Transcript Slide 1

Sustainability in Non Domestic
Construction
By Professor Christopher Gorse
– licensed under the Creative Commons Attribution – Non-Commercial – Share Alike License
http://creativecommons.org/licenses/by-nc-sa/2.5/
Sustainability in Non Domestic
Construction
Professor Christopher Gorse
Approximate estimates on
energy use
• Buildings are responsible for 50% of the
energy currently used in the UK. With the
increased emphasis on reducing carbon
emissions and energy demands, buildings
must become more efficient.
Currently we are not particularly good at designing
and constructing low carbon buildings
Discrepancy in Measured v’s Predicted Mean U’values for New
Build UK Dwelling (Wingfield et al. 2011)
Discrepancy in Performance
• The following graph shows the expected
designed heat loss of buildings compared
with the actual heat loss. Some of the
buildings in this study lose almost twice as
much heat energy that they were designed
to lose.
Wingfield, J., Miles-Shenton, D. and Bell, M. (2011) Comparison of Measured versus Predicted Heat Loss for New Build
UK Dwellings – Unpublished Data, Leeds Metropolitan University, Leeds, UK
Comparison of measured versus predicted heat loss for New Build UK
Dwelling (Wingfield et al. 2011)
Sustainable? Zero Carbon
Government targets!
• Domestic buildings should be zero carbon
by 2016
• Non-domestic buildings should be zero
carbon by 2019
• New buildings only account for 1%?
Zero Carbon
• Commercial and Industrial buildings are
expected to be Zero carbon by 2019.
• The results on the previous graph which
offers the most comprehensive data on
small dwellings does not look positive. If
we are so far away from the target with
domestic buildings can we expect to
achieve zero carbon commercial buildings?
Consider the Impact on the
Environment if we don’t change
Global warming models
Look at the met office site and the
models of global warming
http://www.metoffice.gov.uk/research/hadleycentre/models/modeldata.html
The increases in Carbon concentrations are
greater than the human race has ever seen
and are rising.
www.metoffice.gov.uk
Are the measures being used to
improve commercial buildings
sufficient?
Look up the sustainability checklist for developments
published by the BRE. What issues does it cover?
Building Research Establishment (BRE 2002)
published a guide to assist developers when identifying
sustainability issues.
Issues include:
•
Land Use, Urban Form and Design
•
Transport
•
Energy
•
Impact of individual buildings
•
Natural resources
•
Ecology
•
Community
•
Business
What is BREEAM?
BREEAM
Building Research Establishment Environmental
Assessment Model
BREEAM provides a numerical weighting
system that is applied to new and existing
buildings to assess their ‘sustainability’.
www.breeam.org
BREEAM Categories and
weightings
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•
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•
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Management
Health and Welfare
Energy
Transport
Water
Materials
Land use
Pollution
15%
15%
13.6%
11.4%
5%
10%
15%
15%
Trained assessors score
category
• The BREEAM assessor awards a
numerical score to each category and the
scores are totalled to give an overall
rating.
• The designated BREEAM ratings of pass,
good, very good or excellent can be
awarded.
Minimum score required to achieve
BREEAM rating
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•
•
•
Pass
Good
Very Good
Excellent
25
40
55
70
What are the costs of a
BREEAM Excellent building?
Capital cost of sustainable construction – one model
‘The
Price of Sustainable Schools’ – BRE (2008) – The following is
for a Secondary School:
Low Carbon – Zero Carbon
Buildings
What are the practical solutions to
improve the energy performance of
a building?
Improved thermal performance
•Preventing cold bridges
•Insulating
•Using thermal mass
Improved Airtightness
Air leakage reduces thermal effectiveness
Air gaps cause real problems. If air is allowed to
move around insulation thermal bypass occurs –
cavities should be sealed and air-barriers
maintained.
Harnessing Solar Power
Solar Photovoltaics can be used to harness the
sun’s energy. Energy is collected during
daylight hours and can be used of fed directly to
the national grid.
Buildings that use electricity during the day, such
as offices and schools have the greatest
potential to make direct use of the electricity
generated during the day.
• To capture energy from the sun, solar
panels should face south in the UK and be
orientated at an optimum angle (30-40
degrees).
• The panels should be unobstructed by
trees, building or other tall objects that
may reduce the efficiency.
• Solar thermal panel – solar collectors
capture the suns heat energy. They are
used to assist with the heating of the
building.
Wind power
Natural ventilation reduces the
demand on air conditioning
systems
Ground air heat pumps can supply
additional heating and cooling to a
building
www.heatpumps.co.uk/thebasics.htm
Brainstorming topic
Identify other methods of
improving the energy efficiency
of buildings