Environmental Impacts of Multi-Storey Buildings Using Different ...

- 51 -6 Life Cycle Assessment6.1 IntroductionThis section of the report investigates some of the environmental impacts of the fouralternative building designs through the use of Life Cycle Assessment (LCA).This work was carried out by Scion, a New Zealand Government Crown Research Institute(CRI).6.2 BackgroundLife Cycle Assessment (LCA) is the central theme of this research project. However, the LCAstudy is dependent on research and results obtained from other parts of the overall project,undertaken prior to the LCA. The necessary steps before being able to undertake the LCAstudy are summarised below;1. The design of four buildings – Concrete, Steel, Timber and TimberPlus.2. The quantification of the construction materials used in each building.3. Operational energy modelling and results for each design.Building on the above research, the LCA study compares the lifetime primary energyconsumption and the global warming potential (GWP) of the four buildings and investigatesthe environmental hotspots of each building.6.2.1 LCA OverviewLife Cycle Assessment is based on the concept of Life Cycle Thinking which integratesconsumption and production strategies over a whole life cycle, so preventing a piece-mealapproach to systems analysis. Life cycle approaches avoid problem-shifting from one lifecycle stage to another, from one geographic area to another, and from one environmentalmedium to another.Life Cycle Assessment is an analytical tool for the systematic evaluation of the environmentalimpacts of a product or service system through all stages of its life. It extends from extractionand processing of raw materials through to manufacture, delivery, use, and finally on to wastemanagement. This is often referred to as “cradle to grave”. A number of other environmentalassessment tools are restricted to the production process, which is sometimes called “gate togate”, or in the case of embodied energy covers the life cycle from “cradle to gate” withouttaking the end-of-life into account.6.2.2 Definition of LCAISO 14040 defines LCA as:“… a technique for assessing the environmental aspects and potential impacts associatedwith a product, by• compiling an inventory of relevant inputs and outputs of a product system;