“Living Walls” Can Reduce Heat Lost From Buildings by Over 30%
By UNIVERSITY OF PLYMOUTH
Retrofitting an existing masonry cavity walled building with a
green or living wall can reduce the amount of heat lost through its structure
by more than 30%, according to new research.
This one is at the Smithsonian
The study, conducted at the University of Plymouth, centered
around the Sustainability Hub –
a pre-1970s building on the university campus – and compared how effectively
two sections of its walls retained heat.
Despite being on the same west-facing elevation, one of those
sections had been retrofitted with an exterior living wall façade, comprised of
a flexible felt fabric sheet system with pockets allowing for soil and
planting.
After five weeks of measurements, researchers found the amount of
heat lost through the wall retrofitted with the living façade was 31.4% lower
than that of the original structure.
They also discovered daytime temperatures within the newly-covered
section remained more stable than the area with exposed masonry, meaning less
energy was required to heat it.
The study is one of the first to ascertain the thermal influence
of living wall systems on existing buildings in temperate scenarios and was
conducted by academics associated with the University’s Sustainable Earth
Institute.
Writing in the journal Building and Environment, they say while the concept is relatively new, it has already been shown to bring a host of benefits, such as added biodiversity.
However, with buildings directly accounting for 17% of UK
Greenhouse Gas Emissions – and space heating accounting for over 60% of all
energy used in buildings – these new findings could be a game-changer in
helping the UK achieve its net-zero commitments.
Dr. Matthew Fox, a researcher in sustainable architecture and the
study’s lead author, said:
“Within England, approximately 57% all buildings were built
before 1964. While regulations have changed more recently to improve the
thermal performance of new constructions, it is our existing buildings that
require the most energy to heat and are a significant contributor to carbon
emissions. It is, therefore, essential that we begin to improve the thermal
performance of these existing buildings if the UK is to reach its target of net
zero carbon emission by 2050, and help to reduce the likelihood of fuel poverty
from rising energy prices.”
The University is renowned globally for its research into
sustainable building technologies, and this study’s findings are already being
taken forward as part of the University’s Sustainability Hub: Low
Carbon Devon project.
Supported by an investment from the European Regional Development
Fund (ERDF), the three-year £2.6 million program is exploring low carbon
solutions through research and support for local enterprises.
Specifically, this aspect of the project is looking to optimize
the performance and sustainability of external living walls in sustainable
building design through research on the thermal properties, and carbon sequestration,
offered by different plant and soil types.
Dr. Thomas Murphy, one of the study’s authors and an Industrial
Research Fellow on the Low Carbon Devon project, added:
“With an expanding urban population, ‘green infrastructure’ is a
potential nature-based solution which provides an opportunity to tackle climate
change, air pollution and biodiversity loss, whilst facilitating low carbon
economic growth. Living walls can offer improved air quality, noise reduction
and elevated health and well-being. Our research suggests living walls can also
provide significant energy savings to help reduce the carbon footprint of
existing buildings. Further optimizing of these living wall systems, however,
is now needed to help maximise the environmental benefits and reduce some of
the sustainability costs.”
Reference: “Living wall systems for improved thermal performance
of existing buildings” by Matthew Fox, Jack Morewood, Thomas Murphy, Paul Lunt
and Steve Goodhew, 3 November 2021, Building and Environment.
DOI:
10.1016/j.buildenv.2021.108491