4
MARCH 2015 PRO INSTALLER
PRO NEWS
www.proinstaller.co.uk
All images
courtesy of
Modcell
Straw ECO
homes could
cut heating
bills by 90%
Research from the University of Bath’s Department of
Architecture and Civil Engineering has resulted in the UK’s first
affordable straw homes going on sale in Bristol last month.
Promising fuel bills up to
90% cheaper than an equivalent brick-built house and
costing less than the average Bristol house to buy, the
new straw houses represent
for the first time an affordable, low carbon and fuel-efficient means of house building.
Previously, straw houses have
been more familiar in fairytales
than as a realistic option for
homebuilders, due to a lack of
certified materials and concerns
about durability. A new factory-built straw panel design developed at the University of Bath has
received BM Trada’s Q mark certification, meaning developers and
house buyers can now insure and
secure mortgages against homes,
schools and offices built using this
sustainable construction method.
The seven Bristol townhouses
were built by developers Connolly
and Callaghan using the innovative 3.2m by 2.9m ModCell straw
panels, in which an engineered
timber frame encloses the compressed straw bale insulation.
Constructed with the load-bearing
straw panels within an airtight
design (plus triple glazed windows) the new houses will need
significantly less conventional
heating. Their super-insulated
straw walls provide three times’
greater insulation than required by
current UK building regulations so
fuel bills are anticipated to fall by
up to 90%.
The Q mark industry certification
is the result of the University of
Bath’s three year, €1.8m EuroCell
research project funded by the Executive Agency for Small and Medium-sized Enterprises (EASME)
jointly with industry partners
Integral Engineering Design and
architects White Design.
To receive certification the University research tested the ModCell
straw panel’s energy efficiency,
fire safety, durability and weather
resilience; including exposing the
panels to heavy rain and extreme
temperatures ranging from 20°c
to 50°c.
Craig White of ModCell commented: “The Q mark industry
certification means that straw is
now a viable, affordable means of
tackling the housing crisis in the
UK. Using a ‘fabric first’ approach
is ideal for private homes, social
housing, and new, innovative projects such as custom-build. Straw
now offers a simple and effective
home-grown solution to the UK’s
housing needs.”
Professor Pete Walker, Head of
the Department of Architecture
and Civil Engineering at the University of Bath, led the University’s research, which previously
entailed building the innovative
prefabricated straw bale building
called the BaleHaus as a test site
in 2009.
Commenting, he said: “The construction sector must reduce its
energy consumption by 50% and
its carbon emissions by 80% by
2050, so radical changes are needed to the way we approach house
building. As a construction material straw is a low-cost and widely
available food co-product that
offers real potential for ultra-low
carbon housing throughout the
UK. Building with straw could be
a critical point in our trajectory
towards a low-carbon future.”
In the UK up to seven million
tonnes of straw remains after the
production of wheat flour, and up
to half this amount is effectively
discarded due to its low value, to
be used as animal bedding. This
‘leftover’ 3.8 million tonnes of
straw could be used to build over
500,000 new homes, as an average
three-bedroom house needs 7.2
tonnes of straw.
As well as utilising an agricultural co-product, straw has significant
environmental benefits. Rather
than releasing carbon dioxide
(CO2) during the process of
producing a building material, as
brick or cement does, it absorbs
CO2 as it grows. As a result, straw
homes have one of the lowest
carbon footprints available, with
many buildings being net carbon-negative.
The many benefits of straw have
seen a steady increase in straw
bale construction around the
world, with buildings to be found
in countries from the USA to
Australia and China and there are
over 200 in the UK. Straw housing developments are currently in
progress in Bristol (the European
Green Capital 2015) and Cornwall, where a ModCell straw panel
design is one of six now available
to home buyers in the UK’s first
custom-build housing scheme.
At the multi-award winning
LILAC straw built co-housing community in Bramley, West Leeds,
residents benefitted from a 20%
lower build cost and 90% cheaper
energy bills than on average in
Leeds, demonstrating the significant savings that straw buildings
can offer.
For more information visit
www.modcell.com