The construction process and building use not only consume the
most energy of all sectors in the UK and create the most CO2
emissions, they also create the most waste, use most non-energy
related resources, and are responsible for the most pollution.
Climate Change
Building use in the UK contributes about 50% of the UK's CO2
emissions and construction contributes about another 7%. The AECB
have shown that the Government figures on energy performance of
houses grossly underestimate the CO2 gains that could be made by
building energy efficient buildings. The main base performance
criteria for energy efficient buildings all concern the thermal
performance of the building shell where most of the CO2 gains can
be most easily made.
The fact is that if we are serious about climate change then we
need to stop playing games with technologies which do not deliver
real CO2 savings. The real challenge in this area is the
refurbishment of existing buildings. However it would help for a
start, if we also produced really energy efficient new
buildings.
Waste
According to DEFRA the waste going to landfill from the
construction industry in 2004 was about 100 million tonnes. This is
more than 3 times the amount of domestic waste collection (28
million tonnes). It has gone up from about 70 million tonnes in
2000. In many situations this is equivalent to one house being
buried in the ground for every 3 built. This is an important
consideration when the embodied energy of a building is being
calculated. Usually such calculations do not take into account an
extra 25% energy for waste. This is obviously more serious for
higher embodied energy products than low embodied energy
products.
There are increasing regulations about waste disposal from
construction and many products, even common products like gypsum
plasterboard and mineral wool insulation are now labelled as
hazardous and require special disposal. In addition there are many
projects to find new uses for waste construction materials (through
Government bodies such as WRAP). However here, as with waste
disposal, the less processed a material is, and the less hazardous,
the easier re-use, recycling or healthy disposal (for example
through composting) will be.
Resource Use
The construction industry is the major consumer of resources of
all industries in the UK. It accounts for 90% of all non-fuel
mineral use, and a large proportion of timber use. Many of the
materials used in the UK now come from abroad, sometimes from
countries where with less environmental control or labour
justice.
As BioRegional and the World Wide Fund for Nature have shown in
their One Planet Living material , if everyone in the world
consumed resources at the same rate as we do in the UK it would
take the equivalent of 3 planets now to sustain this consumption.
As a global community we exceeded sustainable levels of consumption
in the mid 1980s, so both from the point of view of human survival
and of justice and equity, it is not feasible or desirable to
continue at current levels of consumption. It is not possible for
the way of consumption in the UK to be spread throughout the globe,
and as a matter of urgency we and other western nations need to
radically reduce our consumption of resources.
A distinction needs to be made between sustainable and non-
sustainable resources. Sustainable can be divided into renewable
resources (those which can be renewed - particularly those that are
grown in short time cycles such as food and certain kinds of
timber) and plentiful resources (such as clay, chalk, and sand). In
addition materials which can be indefinitely re-used (or recycled
easily) are to some extent sustainable. Non-sustainable resources
are those of which there is a known limited supply, and which
cannot be replaced or easily reused or recycled with minimal extra
energy input. These non-sustainable resources therefore include
many minerals, oil and some timber (which is very slow growing or
where the extraction causes the extinction of the habitat and
therefore of the resource) at our current levels and forms of use.
In the UK the construction industry is the main consumer of
non-renewable resources, as well as a huge consumer of renewable
resources, and this means it must bear greatest responsibility for
addressing this situation, and addressing it quickly.
Habitat Destruction
While the three greatest and most imminent threats to the
survival of our civilisation are global warming, peak oil (the
growing energy gap between supply and demand) and resource
depletion, habitat destruction can have a more immediate and
disastrous effect on certain localised areas and species. Sometimes
these can also have a global impact (for example the impact of the
deforestation of the Amazon rain forests).
It is hard to keep track of the number of species made extinct
every year, and of the further erosion of biodiverse and rare
habitats. It is equally hard to relate this destruction to
construction use in the UK. However the fact that the construction
industry is such a huge consumer of materials, particularly of
imported chemicals, minerals, metals and organic materials such as
timber, inevitably means it has a huge impact and obviously has the
greatest impact of any sector in the UK, on habitat erosion and
destruction globally.
Many essential materials are now in short supply. These include
materials such as copper, which is largely mined in South America
where whole mountains have been taken down and landscapes altered
in the search for ever more rare resources. They include materials
like Titanium Ore which is used for the production of Titanium
Dioxide, which is one of the main ingredients of paint among other
things. This is often mined in rare habitats such as Madagascar
with consequential and inevitable dangers to the ecology .
Of course it is possible to mine and extract materials from
habitats without destroying them. However there will always be
consequences to this benign form of extraction in terms of cost,
speed and quantity. It is therefore imperative that we radically
reduce our demand on such materials in order to allow this process
to happen benignly. At present the whole world is heading in the
opposite direction, and we will lose huge areas of unique habitat
forever in the coming years unless we change the way we consume
such materials. This is particularly as regards how we build. It
means using less of these materials by building more simply, with
more local and plentiful (ie sustainable and renewable) materials
and with less waste.
Pollution
Finally the environmental impact of construction is also felt in
terms of pollution. This is not in the extraction but in the
processing of materials for construction. And again, not
surprisingly, the construction industry has the biggest effect of
all sector because of the quantity of materials used in
construction
In the past there was a simple general equation between the
amount of pollution and the amount of energy in a process. On the
whole the more energy required, and the more processes, the more
waste and the more pollution was generated. Processes such as the
processing of plastics for PVC, PU and PI, the manufacture of
Titanium Dioxide, the galvanising of metals were all very
polluting. Much of this is now controlled by legislation and
pollution of air, land and sea within the European Union and many
Western Nations is now reducing. However we have also exported a
lot of our pollution in the outsourcing of our manufacturing to
non- western nations such as China, India, and areas of South East
Asia and South America. Products may be assembled in the West, but
most of the basic materials and components are often processed
elsewhere. The loss of control of manufacturing processes therefore
has a considerable environmental impact.
As with habitat destruction, it is difficult to track this or
control it. Assessments like BREEAM attempt to assess this effect
but there is a huge lack of data and resource for doing it across
all product lines. What we can do is reduce high energy material
use, and use local and low energy materials as much as possible.
Until there is proper global control of polluting processes or a
clear legislation/ incentives in the UK along with proper
assessment lifecycle assessment of all materials and manufacturers,
we will have to stick to what we are sure of, and also what is
inherently non-polluting.