Living Walls and Green Roofs

By Felicity Carus
March 30, 2009

Living walls and green roofs pave way for biodiversity in new building.

Otters could return to urban rivers, bats could roost under bridges, swifts could flock
to office blocks and peregrine falcons soar above cathedrals under
recommendations from the UK Green Building Council

What do the Westfield shopping centre, Canary Wharf and a Victorian museum have
in common? They are all at the vanguard of a move to encourage biodiversity in
buildings that could take on an unprecedented scale if guidelines published
today are adopted.

Under recommendations from the UK Green Building Council (UKGBC) for developers,
planners and policy-makers, Otters could return to urban rivers, bats could
roost under bridges, swifts could flock to office blocks and peregrine falcons
soar above cathedrals. Existing examples of encouraging biodiversity in
buildings include the Westfield shopping centre in west London and its "living
wall" planted with wildflowers, Canary Wharf's assortment of biodiversity
initiatives, and the south London Horniman Museum's green roof, one of the
country's first.

Carol Williams, the chairwoman of the UKGBC task group of biodiversity and
construction industry experts, said the government's target for all new homes to
be zero carbon by 2016 is changing attitudes in the construction industry. "The
construction and property sector has been pilloried in the past for its negative
impact on green space, wildlife and habitat but the industry can actually have
a positive influence on ecological value. If we don't make provision for
wildlife now, then we might not be able to attract it retrospectively quite so
easily," she said.

The UKGBC task group - which included Natural England, the Association of Local
Government Ecologists, Bovis Lend Lease, the Canary Wharf Group, Grimshaw
Architects - recommended 10 ways to encourage and enhance biodiversity in the
built environment.

Just some of the design features which would encourage biodiversity in cities
are specially made nesting bricks built into cavity walls for birds such as
swifts and starlings, or ledges that mimic cliff faces for peregrine falcons
which are attracted to tall buildings. Cathedrals, office blocks in Canary Wharf
and Battersea power station in south London are all known to have housed
breeding birds of prey.

Green corridors will allow other mammals to "commute", said Williams, and
careful lighting and roosting boxes under bridges will allow Daubenton's and
pipistrelle bats to inhabit areas which are ususally too bright for them.

But according to Dave Wakelin of sustainability consultants Hilson Moran, "green
roofs" have the biggest impact on biodiversity in cities, because patches of
roofspace that mimic grassland or shale environments can create their own
ecosystem. Black redstarts, he says, have been attracted back to Canary Wharf by
the shrill carder bee, a ground nesting bee that burrows into the sediments in
the shale in the roof garden at 20 Cabot Tower.

In the City of London, CCTV is trained on peregrine falcons nesting in an office
block so that staff can watch the progess of a breeding pair, as chicks hatch.
Wakelin said this is just one initiative to get office workers more interested
in the "priority" species in their city.

"We see buildings as extensions of green space. They are like fingers of
greenery spreading out between buildings and act as green stepping stones
between bigger areas of green space mean that you haven't got so many barren
spaces left in cities."

Paul King, chief executive of the UKGBC, said: "If done well, new developments
can actually create habitats in which wild species thrive, and which we can all
enjoy. Green roofs, living walls, and good old-fashioned parks and green spaces
in our built environment can make us all feel happier and healthier, and give
something back to nature."

Environment minister Huw Irranca-Davies welcomed the report. He said: "Our
wildlife brings opportunities as well as challenges, and this report
demonstrates how the construction industry can show leadership in recognising
how protecting and enhancing the UK's wildlife can bring economic as well as
environmental benefits."


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