In any appraisal of the environmental performance of a product, life-cycle assessment or analysis (LCA) and total embodied energy are key factors to consider.
Basically, LCA means measuring the total impact of a product on the environment.
This includes the impact made during:
- the extraction of raw materials; - the total product life; and - disposal of or recycling at the end of product life-cycle.
Alternatively, total embodied energy is:
- the energy required to obtain the raw materials; - the energy required process and produce a building material; - the energy used in transporting the material (at all stages); and - the energy used in actual construction.
Timber accounts for 50 per cent of the industrial raw materials used in the world. But timber only accounts for four percent of the energy required to convert these raw materials into useful products.
The manufacture of other construction materials. such as steel, aluminium and concrete, consumes vast amounts of our non-renewable resources.
In addition, the process releases large amounts of carbon dioxide into the atmosphere.
Therefore, to manufacture steel, aluminium and concrete, considerably more carbon dioxide is generated when the processes are compared to the manufacture of timber.