The papers presented in this issue not only highlight neatly the complexities of trying to determine what could be considered ‘sustainable’ performance for a range of built assets but also demonstrate the broad sphere of influence in which engineers operate. Collectively, they provide a further, useful reminder of the potential contribution the engineering disciplines could and probably should make in delivering a sustainable future; a sentiment that has arisen previously in the journal and is likely, quite rightly, to recur in subsequent issues.
The start point provided in the first paper (Keirstead, 2014), however, takes us back to more fundamental issues. Namely, how do we educate our future engineers in such a way so as to ensure they are equipped with the essential skills of a rigorous discipline, but also help them understand the broader context within which the fruits of their labours will reside? In this regard the author's conceptualisation of sustainable development is useful, particularly the focus on ‘trying to anticipate how an initially attractive technical solution might be undermined by liabilities displaced beyond the original temporal or spatial boundaries of the analysis’. The nature of the potential manifold spatial and temporal liabilities or uncertainties is not only largely unpredictable but they are also generally beyond the control of engineers. Consequently, the development of a pedagogical framework that allows the implications of such uncertainties to be explored is likely to be extremely valuable. Keirstead's approach is centred on the development of a simple mathematical model based on a Cobb–Douglas production function. This is used to establish a familiar setting within which students can be introduced to the key principles of sustainable development. One of the compelling aspects of this approach is how the gradual development of the model provides opportunities for students to be prompted to engage in discussions; allowing them to be exposed to different definitions and disciplinary perspectives. This is essential if engineers are to be able to effectively make their contribution.
The second paper (Kinnane et al., 2014) introduces some of the most pressing issues facing the delivery of a sustainable built environment at an individual building scale; namely, the gap between design and in-use performance and the impacts associated with occupant perceptions and behaviour. Kinnane et al.'s paper is particularly apposite given the current focus on the potential adoption of building compliance based on as-built rather than as-designed performance. Consequently, frameworks that provide a systematic approach to understanding and resolving such issues will become increasingly important. While the aforementioned gap is a phenomenon that is much cited there is still a paucity of data regarding its precise nature. Kinnane et al.'s case study is very instructive and provides further evidence to support the assertions regarding what are thought to be the main causes. In particular, the in situ performance of the building envelope, the need to install systems appropriate to the profile of use of a space, and the effects of thermal mass on the operative temperature and hence on occupant comfort. The potential benefits of their user-centred approach clearly demonstrate why we have to grasp some of the more subjective and qualitative elements, such as user perceptions of comfort to ensure the buildings we deliver are fit for purpose over their whole life.
The third paper (Motevallian et al., 2014) provides further evidence for the need to adopt more inclusive assessment methodologies. In particular, those that explicitly include decision makers, systematically consider the more qualitative aspects of performance and can help understand the implications of uncertainty. Motevallian et al. establish a broader context at an urban scale and focus on specific infrastructure related to water systems although the lessons arising are likely to be as pertinent to the provision of other utilities at an urban scale. Their analysis captures some of the complexities inherent in trying to deliver such inclusive assessment methodologies. Perhaps chief amongst these is the difficulty in capturing the sophistication of interactions between the system under study and the users. User responses to a range of technological interventions or policy instruments will ultimately determine the relative sustainability of any given option over its whole life time, yet it is these relationships that are perhaps the most uncertain and therefore the most difficult to capture. Clearly, we can postulate likely outcomes but the need to effectively integrate some kind of dynamic analysis and test the implications associated with a range of responses is very well made.
The final paper (Pritchard et al., 2014) seeks to address this issue specifically for the implications of climate change on soil conditions and the subsequent impact on utility infrastructure. Pritchard et al.'s paper encapsulates many of the themes that have emerged in the preceding papers. In particular, the problems inherent in trying to assess systematically the implications of something that is inherently qualitative and understand the risks associated with different levels of uncertainty. Variations in soil conditions arising from climate change pose significant threats to the long-term efficacy of utility infrastructure, both new and existing. Ultimately dealing with these threats calls for decision makers from a range of disciplinary backgrounds to work collaboratively and ensure both expert and practitioner knowledge can be harnessed effectively. Only in this way can we understand the impacts of different levels of risk and deliver truly sustainable infrastructure.
The three case studies in this issue highlight a very clear need for stakeholders involved in delivering a sustainable built environment to be able to work effectively across disciplinary boundaries; whether this is engaging with different occupant or user groups, policymakers or experts in the analysis of risk and uncertainty. A fundamental skill for engineers involved in such activities will be the ability to understand the language and perceptions of a range of disparate disciplines and know how to quantify some of the implications of the uncertainties they face. Such a need makes the implementation of approaches such as that outlined by Keirstead (2014) in the first paper all the more imperative.
The issue is completed by a book review of Sustainable Retrofitting of Commercial Buildings: Warm Climates (Aristizabal–Ochoa, 2014).
