Assessment of building-integrated green technologies: A review and case study on applications of Multi-Criteria Decision Making (MCDM) method

Retrofitting existing buildings with appropriate green technologies is an important element of strategies to mitigate climate change. The selection of green technologies can be a challenging task, where multiple criteria exist and interrelate. However, it is still common for decisions to be based on a single criterion, such as energy efficiency or cost. This paper aims to evaluate the application of Multi-Criteria Decision Making (MCDM) methods to the selection of green technologies for retrofitting to existing buildings. The paper begins with a review of MCDM methods and the use of these techniques for selecting technologies to retrofit existing buildings. The applicability of Analytical Hierarchy Process (AHP), a widely used MCDM method, is demonstrated through a case study of a building that is part of a university estate. The findings show that AHP can help to formulate the problem, and facilitate the assessment and ranking of retrofitting measures when multiple criteria are jointly considered. We have shown that by considering environmental and economic criteria, control technologies such as variable speed drives in air handling units, rank most highly in this case. It has also been suggested that social criteria, such as occupant satisfaction, should also be considered as part of the sustainability agenda, although this can be more difficult to achieve than consideration of environmental and economic criteria, which are more readily characterised using quantitative data. We conclude by proposing an integrated green technology assessment and selection framework, which is applicable to existing buildings. (C) 2016 Elsevier Ltd. All rights reserved.