Construction material is
material used in the construction industry to create buildings and structures,
e.g. steel, timber, aggregates, plaster, concrete and plastic products as well
as manufactured products. The pressures and impacts related to the various life
cycle stages of construction materials can differ significantly. For metals,
for instance, the mining and refinery stage is often very energy intensive,
causing fossil-fuel-related emissions. In the use phase, impacts depend very
much on the specific application of the material. Dissipative emissions of the
material itself occur, for example, in the case of corrosion of surfaces
exposed to weather, or in the case of inherently dissipative applications such
as spraying paints. These emissions can be attributed to the material itself.
Further emissions in the use phase are related to maintenance and upkeep but
mostly to the energy consumption of products. Materials also influence product
lifetimes and hence the need for replacement production. The attribution of
environmental impacts to materials in the use phase is problematic, as materials
are incorporated into products (i.e. buildings) and it is the products that
provide functionality. However, the analysis of alternative designs that use
different materials can provide an indication of the environmental implications
of material choice. In houses, for instance, the use of extra insulating
material provides even higher energy savings. In many cases, however, energy
requirements in the use phase do not depend on the material. In such cases the
connection with materials is lost. Thus, positive as well as negative impacts
of materials should be assessed throughout their life cycle. In waste
management, the main issue is the large difference in end-of-life options.
Recycling is common for metals, while most bulk construction materials end up
in landfill.
THE ABC FOR SUSTAINABLE CITIES
UNEP / UN HABITAT / FIDIC / GI-REC
