Terms and definitions on affordable and sustainable housing *

Post-occupancy Evaluation

Area: Design, planning and building

As the name suggests, Post-Occupancy Evaluation (POE) is the process of assessing the performance of a building once it has been occupied. It is often conflated and falls under the umbrella of Building Performance Evaluation (BPE) (Boissonneault & Peters, 2023; Preiser, 2005; Stevenson, 2018). Other definitions refer to POE as any activity intended to assess how buildings perform and the level of satisfaction of their users, ranging from simple survey questionnaires to indoor environmental quality (IEQ) measurements, which makes its scope very broad (Li et al., 2018). Nevertheless, in the case of POE, the focus should be on the occupants’ experience of the building and the impact of spaces on their behaviour and well-being (Watson, 2003 in Sanni-Anibire et al., 2016). It is commonly suggested that POE should be conducted at least a year after the handover and occupation of the building so that users can experience and test it under different weather conditions (RIBA et al., 2016). In the context of housing, housing providers, developers and architecture practices can benefit from enquiring what makes a good design from the occupants’ point of view. A systematic and rigorous POE combined with periodic user experience surveys can be very beneficial as it helps to improve relationships with tenants and provide a better picture of the quality of the housing stock. Thus, POEs do not only help to balance the scale between the social, economic and environmental aspects of buildings but also revitalise the role of research in the whole life cycle of projects. Despite its potential benefits for the various stakeholders engaged in the production of the built environment, POE is not a widespread practice in the sector. There is a notable absence of literature and research on the subject (Durosaiye et al., 2019; Hadjri & Crozier, 2009). However, since the 2010s, there has been a growing academic interest in POE, as evidenced by the increasing number of scientific publications, including studies related to post-occupancy evaluation (Li et al., 2018). There is a consensus in literature that learning from experience, whether from unintended consequences of ill-considered design or from successful projects, through the active involvement of occupants and users of buildings is a pathway for innovation. POE is commonly considered as an activity that requires long-term commitment and can be time and resource-consuming. This is a limitation that can be explained by the short-term logic of the construction sector and the fleeting commitment of developers, especially private and profit-driven, to the communities and clients they work with. In the same vein, the question of who is responsible for commissioning and conducting a POE represents the biggest barrier to its widespread implementation in the sector (Cooper, 2001). Concerns are inextricably linked to the cost and scope of the assessment, the equipment and professionals involved, and the possibility of being held accountable for flaws that might be exposed by the activity. Discussions around the importance of inspecting buildings after completion to assess their environmental performance have gained momentum in recent decades as a consequence of the evidenced climate crisis and the significant share of carbon emissions attributable to activities related to the built environment (according to UNEP (2022), 37 per cent of CO2 emissions in 2021). Nonetheless, the emergence of POE as a concept for the built environment dates back to the 1960s in the USA, where it was originally used to assess institutional facilities and fell mainly within the remit of facility managers (Preiser, 1995). Later, the PROBE (Post Occupancy Review of Building Engineering) research conducted between 1995 to 2002 on 23 non-residential case studies in the UK helped spread the concept among the whole gamut of professionals involved in the design and construction of buildings (Bordass et al., 2001; Cohen et al., 2001). With respect to design and housing, the work of Marcus and Sarkissian (1986) in Housing as if People Mattered is worth mentioning. In this book, the authors have outlined a set of design guidelines derived from evidence gathered through POEs. Their research was conducted with the aim of comprehending people's preferences and dislikes about their neighbourhoods and homes, utilizing a people-centred perspective that delves into " the quality of housing environments from a social standpoint, as defined by residents" (p.5). Their approach to POE is grounded in viewing housing as a process rather than a mere product. They propose rethinking the relationship between the designer and inhabitant, extending beyond the completion of buildings. This perspective aligns with that of Brand (1995), who views buildings as intricate systems governed by the 'Shearing layers of change', a concept developed from Duffy's proposal (Duffy & Hannay, 1992). Accordingly, buildings are understood as layered structures in which time plays a pivotal role in the way they interact with each other and with the user. As Duffy stated, quoted in Brand (1995, p.12): “The unit of analysis for us isn’t the building, it’s the use of the building through time. Time is the essence of the real design problem.” This renders it necessary to go back to the building once finished and continue doing so throughout its lifecycle. The levels of POE The literature distinguishes between three ‘levels of effort’ at which POE can be conducted, which differ mainly in terms of the thoroughness and purpose of the assessment: indicative, investigative, and diagnostic (Hadjri & Crozier, 2009; Preiser, 1995; Sanni-Anibire et al., 2016). These levels vary in methods and the degree of engagement of researchers and participants, and encompassing the phases of planning, conducting and applying. They can be described briefly as follows: Indicative: This level provides a general assessment of the most important positive and negative aspects of the building from the users' point of view. It involves a brief data collection period, characterised by walk-throughs, interviews and survey questionnaires with occupants. It is not exhaustive and may reveal more complex problems that need to be addressed with an investigative or diagnostic POE. It can be completed in a few hours or days. Investigative: If a relevant problem identified in an indicative POE requires further research, an investigative POE is carried out. This second level implies a more robust amount of data to be collected, the use of more specialised methods, and possibly the disruption of occupants' routines and building use due to the prolonged engagement in the research endeavour. It can take weeks to months to complete. Diagnostic: This level is characterised by its approach which is both longitudinal and cross-sectional. It may involve one or more buildings and a research process that may take months to a year or more to complete. It is more akin to research conducted by specialised institutions or scholars. The scope can be very specific but also have sector-wide implications. Possible applications of the information gathered through POE A more recent review of the literature on POE studies highlights the variegated range of purposes behind it: impact of indoor environmental quality on occupants, design and well-being, testing of technologies, informing future decision-making or feedforward, and impact of building standards and green rating systems, to name a few (Boissonneault & Peters, 2023; Li et al., 2018). The breadth of applications and rationale for conducting POE studies show that it is a powerful tool for assessing a wide array of issues in the built and living environment, and partly explain the interest it holds for researchers. However, the industry is still lagging behind, which hinders the dissemination and further implementation of the findings and results.  More collaboration between academia and industry is therefore crucial as the great impact lies in applying POE and BPE as a structural part of the sector’s practice. Moreover, since POE primarily relies on fieldwork and the collection of empirical data, a more comprehensive assessment that incorporates mixed methods and a systematic approach can yield greater benefits for the entire building production chain. The collected feedback, analysis and resulting conclusions can create learning loops within organisations and bring about real changes in the lives of current and future building users. Therefore, a robust POE should be accompanied by the implementation of the concomitant action plan to address the problems identified. For this purpose, a theory of change approach can be helpful. In this sense, POE can become a very effective facility management tool (Preiser, 1995). Some examples of the varied uses of data provided by robust POE and BPE include the creation of databases for informed decision-making, benchmarking and integration into BIM protocols or GIS-powered tools. In this sense, generating data that can be compared and benchmarked is critical to the long-term impact and value for money of undertaking the activity. It is therefore imperative to recognise POE for its benefits rather than viewing it as a liability or a mere nice-to-have feature. On the other hand, POE inherently involves a wide range of disciplines within the built environment, including design, engineering, psychology, policy and finance, among others. This multidisciplinary aspect can be leveraged to promote transdisciplinary research to help better understand the relationships between buildings and people It delves into the impact of these relationships, considering human behaviour and well-being. This perspective is often referred to as the building performance-people performance paradigm, as denominated by other POE researchers (Boissonneault & Peters, 2023). Architectural geographers, for instance, have explored the various meanings and emotions ascribed by inhabitants to buildings, particularly council estates in the UK, through actor-network theory-informed research (Jacobs et al., 2008, 2016; Lees, 2001; Lees & Baxter, 2011). Similarly, the work of organisations such as the Quality of Life Foundation encompassed in the Quality of Life Framework (Morgan & Salih, 2023; URBED, 2021), has highlighted the link between the places where we live and its impact on our quality of life through systematic POEs conducted in collaboration with social housing providers and local authorities. Amid the climate emergency and the pressing need to curtail carbon emissions, there is now a need for the sector to innovate and mitigate the impact of building construction and operation. It has been argued that sustainability cannot be achieved only by adopting energy-efficient technologies or by promoting certifications such as LEED, Passivhaus, or assessment protocols such as BREEAM (Building Research Establishment Environmental Assessment Methodology). As discussed earlier, conducting these assessments is an effective tool to mitigate and solve the discrepancy between the expected energy performance of the designed building vis à vis that of its real-life counterpart, the so-called performance gap. POE can be used to ascertain the social performance gap by including qualitative and well-being-related indicators (Brown, 2018). In this way, buildings are evaluated not only in terms of their ability to comply with building regulations and environmental goals, but also in meeting social objectives in order to provide greater sustainability and affordability, particularly in housing.

Created on 22-10-2023

Author: L.Ricaurte (ESR15)


* This vocabulary consists of definitions of key terms related to the combined research conducted by the 15 early-stage researchers. Each term has multiple definitions, each connected to one of the three main research areas: Design, Construction and Planning; Community Involvement; and Policy and Funding.

The joint construction of this vocabulary allows the researchers' projects to be interwoven. As such, the vocabulary is a tool for conducting transdisciplinary research on affordable and sustainable housing.

Entries are reviewed by RE-DWELL researchers and supervisors. The vocabulary is updated regularly.