Cosmetics manufacturer Lush wanted to drive down
carbon emissions, reduce waste and improve energy efficiency by
building what it claims is Europe's' first straw cold room for its
fresh creams, shower gels and skincare products. The building,
made from straw and wood, has a much lower global warming impact
than a conventional cold room made from steel, uPVC and expanded
"Straw is a very unused waste product," says Nick
Read, Lush's green manufacturing co-ordinator. "When you look at
the insulation value of straw, you can get the same performance
from it compared to traditional materials, and it's cheaper too.
It can also be composted at end-of-life. We wanted to reduce our
carbon impact in our manufacturing operations going forward and it
was the right material to use."
Nick knew of
Bee Rowan who has decades of experience in straw construction
work. The company chose to use English straw for lower carbon
impact which was sourced from a farm in Milton Keynes.
Hand tools and traditional techniques were
employed throughout the build, including a sharpening horse to
sharpen the wooden hazel pins that hold the bales together. Other
materials used included clay, which was leftover and recycled from
a previous project Rowan was involved in, and eco-paints.
The wall thickness of the room was determined by the width of the
bales while the fabric of the external walls comprises 90%
recycled newspaper and 10% recycled gypsum. The end-of-life reuse
and recovery potential of every material was an important
consideration for the company - once construction was finished,
only 134kg of waste was sent to landfill at a total cost of
"We sifted through all our waste streams by hand to separate them
out and find a use for them where possible," Read explains. Wood
waste, for instance, totalled 1,257kg of which 140kg was used to
feed the company's biomass boilers, 209kg was stored for future
use, and the remainder sent to an organic recycler. There were
also ten 1-tonne bags of leftover straw and leftover clay which
Bee Rowan took to her next straw build.
Project cost stayed within the allocated £36,000 budget and only
went over timescale by a few days due to it being the first of its
type. Being load-bearing brought some additional complications,
mainly from a fire regulation perspective.
"[At the time] because there wasn't a fire regulations test for
load-bearing straw in the UK, it couldn't be given a fire risk
rating," Read explains. "As a result we are probably going to
carry out the fire risk test ourselves - by doing that, we also
give something back to the straw building community as we will
have shared our knowledge and it enables us to carry that through
to future developments."
While the straw bale building isn't expected to bring any
additional energy usage savings compared to a conventional unit,
its global warming potential is a lot lower. The embodied energy
value of straw is 0.24 MJ/kg compared to rolled aluminium (155 MJ/kg),
plastic uPVC film (69.4 MJ/kg), polyurethane rigid foam (101.5 MJ/kg),
steel plate (25.1 MJ/kg) and steel beams (20.1 MJ/kg).