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

- 78 -The Green Star NZ office design v 1.2 tool was developed for the design stage of officebuildings to evaluate the environmental initiatives and/or potential environmental impacts ofcommercial office base building designs.In Green Star, credits are awarded for certain activities. For example 1 point is awarded whereit can be demonstrated that the percentage of all steel in the design has a post-consumerrecycled content great than 60 % by mass, and 2 points for 90 % by mass. If the material costof steel represents less than 1 % of the project’s total contract value then this credit would be“not applicable”. Similarly 2 points are awarded where it is demonstrated that all timber andcomposite timber products are either post-consumer re-used timber or FSC certified timber ora combination thereof. In other categories points are awarded for land use, IEQ, transport etc(Figure 6.18).Figure 6.18: Green Star methodology (NZGBC 2008)All points are then weighted and summarised into a single score, where materials have acontribution of 10 % to the total score whereas energy has a contribution of 25 %. For allweightings see Table 6.12.Table 6.12: Weightings in Green Star toolManagement 10 %Indoor Environmental Quality 20 %Energy 25 %Transport 10 %Water 10 %Materials 10 %Land Use and Ecology 10 %Emissions 5 %100 %6.4.3 Research Approach for ComparisonDue to the differences in the scope of both tools, the comparison was restricted to thoseaspects which are taken into account in both tools, i.e. material use and energy use. Allfeatures of the buildings that are not strictly material or energy use related were therefore