Environmental assessment of the urban environment

Abstract: This thesis gives a systematic description of theEnvironmental Load Profile (ELP), an environmental assessmenttool developed for the urban environment. The purpose of thework was to improve the stringency of the system boundaries andfunctional units of the tool. This was achieved by putting theELP structure in the context of Life Cycle Assessment (LCA)with a special emphasis on system boundaries. To create animproved scientific base for the ELP, a comparative study wasconducted using an evaluative framework for conceptual andanalytical approaches. Here, the ELP tool is compared with foursimilar environmental assessment tools for the builtenvironment.Since, energy use in the operation phase is an importantfactor for the overall environmental performance of buildings,a sensitivity analysis was performed to investigate how theselection of heat and electricity mix affects the results of anenvironmental assessment of buildings. Four modes ofelectricity production and two modes of heat production wereapplied on three buildings with different technical systems intheir heat supply. The results show that the choice ofelectricity mix has a great influence on the outcome of anenvironmental assessment (EA) and it is suggested that both anaverage and marginal electricity mix should be applied inEA´s of the built environment. Further, it is argued thatconsequences of assumptions made should be explicitlycommunicated in the EA report, to allow the decision-makersrather than the analysts to make the final evaluation.The ELP is primarily developed to follow up theenvironmental goal‘twice as good’and assess theenvironmental performance of Hammarby Sjöstad, a newcity-district in southern Stockholm. The city-district is builtas a continuation of the inner Stockholm and the first part ofthe project, called Sickla Udde, is nearly finished. The ELPtool was applied in a first case study to answer the questionof how far Sickla Udde has reached in achieving the goal. Theassessment indicates that compared to a reference districtbased on the technology used in 1990, the environmentalperformance of Sickla Udde has reached the goal‘twice asgood’for some environmental load categories and 30percent for others. Although these findings are preliminary,they indicate a development in the right direction. Measurestaken contributing to largest environmental improvements are: amore efficient energy production (improved district heating)and use (e.g. lower U-values in the buildings, energy efficientappliances, heat exchange of ventilation air) and improvedsewage treatment. The results also demonstrate that theenvironmental load from domestic transports can be of the samemagnitude as from the buildings situated within thecity-district. Hence, resources spent to decrease environmentalload in the planning process should primarily be divoted toimproving domestic transportation systems and on optimising theoperational phase of the buildings.Keywords:environmental assessment, urban district,environmental load profile, Hammarby Sjöstad, life cycleassessment, LCA, environmental management, builtenvironment