The political focus on global warming has tended to reduce the importance architects attach to protecting biodiversity. Yet the impact architecture has upon ecosystems, both at the building and further afield, is enormous. Architects impact upon biodiversity in five main ways:
- Decisions regarding roofs, walls, landscape
- Materials used in construction- their sourcing, assembly and disposal
- Resources needed to sustain buildings in use (energy, water etc)
- Adverse affects of buildings in terms of air and water pollution
- Conservation and rehabilitation of existing structures.
These can be considered in isolation or as a system of inter-connected factors.
Unfortunately for biodiversity, the building regulations, planning system and EU law were traditionally relatively silent - certainly compared to energy and water conservation. However, the EU Habitats Directive has considerable teeth especially after the UK Habitat Regulations which came into force in April of 2010. Known as the Conservation of Habitats and Species Regulations, they place nature conservation squarely within the planning system. The regulations also introduce new offences which could inadvertently be committed by architects engaged in restoration projects. A key area here is the protection of bats and bat roosts (even if they are not occupied). The new legislation is wide ranging and besides roof work, architects should be aware that old trees often harbour bats. There is much advice available from groups such as the Bat Conservation Trust (www.bats.org.uk 
) but if in doubt architects should consult with the local planning authority and commission their own bat survey.
Architects could see the new regulations as an opportunity to connect architecture and nature just as Edwin Lutyens did a century earlier. He created bat and owl boxes within his roofs and gables, believing that they played a part in creating a more ecological architecture. Besides bats other species which inhabit buildings for breeding cannot be recklessly destroyed such as swifts, swallows and house sparrows. The new legislation as well as the Wildlife and Countryside Act provide an ever increasing level of protection.
Buildings and cities have a surprisingly big impact upon habitats and the many vulnerable species that they contain. These impacts are often far way and hence are easily ignored or subject to 'greenwash' standards (as in timber sourcing). Also many of the impacts are insidious such as polystyrene beads and plastic fragments which end up choking our rivers and killing marine life. These are often the result of packaging from the building site. Biodiversity is the Cinderella of the green movement in architecture.
Urban water drainage, Malmo, Sweden. © Brian Edwards
Biodiversity is defined as having three main levels. It is concerned with habitats (wetlands, rainforests, coral reefs); individual species (bat, bird, plant, insect etc); and genetic diversity within species (this is why genetic modification matters). Although architecture does not traditionally concern itself with such matters, the growth of sustainability as an ever-expanding set of global narratives and EU regulation exposes building design and construction to the close scrutiny of the biodiversity movement.
Some architects have already started to fill in the gap in our knowledge and sought to influence practice. The 'cradle to cradle' idea owes much to an understanding of ecological systems, taking principles from nature and applying them to buildings. Similarly the 'biomimicry' design movement and such initiatives as bioclimatic skyscrapers promoted over a decade ago by Ken Yeang have a clear commitment to addressing biodiversity. But beyond the formal adoption of ecological principles to design methodology, biodiversity needs a little more attention in everyday practice, especially after the 2010 Habitats Regulations.
Nature affects us culturally and spiritually and provides the basis for most of our food, medicines, fibre, construction materials, fresh water and even energy. According to Ban Ki-moon, the UN Secretary General, the 'conservation of biodiversity makes a critical contribution to moderating the scale of climate change and reducing its negative impact by making ecosystems (including human societies) more resilient'. By linking climate change and biodiversity there is a new agenda for architecture - one that promises more richness and beauty than buildings intent merely upon reducing their carbon footprints.
One of the key drivers for the loss of global biodiversity is building development. There is insufficient attention paid to integrating biodiversity policies with strategies for urbanism. Infrastructure development, mass housing and social programs generally pay scant regard to connections between biodiversity and human well-being. This is an area where knowledge is poor and action thin on the ground beyond a few token projects.
A recent UN report titled Global Biodiversity: Outlook 3 calls for better 'communication, education and awareness raising' around the topic of biodiversity. It seeks to influence the indirect drivers (such as architects and the construction industry) as well as the direct drivers such as fisheries, forestry and agriculture. Biodiversity is becoming a core issue for many of today's major economic sectors and is increasingly a heading in policies for corporate environmental responsibility - hence it will impact upon how companies commission their buildings.
Besides the links between strategies for global warming and biodiversity which have found their way into recent international agreements, another change is the move away from the pocket approach to habitat protection to that of linear systems. The latter is driven by the need to establish migration corridors whereby species can move across urban areas and through the world's expanding deserts as global warming bites. Such corridors are often based on inland water systems and in Europe involve much habitat creation on former brown field land. Building in or adjacent to such corridors can do much to support local and often also global biodiversity.
European initiatives
Initiatives in Europe are increasingly taken by the European Environment Agency (EEA), based in Copenhagen. It has targeted three key areas - coastal regions, forests and urban areas. The latter has been ignored politically for some time but the EEA has brought the links between nature, cities and architecture to the fore. It is particularly keen that regional movement barriers are overcome so that species can change their location according to climate change. Re-location with stepping stones through urban areas is critical for the survival of many of Europe's species of plant, insect, bird and bat. Climate change and heat island phenomena makes new thinking necessary on the structure and ecological function of urban areas from big sites to domestic roofs and building facades.
In its report 10 messages for 2010: Urban ecosystems the EEA argues that 'mastering the challenge of urbanism' holds the key to 'maintaining biodiversity and quality of life'. It states that urban design provides the framework for the effective use of land, allowing greenery and biodiversity to penetrate the city. With good design, urban areas can provide opportunities, not merely threats, to ecological diversity. Urbanisation, it argues, is an opportunity to green the city and the higher the building density, the greater the space which can be left for nature. These corridors of biodiversity based often on urban wetlands, allotment gardens, cemeteries, botanic gardens, parks and roadside trees can be linked into a network of planted roofs, balconies and whole facades, thereby creating a 'green' city. The habitats formed provide habitat niches for specialist species such as black redstarts. In fact, half of Europe's capital cities (including London) contain one or more species which are on Europe's endangered list with Berlin, noted for its greening policies, containing 15.
Bees are a good measure of biodiversity and one of the areas of current global concern. However, the colony of bees on the roof of the Paris Opera produces almost 500kg of honey a year. Although air pollution in cities is greater than rural areas, there are lower levels of pesticides allowing the urban bees to outperform their country cousins. Potentially, urban planting can produce high levels of ecological richness and provide the kind of biological robustness and beauty lacking in farmed landscapes.
Action points for creating biodiversity as part of architecture:
- Establish ecological baseline and strengthen this
- Create habitat opportunities as part of the development process
- Leave wasteland and dead trees alone
- Seek to link habitats on the site with those further afield
- Use water as the biological driver, exploiting grey-water and SUDS
- Provide an opportunity for humans and nature to interface
- Avoid over-trimming grass or hedges (establish wildflower areas)
- Protect what is inherited.
Biodiversity, quality of life and global warning are directly connected. Architects have a key role to play alongside their actions to reduce energy consumption. However, unlike CO2 emissions, the science and knowledge of biodiversity in a building context is less well developed. The choice between steel, concrete, masonry or timber construction is complex from an energy point of view let alone the ecological impacts from cradle to grave. Yet society is moving towards a richer understanding of sustainability where green roofs, planted facades and construction materials from recycled waste or bio-crops are not just emblems but serious attempts to address ecological diversity. The failure to achieve lasting carbon emission targets at COP15 has shifted the green focus onto biodiversity and here architects need to become the new design leaders as protectors and creators of biodiversity.
However, integrating nature and architecture within the building is by no means straightforward. Besides the obvious maintenance costs, a living façade may well obstruct daylight through windows (thereby adding to energy use). Nature is dynamic whilst architecture is static: the two systems are in conflict unless attention is paid to zones and layers. Typically a planted façade needs its own sub-frame forward of the building line with integrated irrigation. A planted roof is also best conceived as another sheltering layer, one that mediates between the external and internal climate. In spite of these difficulties recent examples are pointing to a fresh approach to sustainability and one which carries a great deal of public support.
