Habitat loss doesn’t just affect rainforest dwellers, says Paul Miles. New builds and carbon reducing measures have been tough on the species that share our homes. Here’s how to bring them back

Nothing says summer like sitting outside, watching swifts soaring overhead. Yet these birds, like other building-dependent species such as house martins, swallows, barn owls and bats, are in decline. A major factor in their decline is loss of habitat. As tumbledown barns are converted into desirable homes for humans, barn owls and other birds lose theirs. Newly built homes are airtight with no nooks and crannies, which is good news for reducing carbon emissions but bad news for animals such as bats that rely on such spaces.

Habitat loss is the main threat to global biodiversity and despite much of the debate focusing on rainforests, building sites are equally important. 2011 marks the beginning of the UN’s Decade on Biodiversity, with world leaders being exhorted to slow the mass extinction of species being wrought by 21st century civilisation. In Britain, some bat species have declined by as much as 95 per cent and birds have fared similarly badly. Edward Mayer of Swift Conservation (www.swift-conservation.org) says that recent ‘progress’ in Europe has harmed the birds. ‘Grants for the renovation of the EU countries’ historic towns have led to the wholesale removal of swift (and bat) breeding sites as an unforeseen consequence,’ he says.
Britain’s most common bat, the Pipistrelle, only requires a 15mm by 20mm space through which to enter and roost in a cavity. Once roosting, they, like all British bat species, are protected by law. Professor Brian Edwards, of the Royal Institute of British Architects’(RIBA) Sustainable Futures Group says that, in Britain, the laws, that were amended and renamed last year, have ‘considerable teeth.’

‘Known as the Conservation of Habitats and Species Regulations 2010, they place nature conservation squarely within the planning system,’ says Edwards, holder of a PhD in architecture from Glasgow University. ‘The regulations 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.’ Edwards advises that anyone thinking of restoring or altering old buildings should seek advice from groups such as the Bat Conservation Trust, consult with their local planning authority and consider commissioning their own bat survey.

Understandably perhaps, some homeowners become frustrated that even minor evidence of bats or nesting birds can upset plans, costing time and money. However, if like many nature lovers, you like the thought of sharing your home with other species and by doing so, encouraging biodiversity, there are several ways to do this. German company,Schwegler Natur, manufactures a range of hollow bricks designed as bat roosts and bird nests. In a variety of forms suitable for various species, with interiors designed for the animals’ comfort – think textured walls and open-plan living areas with hanging space to suit all sizes – the prefab roosts and nests can be built into walls or roofs to encourage bats (there are 1,000 species worldwide of which 17 are in the UK) and birds to make their homes with you.

‘The idea is that from inside the house, you wouldn’t know that you share your home with other animals,’ says Dr Carol Williams, author of a book launched last year, Biodiversity for Low and Zero Carbon Buildings. The book, published by RIBA, contains detailed architectural plans showing how feathered friends such as peregrine falcons, barn owls, swifts and swallows plus bats can be accommodated comfortably in modern homes without impinging on human residents. ‘These species have evolved to live with humans,’ says Williams. ‘Now, because of the real need to lower the carbon footprint of buildings, we risk endangering biodiversity by concentrating on reducing emissions. If we do everything for nature except make a home for wildlife, we’re not helping.’ As well as the visual pleasure, wildlife can have a positive impact on our homes. Owls control rodents while peregrine falcons feed on feral pigeons. Bats, house martins and swifts meanwhile, all eat many thousands of insects a day, many of them pests such as aphids and midges. And Williams isn’t just talk either. She asked her builders to make holes in the new fascia and soffits she had fitted to her Cornwall home, in the hope that bats would roost there. They did.

Another way to enhance biodiversity is in the garden. Planting native species provides habitats for native wildlife. In Cumbria, Caroline Langham, owner of Cote How B&B is planting rare touch-me-not balsam as it’s the habitat of the even rarer netted carpet moth. Non-native trees have been replaced with oak and beech, to encourage red squirrels. If you don’t have a garden, you can always plant on your walls or roof. Living walls and roofs have become increasingly common in mainstream architecture and Britain now has the largest living wall in Europe at, of all places, a shopping centre – Westfield in London. As well as providing habitats for insects and birds, living walls and roofs insulate buildings and reduce noise. In an era of climate change and fast urban lifestyles, we need more of them in our cities, says horticulturalist and broadcaster, Professor Chris Baines. ‘Every extra living green surface will help to moderate the urban heat island effect, slow down the rate of rainwater runoff and help to lift the spirits,’ he says. ‘Softer, cooler, greener should be the environmental aim for every built community.’

This holistic approach that bears in mind not just the construction of our habitats but also that of other species, is only just emerging from the ‘alternative’ world and entering the mainstream. ‘It’s unusual for architects, ecologists and engineers to work together to create a built environment that takes biodiversity and ecosystem services into account,’ says Blanche Cameron, joint organiser of a new annual competition for projects that do so. The first Integrated Habitats Design Competition, last year, supported by the government body, Natural England, attracted 40 entries from architectural practices, ecologists and engineers in six countries. The winner, with a plan for converting a disused railway depot into student accommodation, including bat roosts, bird nesting, living roofs, solar panels and more, was a first year architecture student from Liverpool University. ‘The enthusiasm shown by new architects and students is overwhelming,’ says Cameron. In the US, theInternational Living Building Institute, a new NGO formed in 2009, is expanding and complementing existing requirements for certified green buildings, such as those established by the US Green Building Council, to include measurements of species and habitat conservation in order to promote ‘greater ecological benefit.’

One established architect who is already building green properties with such added benefits is Justin Bere (www.bere.co.uk). His new self-designed London home has a living roof of hawthorn and hazel, planted in soil up to 45cm deep, and a wildflower meadow. There is a beehive and bat roosting and bird nesting boxes built into walls as well as all the ‘low carbon’ features that owners of a ‘green home’ would more usually expect, such as solar panels for hot water and electricity.
‘If we put a building over nature we have an obligation to put nature back on top,’ says Bere, talking of his amazingly colourful rooftop flowers and hazel coppice that are all far more diverse than a roof planted with more usual sedums. ‘It doesn’t cost a lot but we can’t live without nature and we don’t have any right to try and do so.’ He has created a space where house sparrows flock to eat aphids on common vetch flowers on his rooftop meadow. ‘I love watching everything – the change of seasons and the wildlife.’ It must all be a welcome sensory feast for his human neighbours too. Previously the site, encircled by tall terraced houses, was home to a sausage factory. London’s feral foxes probably miss that.

Source: Theecologist.org