A roof for all creatures
great and small
Richard Bishop, category manager for roof at Wienerberger, talks to RCI about considering vital wildlife
habitats when constructing roofs
Our buildings play an essential
part in providing shelter and
protection for an integral
part of our ecosystem - the
18 species of bats that live in the UK.
Creating roosting spaces for bats is an
important conservation action, as all UK
species are known to roost in buildings,
with some species relying on them more
UK bats don’t construct their own
roosts, so are often reliant on manmade
structures that are already
available to give them a suitable
habitat. There is some concern that
future housing stock won’t be able to
offer adequate roost space for bats,
threatening their survival. With
the architectural trend for airtight
buildings, there are less crevices and
roof access points for bats to utilise.
Therefore, making room for bats in
our buildings is becoming part of
creating eco-friendly homes.
All bats and their roosts are
protected by law, and it is an offence
to deliberately disturb, handle or kill
bats. The potential fi ne for destroying
a roost is £5,000 per bat or six months
in prison. Planning authorities have
a legal obligation to consider whether
bats will be affected by a proposed
development, and this legislation
should be incorporated into their
Taking bats into consideration before
starting any work protects you from
prosecution, whilst also minimising
any costs or delays later down the
line. Having bats doesn’t mean that
building work, roof repairs, pest control
or timber treatment cannot take place,
and your local SNCO (Statutory Nature
Conservation Organisation) can advise.
Non-invasive checks into roost areas
can be done without needing a licenced
bat worker, but closer checks and work
on a roost should be completed by a
Natural England EPS licenced worker.
Bats often use roof areas to shelter,
but different bat species require
different kinds of spaces during the
year, preferring a warm space in the
summer to rear their young and a cool
space in winter to hibernate.
Pipistrelle bat species will rarely
enter a roof void, but will use building
features such as soffi ts, fascias, hanging
tiles, gaps between roof tiles, roof lining
and lead fl ashing for shelter.
Brandt’s bats and whiskered bats
are also crevice-dwellers, but may
enter roof spaces to fl y around.
These crevice-dwelling bats only
require a small 15-20mm high gap to
crawl into their roost.
Long-eared bat species prefer
older buildings and will occasionally
roost in the open within the roof void.
Horseshoe bats use buildings during
the summer months, but as they are
poor crawlers they need roof spaces
with easy fl ight access rather than bat
Bat boxes are suitable eco-habitats
for some species of bats. They have
the advantage of offering a permanent
space for bats that requires little
maintenance and has good thermal
properties. Bat boxes can be made from
brick, featuring a plinth detail at the
bottom to allow bats to enter and exit.
They can be integrated into the façade
of the building, using the same brick or
installed retrospectively. Bat boxes can
be opened at the rear to allow access
into roof cavities or roof spaces, or they
can be embedded so they don’t impair
the airtightness of the building.
Bat boxes should be placed as close
to the eaves or a gable apex as possible,
at least 4 metres off the ground and
away from windows, door and wall
climbing plants to keep the inhabitants
safe from predators.
Roof tiles can also create eco-habitats
for bats. Slightly raising roof tiles by
putting a small amount of mortar at the
bottom of a tile to lift it up (by 20mm
x 100mm), spacing two adjacent tiles
slightly apart, cutting a small section
out of ridge tile or placing a ridge tile
on top of two neighbouring tiles are all
simple ways to give bats access through
small gaps whilst preventing rainwater
ingress. Modifi ed access roof tiles are
also available as a more aesthetically
pleasing and subtle option. The right
amount of access or raised tiles should
be installed to ensure conditions are
suitable for bats; too many and the
temperature of the space will alter, but
too few and bats may get trapped inside.
To encourage the industry to
create habitats for British wildlife,
Wienerberger offers bat and bird boxes
and access tiles in a variety of styles.
o ers bat and
bird boxes, as
well as access
tiles in a variety
94 www.rcimag.co.uk November 2018