Reducing the environmental impact of construction by using renewable materials

The relative importance of embodied energy and operational energy on the environmental impact of construction are examined in this article. It highlights the fact that the targets set by the Kyoto Protocol are primarily being met by the reduction of in-use energy, and that the implications of that are that the energy embodied in buildings will increase in signifi cance from its current 17% level to 50% by 2050. The article describes how the use of bio-based renewable materials can make a signifi cant contribution to reducing not only the embodied energy of buildings by using the sequestration of CO2 through photosynthesis, but also in-use energy demand through passive environmental control. Case studies are presented showing ways in which this has been achieved.