Design consequences of differences in building assessment tools: A case study

Environmental assessment tools for buildings are emerging rapidly in many countries. Do different assessment tools influence the design process and also guide 'green' building projects in different directions? Three assessment tools, Leadership in Energy and Environmental Design for New Construction (LEED-NC), Code for Sustainable Homes (CSH) and EcoEffect, were tested in a case study project in Sweden: a new multi-storey residential building called Gronskar. The content and results of the three assessment tools were compared in general, while issues in the three core common categories of Energy, Indoor Environment and Materials Waste were compared in more detail. The assessment results for the case study building varied with the three tools, and the design strategies and tactics to improve the overall rating of the building project differed for each tool. This confirms that the tools can influence sustainable building in different directions and illustrates insufficient consensus between assessment tools in terms of issues, criteria and weighting. The divergent results highlight the need for an appropriate structure of assessment tools that are both environmentally relevant and practically useful.