ABSTRACT

Over recent years there has been a growing appreciation of the need to use materials with as little embodied energy as possible. This includes energy used not only in extraction and manufacture but also the energy needed to transport materials to their point of use, a factor that favours the more local sourcing of materials. Issues of energy use over the life cycle of a building are also increasingly considered at the point of design including the fundamental questions of ‘what type of building will it be?’ and following on from that ‘what materials will it be made of?’ At the early design stage you may ask yourself questions like:

Will it be a heavyweight building with high levels of thermal mass that can • store free energy and shift temperature peaks, so lowering heating and cooling costs for a building? Will it be a lightweight structure with low embodied energy in which limited • amounts of mass are strategically located to store as much energy as possible in the floors or walls? How long do I want the building to stand and can we design the build-• ing so that the materials can be reused when the building is eventually demolished? How can we make sure that as little material waste is generated as possible • during construction and so reduce our materials costs by efficient design? How can we use materials that reduce our carbon footprint and even lock up • carbon within the fabric of the building? Will we carry out a full Life Cycle Assessment (LCA) of our building?•

Traditionally, builders would have known the answers to some of these questions automatically, being profoundly familiar with their own local materials. Today many designers do not ask such questions in an industry that is largely dominated by issues of first cost of materials. However, with the emerging emphasis on using ‘green’ materials there is a growing interest in using low-tech local materials that have a low impact over their entire life cycle, and it is these issues that are covered in this chapter, with reference to the use of one main material: lime.