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

- 56 -The life cycle inventory data used in this study is from two key sources:The data for most building materials is based on a new dataset that has been developed as partof the project “Life Cycle Assessment: Adopting and adapting overseas LCA data andmethodologies for building materials in New Zealand” by Nebel et al. (2009). In this projectEuropean-based industry data was combined with New Zealand specific data, compiled andcalculated by Alcorn (1995, 1998, 2003) at the Centre for Building Performance Research atVictoria University.Data for materials that are not included in this dataset are based on data that is part of a LCAsoftware package (GaBi 4.3) and is based on European industry data. The data has beenamended and checked for consistency with literature data (GaBi 2006) and is compliant withthe ISO Standards 14040 and 14044. The documentation of the data describes the productionprocess, applied boundary conditions, allocation rules etc. for each product. The data coversresource extraction, transport, and processing, i.e., “cradle to gate”. Included are materialinputs, energy inputs, transport, outputs and as well as the emissions related to energy use andproduction. Capital equipment is excluded 3 .A New Zealand specific dataset for the provision of electricity is provided in the GaBidatabase, based on the average GridMix of 2004.6.3.2.4 Intended Audience and Application of the ResultsThe study was undertaken for the Ministry for Agriculture and Forestry. It is anticipated thatthe results will be used to inform policy making. The results can also be used to demonstratethe benefits of a life cycle approach when comparing different building designs.6.3.2.5 Impact Assessment MethodologiesPrimary energy, as an indicator for resource consumption, and Greenhouse gas emissions(global warming potential), as one of the most important environmental impacts, have beenconsidered.6.3.2.6 Primary EnergyPrimary energy is energy contained in raw fuels and any other forms of energy that has notbeen subjected to any conversion or transformation process. Primary energies are transformedin energy conversion processes to more convenient forms of energy, such as electrical energyand cleaner fuels. The transformation includes losses that occur in the generation,transmission, and distribution of energy. For example, the provision of 1 MJ of electricityfrom natural gas requires 2.6 MJ of primary energy (GaBi 4.3). Primary energy consumptionfor “cradle to gate” or “cradle to site” is often referred to as “embodied energy”.Embodied energy is the energy consumed by all processes from extraction of raw materialsthrough to the production of a product. The definition of the system boundaries vary fordifferent assessments and sometimes include the delivery to the building site, energyrequirements for installation, and transport of workers to the site (“cradle to site”). However,data for these processes is often hard to quantify. Published figures for embodied energy aretherefore often based on a “cradle to gate” concept.3 Capital equipment does not need to be included in LCA studies of construction materials (Frischknecht et al.2007).