ISO 14040 2006 “Environmental management — Life cycle assessment —Principles and framework” defines life cycle assessment (LCA) as a “compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle”
Life Cycle Assessment (LCA) is a tool for the systematic evaluation of the environmental impacts of a product or service system through all stages of its life cycle. LCA provides a method for environmental decision support.
LCA for buildings, assemblies or building products requires a thorough understanding of the way materials and products come together into assemblies and whole buildings that will then require operation and maintenance over their life and require deconstruction, reuse, recycling or disposal at the end of life. All of these phases contribute to the LCA of the building and must be considered in a way that preserves equivalence between any alternatives being evaluated.
The International Organisation for Standardisation (ISO), a world-wide federation of national standards bodies, has standardised this framework within the ISO 14040 series on LCA. ISO 14040:2006 “Environmental management — Life cycle assessment —Principles and framework”
The guidance on how best to use the BP LCI for all levels of assessment takes the form of a Protocol and it is a condition of use of the BP LCI data that the data be used in compliance with the Protocol.
LCA can be used for a very wide range of potential purposes including:
Specifically LCA provides a measure of all of the important environmental impacts of a building product from production to disposal or any intervening period selected by the goal and scope of the LCA. The life cycle of a product should include winning of raw materials through production, use, operation, cleaning and maintenance through to reuse, recycling or disposal (cradle to grave). For some purposes the goal and scope may be appropriately limited to one or more intervening phases of the life cycle (for instance cradle to building site or cradle to production gate). It is therefore important for any LCA to thoroughly define the goal and scope of the study.
A manufacturer of a product may choose to focus on the environmental impacts of production in order to innovate in product design or production processes because he has direct control over these phases in the life of his product. This approach will be instructive for the manufacturer but might be incomplete and misleading for the purchaser of the product – e.g. a low impact product may be demanding in maintenance or of limited lifespan.