Identify sites and structures of particular significance or importance to biodiversity
2. Ensure the inclusion of features useful for wildlife in the design of new buildings
3. Raise awareness of the value of built structures for biodiversity

House Sparrow Targets
Vision Statement: To maintain the current distribution and population of house sparrow through the Durham area

Target Type Unit Value
1. To maintain the range of house sparrow in the Durham BAP area. maintain occupied BBS squares 15 squares, 48.4%

Slow Worm Targets
Vision StatementTo maintain and then expand the range of slow-worm

Target Type Unit Value
1. To maintain the range of slow worm in the Durham BAP area. maintain occupied km squares 32

Common Lizard Targets
Vision StatementTo maintain and then expand the range of common lizard

Target Type Unit Value
1. To maintain the range of common lizard in the Durham BAP area. maintain occupied km squares 21

This plan focuses on the opportunities provided to wildlife by structures within the built environment, and our efforts to maximise those opportunities. For the purposes of the plan built structures are taken to include old and new housing and industrial or business premises, transport infrastructure such as bridges, tunnels and culverts, underground mine workings, retaining walls, gabions and drystone walls.

Built Structures can provide a wide variety of micro-habitats which offer artificial alternatives to declining semi-natural habitats. For example a number of plant and animal species that would normally use natural features such as caves, cliffs, hollow trees, rocks and bare ground have adapted to using habitats and structures in the built environment.

Bats use a variety of built structures at different times of the year, including tunnels and bridges, mineshafts and roof spaces.

Birds such as house martin, swallow and house sparrow, use the eaves under building roofs for nestbuilding, whilst some birds of prey such as peregrine falcon, kestrel and sparrowhawk use ledges on tall buildings for their nests. Kittiwakes, famously in the north-east, also use building ledges, and barn owls are named after their preferred man-made nest location.

Amphibians will use damp corners of built structures (or the remains thereof) as refugia, and culverts and drains are often important migratory routes for newts in both urban and more rural areas.

Reptiles such as lizards and slow worms may also use structures such as south facing walls for basking, and there may be hibernating opportunities in or under some of the larger structures such as gabions.

Similarly there are many invertebrates which rely on the crevices and micro-climates provided by stone structures such as drystone walls for basking, hunting and overwintering.

Mortar in walls provides a substrate for a number of plants, including maidenhair spleenwort, Ivy-leaved toadflax, Red valerian and Pellitory-of-the-wall

Species which occupy built structures are clearly vulnerable to losses, changes and disturbances to those structures. At the same time there are opportunities to create new habitat within new and old built structures.


  • Direct loss of habitat through demolition
  • Direct loss of habitat through infilling of land adjacent to retaining walls, or of mineshaft entrances etc.
  • Physical changes to a building’s structure, whether through renovation or repair, can block ingress and egress to/from nesting, roosting or hibernating spaces
  • Chemical treatments for timber protection can repell or directly harm many animals.
  • Cleaning and repair works may disturb animals or destroy valuable plant communities.
  • Lack of knowledge / information about the location of hibernacula or breeding sites for important species will lead to inadvertent losses.