Rating Energy Sustainability of Urban Communities- A comparison of four sustainability assessment tools for urban areas

Abstract

With more than half of the world’s population now living in urban settlements, and the cities being bigger than ever imagined, sustainable urban development is one of the critical issues for the 21st century. The goal of sustainability has been embraced by many urban communities who have been committed to reducing their greenhouse gas emissions and the impact of their cities, districts, and neighbourhoods on the climate. Indisputably, one of the fundamental sustainability parameters that all urban communities wish to consider is energy sustainability. How can we assess the sustainability levels of an urban area though? And how can we monitor the transitional progress towards a clean energy future? A growing awareness of this necessity has recently led to the development of assessment tools for sustainable urban communities, one of the main features of which is to grade the energy sustainability levels achieved in urban areas. Owing to the fact that these tools have been launched recently, the number of scientific articles or studies analyzing them is limited. Therefore, in order to enhance the currently dearth of research in this field, this present study is focused on the analysis and comparison of four assessment tools for sustainable urban communities: BREEAM Communities, BREEAM Gebiedsontwikkeling, GPR Stedenbouw, and LEED for Neighbourhood Development. The main goal of the comparison was to examine how the four tools assess energy sustainability in the urban environment, to evaluate their strengths and weaknesses, and to draw up conclusions for an improved tool. To this end, the tools were, firstly, tested against theory and secondly, against a “real-world” case study area. For the theoretical comparison, an up to date literature review of current urban sustainability assessments led to the creation of a generic list of energy indicators for urban sustainable development. Based on this list, the tools were examined for the energy indicators they included and the compatibility they showed with the generic list. For the comparison against the “real-world” case study, the tools were applied in the Lijnbaan area, the central quarter of the city of Rotterdam, and conclusions were drawn in terms of their functionality. The results of the comparison of the tools with the generic list of energy indicators showed significant incompatibility. GPR Stedenbouw was the tool with the biggest overlap with the generic list; however, the tool still lacks several quantitative energy indicators measuring important themes of energy sustainability. Moreover, the comparison revealed that the tools focus on measuring the relative improvement of the energy performance of the urban area and its progress during time, but not the actual energy consumption of the area and the related CO₂ emissions. Consequently, an area that has achieved a high rating does not necessarily have lower energy consumption than an area with lower rating- such an oversight can lead to misleading results. Furthermore, the comparison showed that the methodology of most tools (except for BREEAM Gebiedsontwikkeling) gives more emphasis to certified buildings than to other themes of energy sustainability, such as energy efficiency of the area and renewable energy production. Therefore, the tools tend to consider urban areas as a sum of individual buildings, and thus, their methodologies overlook the important synergies that are necessary for designing sustainable urban areas. In addition, the application of the assessment tools in the Lijnbaan area revealed the complexity of the assessment process and the extensive amount of data that was required and often difficult to cover. In general, Lijnbaan scored very low in the energy themes of the tools, which can be explained by the fact that, within the studied period, there were no determined goals for improvement of the energy performance of this area. Besides, the prerequisite criteria for BREEAM and LEED certified buildings within the area, included in the respective tools, could not be fulfilled by Lijnbaan. As a result, the area failed to achieve any score, a fact that proves the limitations of the prerequisite criteria for certified buildings, which these tools included.