Built Structures
Introduction
London's wildlife depends not only on green spaces, but also on the artificial fabric of the city: houses and offices, factories and warehouses, bridges and car parks, wharfs and jetties, masts and chimneys. Indeed, some species are almost wholly confined to built structures, or spend a significant amount of their lives in, on or around them. Examples include bats, swift, house martin, jumping zebra-spider, London rocket, and maidenhair spleenwort. It is important that the management of existing buildings in London takes account of wildlife, and that new development is built with biodiversity in mind.

Although new development should avoid building on or damaging important sites or populations of species as a first principle, biodiversity can be incorporated into developments through wildlife-friendly landscaping, installation of sustainable drainage schemes, and features such as green walls, balconies and roofs, and nesting and roosting spaces. This is 'designing for biodiversity'.

Designing for biodiversity can, if undertaken in a planned manner, bring about benefits to wildlife. It can also offer developers the chance to secure planning approval more easily, engage the support of local communities, demonstrate corporate social and environmental responsibility, and achieve a unique selling point for the development. In many cases, there may be financial savings compared with a traditional landscaping approach. Users and occupiers of buildings can be provided with animated or diverse landscapes, and may benefit from the environmental benefits provided by SuDs, insulation, etc. Wildlife benefits from having features and habitats that are intentional rather than incidental.

Strategic frameworks
At a strategic level, there is now recognition, albeit limited, of the relevance of built structures to biodiversity conservation, and the potential they have for supporting biodiversity. The biodiversity strategy for England makes specific reference to the need to '[incorporate more] biodiversity elements into green buildings', and uses the 'green roofs for black redstarts' work in the capital as a case study. The Mayor's Biodiversity and Energy Strategies both encourage the installation of green roofs, walls etc. as part of good, sustainable design practice. The Energy Strategy (Proposal 15) ' ...requires planning applications referable to [the Mayor] to incorporate passive solar design, natural ventilation, bore hole cooling and vegetation on buildings where feasible. Boroughs should expect the same.'. This is backed up by London Plan Policy 4A.7.

Design for Biodiversity
Design for biodiversity should consider the ecological function of a built structure in its local context. This requires not only the consideration of how a built structure can minimise any adverse impact upon the local ecology, but also a consideration of whether the built structure or its landscaped environment can deliver any wider ecological benefits or enhancements.

Planning policies (through PPG9) provide for the minimisation of damage to biodiversity by new development, through identifying important wildlife sites (such as the Sites of Importance for Nature Conservation) adopted in local Unitary Development Plans. Legislation (e.g. the Wildlife & Countryside Act 1981 (as amended)) provides the means to protect a range of species during the development and construction process (see the Generic Action Plan).

However, there is evidence that more work is required to assist developers, planners and construction workers to ensure development minimises its adverse impacts and maximises the benefits to biodiversity. Appropriate good practice processes, guidance and tailored advice have emerged within the past 10 years, with a particular focus on the development and construction sector, but more is required.

Supplementary Planning Guidance (SPG) is currently being prepared in a number of boroughs on sustainable and/or 'green' buildings. However, specific features to benefit biodiversity are often simply referred to, without further details. Comprehensive SPG is being prepared by the GLA to complement the Mayor's London Plan on sustainable design and construction, which is due for consultation in 2004.

The Partnership (through English Nature and the Greater London Authority) has worked with the London Development Agency to produce the Design for Biodiversity brochure, launched by the Mayor in February 2004. Accompanying this brochure is an internal toolkit for the LDA, which aims to help their land and property team take full account of biodiversity in their work. The Partnership is also maintaining contact with the Building for Nature project, an initiative being run by the South East of England Development Agency. This is working with house builders in preparing guidance and good practice case studies.

The Construction Industry Research & Information Association (CIRIA) has published Biodiversity Indicators for Construction Projects, as part of a suite of environmental indicators. CIRIA are now developing a similar project around buildings for biodiversity, with a number of partners on the steering group. This project will deliver the technical specification and guidance necessary to install vegetation on buildings for biodiversity, sustainable urban drainage and energy efficiency benefits. The Chartered Institute for Water and Environmental Management (CIWEM) are to publish a book Habitats in 2004 which features a specific chapter on buildings.

Boxes and other external features
At a simple level, nest and roosting boxes can be easily incorporated in or onto existing and new buildings. A wide range of boxes to benefit birds, bats and some invertebrates are now available, and for some species (e.g. peregrine falcon) a programme of installation is being undertaken by partners. There are also opportunities for incorporating artificial void structures (burrows) in walls and embankments of civil engineering structures to benefit species such as sand martin and kingfisher. The viability and performance of bird and bat boxes is not known, although the latter is subject to current research by the Bat Conservation Trust. Guidance as to how best to use these to maximise biodiversity, however, is not readily available, and the opportunity exists to bring this together to benefit developers and planners in London.

London green roofs
London has a number of green roofs which have attracted particular attention. In certain conservation hotspots such as Deptford Creek (in respect of black redstart), local people have been working hard to establish innovative green roofs for biodiversity. The Laban Dance Centre, winner of the Stirling Prize for Architecture 2003, has an aggregate-based roof created for black redstarts from the building rubble on site. The Creekside Education Trust building has a similar roof and many other environmental features.

The substrate-based roof approach, developed in parallel to similar models in Switzerland (where strong research links have subsequently been made), has given impetus to looking at the biodiversity potential of green roofs across London and the UK. The Partnership has been influential in raising biodiversity as a crucial consideration for green roofs, and advocating the need for different approaches and systems that are currently available on the market. Most of these latter accord, at least in principle, to the German FLL guidelines, which do not specifically take biodiversity into account for either their design or on-going maintenance.

The value and potential of green roofs for biodiversity has only recently been recognised through recent research. Further work is currently being undertaken, as well as efforts to prepare specifications to ensure that green roofs maximise their potential for wildlife. Representatives of the Partnership have advocated these issues at a number of conferences, and have made links to manufacturers, developers, and researchers in the UK, Europe and North America, and other BAP partnerships in the UK.

Links with London Biodiversity Action Plans
London's priority habitats and species are influenced by built structures, and some depend on them for their existence. All plans should identify how, if possible, to incorporate a built structure element into the delivery of actions.

Some Habitat and Species Action Plans are particularly relevant: Tidal Thames, Wasteland, Chalk Grassland, Bats, Black Redstart, Sand Martin, House Sparrow, Grey Heron, Peregrine Falcon. For others, such as Woodland and Heathland, the opportunities and threats that may arise need to be acknowledged.

Objectives, Actions and Targets

Objective 1: To encourage developers, architects, designers, planners and others to design for biodiversity.

Target: To hold a London green roof conference in 2004 and to produce technical specifications for designing buildings for biodiversity by 2005.

Objective 2: Collate evidence on the biodiversity benefit of green roofs, walls and other approaches to designing for biodiversity.

Target: To publish well-evidenced research report about the biodiversity benefits of green roofs by 2006.

Objective 3: Promote the existing and potential biodiversity conservation value of built structures.
Target: Ensure two 'biodiversity on buildings' events become part of annual programme of education and awareness raising campaigns.

References
• Brenneisen, S., 2001, Vögel, Käfer und Spinnen auf Dachbegrünungen – Nutzungsmöglichkeiten und Einrichtungsoptimierungen, Geographisches Institut Universität Basel and Baudepartment des Kantons Basel-Stadt.
• City of London and British Council for Offices, 2003. Green roofs; research advice note, BCO.
• DEFRA, 2002, Working with the grain of nature; a Biodiversity Strategy for England, The Stationery Office Limited.
• EcoSchemes Ltd, 2003, Green roofs: their existing status and potential for conserving biodiversity in urban areas, English Nature Research Report 498, English Nature.
• FLL, 1995, Guidelines for the Planning, Execution and Upkeep of Green-Roof Sites (English version), Forschüngsgesellschaft Landschaftsentwicklung Landschaftbau e. V., Bonn.
• Johnston, J. and Newton, J., 1993, Building Green; A guide to using plants on roofs, walls and pavements, London Ecology Unit.
• Jones, R. A., 2002, Tecticolous invertebrates: A preliminary investigation of the invertebrate fauna on ecoroofs in urban London, English Nature, London.
• Kadas, G., 2002, Study of invertebrates on green roofs: How roof design can maximise biodiversity in an urban environment, unpublished MSc thesis, University College London.
• London Development Agency, et al., 2003, Design for Biodiversity; a guidance document for development in London, LDA.
• LDA Biodiversity Toolkit
• Mayor of London, 2002, Connecting with London's nature; The Mayor's Biodiversity Strategy, GLA.
• Mayor of London, 2004, Green light to clean power; The Mayor's Energy Strategy, GLA.
• Meech, H., 2001, Wildlife and Buildings; technical guidance for architects, builders, building managers and others. Manual of Buildings, National Trust.
• Woodall, R, and Crowhurst, D., 2003, Biodiversity indicators for construction projects, CIRIA W005, Construction Industry Research and Information Association.

Abbreviations
AUU - Architecture & Urbanism Unit, GLA
EN - English Nature
GLA - Greater London Authority
LBBF - London Borough Biodiversity Forum
LDA - London Development Agency
LNHS - London Natural History Society
LWT - London Wildlife Trust
RSPB - Royal Society for the Protection of Birds

Contact
Mathew Frith
Peabody Trust
Landscape regeneration manager
Property Asset Management
45 Westminster Bridge Road
London, SE1 7JB Tel 020 7021 4422
Email [email protected]