CONSTRUCTION MATERIALS
The following describes some of the environmental considerations which should
be made when using various construction materials. As stated on the front page,
the choice of materials is rarely simple, with value judgements required at all
stages. It is rarely a case of X is bad so we will use Y because Y will have
negative effects also. Organisations such as BRE (Building
Research Establishment) in the UK have done considerable research on
environmental issues of a wide range of building products and materials, and
have published an environmental profiling system ("The Green Guide").
Factors considered include toxic pollutants during manufacture and combustion,
primary energy used in extraction production and transportation, oil feedstock
consumption, emissions of CO2, VOCs, NOx and SO2,
resource use, resource depletion, waste generated and recycling (% recycled
materials used, % capable of recycling % currently recycled and energy required
to recycle). Each product tested was rated as A, B or C in each of the above
categories, where A is best, allowing comparative judgements to be made.
The assessments were made based on a 60 year life of the structure and included
initial construction, planned maintenance and replacement over this period but,
other than recyclability, the decommissioning aspects were not considered. Some
construction materials in use today, and more so in older buildings, are not
easily recyclable nor are they biodegradable, so it is important that decommissioning
is given further consideration. Also, to achieve an overall rating for each
product, qualitative weightings were given to each factor, with CO2
emissions, primary energy consumption and oil feedstock consumption accounting
for 57% of the weighting, compared with only 6.2% given to toxic pollutants.
This does, however, reflect current UK government policy of reducing carbon
emissions. While this is important, particularly in respect to Global Warming,
it masks many other issues.
Even if the Green Guide is only used to help reduce carbon emissions, it is a
good start. The linked articles below attempt to give a balanced view on all
the environmental impacts. As many impacts are subjective in their severity I
may have omitted or understated some and overstated others. If anyone has
something to add, feel free to contact
me and I will consider adding to or revising the articles.
CONCRETE |
STEEL (STRUCTURAL) |
NON-FEROUS METALS |
MASONRY |
TIMBER |
GLASS |
METAL CLADDING |
INSULATION MATERIALS |
SEALANT MATERIALS |
PAINTS, COATINGS AND FINISHES |
ASPHALTS |
Linked articles are not yet complete for all the topics listed above. More topics will be added to the list in due course, but please be patient.
If you
want added to a mailing list to inform you of updates (around once or twice a
month) please contact
me.