Background Climate change threatens to undermine the past 50 years of gains in public health. In response, the National Health Service (NHS) in England has been working since 2008 to quantify and reduce its carbon footprint. This Article presents the latest update to its greenhouse gas accounting, identifying interventions for mitigation efforts and describing an approach applicable to other health systems across the world. Methods A hybrid model was used to quantify emissions within Scopes 1, 2, and 3 of the Greenhouse Gas Protocol, as well as patient and visitor travel emissions, from 1990 to 2019. This approach complements the broad coverage of top-down economic modelling with the high accuracy of bottom-up data wherever available. Available data were backcasted or forecasted to cover all years. To enable the identification of measures to reduce carbon emissions, results were disaggregated by organisation type. Findings In 2019, the health service's emissions totalled 25 megatonnes of carbon dioxide equivalent, a reduction of 26% since 1990, and a decrease of 64% in the emissions per inpatient finished admission episode. Of the 2019 footprint, 62% came from the supply chain, 24% from the direct delivery of care, 10% from staff commute and patient and visitor travel, and 4% from private health and care services commissioned by the NHS. Interpretation This work represents the longest and most comprehensive accounting of national health-care emissions globally, and underscores the importance of incorporating bottom-up data to improve the accuracy of top-down modelling and enabling detailed monitoring of progress as health systems act to reduce emissions. Funding Wellcome Trust.

The implications of the Probe post-occupancy survey project are discussed (methods and ndings have been discussed in papers 1 to 4). Recent pressures to improve the UK building industry and its products have so far focused on production and not performance in use. Feedback, however, reveals successes which are not immediately apparent even to experts (when newly completed, the best all-round performer in Probe did not make the shortlist for an environmental award), and that innovations can easily have unintended consequences. Meanwhile, persistent chronic low-level problems need to be tackled if we are to move towards the triple bottom line of more sustainable practice and create a base of sound practice upon which innovations can ourish. Factors for success include making sure essential features are in place; seeking simplicity, usability, manageability and responsiveness; identifying and managing downside risks; a culture of feedback with better benchmarking and constant review against client and design intentions; and more involvement of the supply side in improving and learning from the performance of buildings in use. Seven main themes are explored and initial actions suggested for the key industry players, clients and government.Keywords: benchmarks, brie ng, chronic problems, continuous improvement, design factors, factors for success, feedback, innovation, productivityDans cet article, les auteurs examinent les implications du projet Probe d'évaluation de la fonctionnalit é de bâtiments après emménagement (les méthodes et les résultats ont été examinés dans les articles 1 à 4). Récemment, les pressions exercées pour améliorer en Grande-Bretagne l'industrie du bâtiment et ses produits se sont, jusqu'à présent, concentrées sur la production et non sur le rendement en service. Toutefois, les informations reçues en retour révèlent des succès qui n'apparaissent pas immédiatement, même aux yeux des experts (à leur achèvement, les bâtiments ayant obtenu les meilleures notes dans le cadre du projet Probe n'ont pas été retenus pour une récompense au titre de la protection de l'environnement) et font apparaître que des innovations peuvent facilement avoir des conséquences inattendues. Pendant ce temps, il reste à résoudre de petits problèmes chroniques mais persistants si l'on souhaite aboutir au résultat essentiel qui consiste en des pratiques plus durables et à créer une plate-forme de pratiques saines à partir de laquelle les innovations pourront prospérer. Les facteurs de succès sont nombreux: il faut s'assurer que les caractéristiques essentielles sont en place, rechercher la simplicité, l'aptitude à l'usage, l'aptitude à la gestion et à la réactivité, recenser et gérer les risques en aval, ériger en culture le retour de l'information avec de meilleurs repères et se référer en permanence aux intentions des clients et des concepteurs, s'impliquer davantage du côté «approvisionnements » en améliorant et en tirant des enseignements des rendements de bâtiments en service. Les auteurs explorent sept grands thèmes ...

The call for action to transform the built environment and address the threats of climate change has been clearly made. However, to support the development, implementation and on-going evaluation of energy demand policy, a strong evidence base is needed to identify associations and establish underlying causes behind outcomes and variations in end-use energy demand within the population. A new approach to end-use energy demand research is presented which is founded on the interdisciplinary health sciences research framework of epidemiology, along with the establishment of a research centre. A case is made that through an 'energy epidemiology' approach a strong, population-level, empirically based research foundation can be advanced. Energy epidemiology is a whole-system approach that focuses on empirical research and provides a methodological framework for building physicists, engineers, sociologists and economists to engage in interdisciplinary work. The adaptation of the epidemiological approach to end-use energy demand studies will provide the means to observe and describe the trends and patterns of energy demand, to undertake and contextualize interventional studies, and to establish strong associations between factors that lead to an energy demand-related outcome or event. Such an approach would strengthen the evidence base to inform policy decisions and evaluate past intervention programmes or regulatory actions.Keywords: buildings, built environment, energy demand, epidemiology, evidence base, interdisciplinary, public policy, researchIl a été clairement lancé un appel pour mettre en place des mesures propres à transformer le cadre bâ ti et à faire face aux menaces du changement climatique. Néanmoins, pour soutenir l'élaboration, la mise en oeuvre et l'évaluation en continu de la politique relative à la demande énergétique, il est nécessaire de disposer d'une solide base de données factuelle pour identifier les associations et établir les causes sous-jacentes des résultats et des variations de la demande énergétique des utilisateurs finals au sein de la population. Il est présenté une nouvelle approche pour l'étude de la demande énergétique des utilisateurs finals, qui est fondée sur le cadre interdisciplinaire de l'épidémiologie utilisé pour les recherches dans les sciences de la santé, ainsi que sur l'établissement d'un centre de recherche. Il est fait valoir que, par une approche basée sur une « épidémiologie de l'énergie », il est possible de faire progresser la fondation d'une recherche empirique solide au niveau de la population. L'épidémiologie de l'énergie est une approche systémique globale qui est axée sur la recherche empirique et fournit un cadre méthodologique aux physiciens, ingénieurs, sociologues et économistes du bâ timent afin qu'ils participent à des travaux interdisciplinaires. L'adaptation de l'approche épidémiologique aux études relatives à la demande énergétique des utilisateurs finals donnera les moyens d'observer et de décrire les tendances et les schémas de la demande énergétique,...

11Energy simulation tools have a major role in the assessment of building energy retrofit (BER) 12 measures. Exergoeconomic analysis and optimisation is a common practice in sectors such 13 as the power generation and chemical processes, aiding engineers to obtain more energy-14 efficient and cost-effective energy systems designs. ExRET-Opt, a retrofit-oriented modular-15 based dynamic simulation framework has been developed by embedding a comprehensive 16 exergy/exergoeconomic calculation method into a typical open-source building energy 17 simulation tool (EnergyPlus). The aim of this paper is to show the decomposition of Opt by presenting modules, submodules and subroutines used for the framework's 19 development as well as verify the outputs with existing research data. In addition, the possibility 20 to perform multi-objective optimisation analysis based on genetic-algorithms combined with 21 multi-criteria decision making methods was included within the simulation framework. This 22 addition could potentiate BER design teams to perform quick exergy/exergoeconomic 23 optimisation, in order to find opportunities for thermodynamic improvements along the 24 building's active and passive energy systems. The enhanced simulation framework is tested 25 using a primary school building as a case study.