Criteria weighting for green technology selection as part of retrofit decision making process for existing non-domestic buildings

The implementation of green technologies, as part of retrofit, can significantly improve building performance. However, green technology selection is a complex decision making process due to multiple evaluation criteria and often conflicting interests of different stakeholders involved. This paper proposes default criteria weights based for previously-developed criteria tree consisting of in total 39 criteria organised around environmental, economic, social and technical performance of green technologies. Web-based surveys of experts including architects, engineers, planners in the UK and China were conducted to capture expert opinions on sustainability and technical criteria. Analytical Hierarchy Process (AHP) method was used to calculate default criteria weights. Comparisons between expert groups in different countries were also performed. Results show that UK experts more concern about Economic performance of green technology, specifically with UK architects and engineers assigning high weights on Cost. For the Environmental category, Reduction of energy consumption and Reduction of water consumption are ranked as the most important topics under In-use environmental performance by all experts. UK experts have shown a growing concern on Reduction of water consumption. Under The improvement of indoor environmental quality, Thermal comfort is ranked as the most important criterion by UK experts and Visual comfort is weighted as the first priority by Chinese experts. Compared with UK experts, Chinese experts have placed a significant importance on Technical criteria, represented by engineer group emphasising on Durability for this category.