Sustainable construction materials

This chapter has explored some of the key issues with respect to the sustainable use of materials in construction. It has identified the need to produce quality buildings that are comfortable and healthy to inhabit whilst being energy efficient and utilizing natural resources to their optimum potential. It has highlighted the need to evaluate the use of materials with a whole life cycle approach considering impacts of using the material from cradle to grave, from initial mining or harvesting to eventual disposal including the potential for recycling at interim stages. Methodologies such as ‘environmental profiles’ and the ‘code for sustainable homes’ are available in the UK to facilitate improvement of environmental standards however, it is necessary for each material to be considered in the context of its location and availability as they will affect the resource depletion and the requirement for transportation. A material that can be used sustainably in one part of the world may not be environmentally benign in another. Local materials generally have minimal embodied transport energy and fast growing renewable local materials can have further advantages of carbon sequestration during their growth period thus reducing their net greenhouse gas emissions. Much scientific research is being undertaken to define the physical properties of local crops such as hemp, straw, date palms and pineapple leaves. Understanding individual materials and the processes they have undergone must be key to the optimal use of the earth’s resources. A re-cycled product may not necessarily be the best environmental option if it has been transported around the world to undergo an energy intensive re-cycling process. As ever the designer must make a decision that will involve compromise in order to optimize the environmental impacts of the building. The decision will also be driven through economic constraints but the selection of sustainable construction materials will benefit from the availability of good data bases and an appreciation of the complex inter-relationships of the individual environmental impacts of materials.