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MPhil in Engineering for Sustainable Development

global challenges, engineering solutions

New tools for improving user feedback loops in building retrofit and maintenance


Costly energy-efficient retrofits frequently fail to deliver on projected energy savings (Bordass et al. 2004). All too often, the problem is that the building’s complex operational system clashes with the behaviour of its occupants (Menezes et al. 2012). Designers, manufacturers, and policy makers lack insights on how novel measures aimed to increase energy savings really perform for the user, and how they impact specific user behaviours. Consequently, shortcomings are detected late, and the learning curve for sustainable innovations remains flat. It is thus crucial to investigate the relationship between buildings and their users’ preferences (Steemers & Yun 2009), and to establish swift and precise occupant feedback mechanisms.

This research therefore set out to explore web-based and social media techniques to strengthen occupant feedback loops. Through an exploratory case study in the Cambridge University Engineering Department, it tested Facebook and short online surveys as tools to collect occupants’ time-referenced, momentary emotions associated with the indoor environment. The study additionally investigated the usefulness of the gathered data in conjunction with temperature and weather logs. Three groups side by side provided user feedback: Group 1 completed the established, paper-based Building Use Studies (BUS) Survey. Group 2 answered a series of short online surveys, which the participants received daily by email. Group 3 used a Closed Facebook Group, in which members were encouraged to complete the same short online surveys as Group 2, and actively post their views on the building, as well as ‘like’ and comment on other posts. At the end of the study, members of Group 2 and 3 were asked to complete the paper-based BUS-Survey as well; this allowed comparing the different methods on identical participants.

The case study revealed significant challenges for using social media for occupant feedback. The Closed Facebook Group was unpopular, ultimately only 15 occupants joined the group and their participation was low. Only one occupant opted for a potential fourth Twitter group; thus this method was not pursued. Conversely, the email-based group using the longitudinal short online survey method achieved a much higher participation rate; over the course of four weeks 15 surveys collected 443 survey responses. Temporal and spatial overlay techniques were tested to combine the occupant feedback with other building data on a time line as well as on a floor plan. This contributed to more fine-grained and context-sensitive information, enabling a better understanding of patterns and interdependencies. As a result, air-conditioning was identified as a major issue in the building.

In conclusion, this research adds evidence to the importance of integrating the ‘human element’ in the current, technology-driven energy-efficiency efforts. The case study itself showcased that exploring new tools for occupant feedback represents not a mere technical, but a complex, socio-technical challenge. Further research should advance and validate the short online survey method as an add-on to existing one-off occupant feedback methods. Branching techniques should be tested in order to focus in-depth investigations exclusively on problematic areas. Prior to a more widespread use, however, processes have to be explored that allow for a greater anonymity and strictly control the access to sensitive information.

Course Overview


The need to engage in better problem definition through careful dialogue with all stakeholder groups and a proper recognition of context.


An ability to work with specialists from other disciplines and professional groups acknowledging that technical innovation and business skills also must be understood, nurtured and combined as precursors to the successful implementation of sustainable solutions.


An understanding of mechanisms for managing change in organisations so future engineers are equipped to play a leadership role.


An awareness of a range of assessment frameworks, sustainability metrics and methodologies such as Life Cycle Analysis, Systems Dynamics, Multi-Criteria Decision making and Impact Assessment.