Towards measurement and verification of energy performance under the framework of the European directive for energy performance of buildings

Directive 2002/91/EC of the European Parliament and Council on the Energy Performance of Buildings has led to major developments in energy policies followed by the EU Member States. The national energy performance targets for the built environment are mostly rooted in the Building Regulations that are shaped by this Directive. Article 3 of this Directive requires a methodology to calculate energy performance of buildings under standardised operating conditions. Overwhelming evidence suggests that actual energy performance is often significantly higher than this standardised and theoretical performance. The risk is national energy saving targets may not be achieved in practice. The UK evidence for the education and office sectors is presented in this paper. A measurement and verification plan is proposed to compare actual energy performance of a building with its theoretical performance using calibrated thermal modelling. Consequently, the intended vs. actual energy performance can be established under identical operating conditions. This can help identify the shortcomings of construction process and building procurement. Once energy performance gap is determined with reasonable accuracy and root causes identified, effective measures could be adopted to remedy or offset this gap

Building Schools for the Future: Lessons Learned From Performance Evaluations of Five Secondary Schools and Academies in England

Building performance evaluations (BPE) of five secondary schools and academies constructed under the Building Schools for the Future (BSF) programme in England found that CO2 emissions associated with operational energy performance in all these buildings is higher than the median of the secondary schools. Whilst the new regulatory requirements for building fabric performance have led to some improvements in heating energy when compared against good practice and typical benchmarks, there is still significant discrepancy between heating energy use and the design expectations. Electricity use in these buildings is also 37–191% more than the median school and significantly worse than the design expectations. These results point to the importance of post-occupancy building fine-tuning and measurement and verification of performance in-use with respect to design projections to narrow the performance gap. It is also necessary to set out clear operational performance targets and protect energy efficiency measures from value engineering throughout building procurement and in operation to achieve good level of performance. Finally, it is suggested to adopt a holistic view of energy, environmental quality, and educational performance to have a better understanding of schools' performance and potential conflicts between energy efficiency measures and indoor environmental quality (IEQ)

Energy use predictions with machine learning during architectural concept design

Studies have shown that the actual energy consumption of buildings once built and in operation is often far greater than the energy consumption predictions made during design—leading to the term “performance gap.” An alternative to traditional, building physics based, prediction methods is an approach based on real-world data, where behavior is learned through observations. Display energy certificates are a source of observed building “behavior” in the United Kingdom, and machine learning, a subset of artificial intelligence, can predict global behavior in complex systems, such as buildings. In view of this, artificial neural networks, a machine learning technique, were trained to predict annual thermal (gas) and electrical energy use of building designs, based on a range of collected design and briefing parameters. As a demonstrative case, the research focused on school design in England. Mean absolute percentage errors of 22.9% and 22.5% for annual thermal and electrical energy use predictions, respectively, were achieved. This is an improvement of 9.1% for the prediction of annual thermal energy use and 24.5% for the prediction of annual electrical energy use when compared to sources evidencing the current performance gap

Reconciling Resilience and Sustainability in Overheating and Energy Performance Assessments of Non-domestic Buildings

Sustainability and resilience are generally acclaimed as favourable attributes of techno-socio-economic systems. However, they often encompass system characteristics that are not necessarily consistent. A manifestation of the concept of resilience in the built environment is overheating resilience, which is ever increasingly important given the rise in average global temperatures. A key sustainability objective, on the other hand, is building energy performance. In this paper, overheating risk and energy performance of non-domestic buildings are reviewed in the context of resilience and sustainability frameworks. Subsequently, different engineering approaches adopted to reconcile overheating resilience and energy sustainability along with their environmental outcomes are reviewed using the evidence gathered from two educational buildings in London. The results of this investigation along with other evidence available for nondomestic buildings have been used to develop a risk assessment framework that could help in achieving thermally resilient and energy efficient buildings

A comparative study of the energy certification schemes implemented in the UK and ASHRAE building energy labelling programme

Following inception of the Energy Performance of Buildings Directive (EPBD) in the EU, energy certification schemes have gained prominence in the UK in recent years. Introduction of building Energy Quotient (bEQ), ASHRAE’s new building energy labelling programme, provides an opportunity to compare these schemes and explore improvement opportunities. ASHRAE’s bEQ broadly follows the same principles that underpin the energy certification schemes implemented in the UK. However, greater consistency in baselines defined for the ‘As Designed’ and ‘In Operation’ schemes, attention to key determinants of energy use based on building type, and an integrated approach to operational rating & indoor environmental quality are among the key contributions of bEQ that can help improve building energy certification programmes

Dal progetto alla gestione: un processo di benchmarking per l’efficienza energetica degli edifici - From design to management: a benchmarking process for the energy efficiency of buildings.

La qualità ambientale e l’efficienza energetica sono obiettivi strategici che possono far luce sulla ‘bontà’ di scelte progettuali e tecnologiche, sull’impatto della gestione di un edificio e del comportamento degli utenti, ma che anche incidere sullo sviluppo del settore edilizio. Molte ricerche sul comportamento energetico degli edifici hanno prodotto innumerevoli costruzioni teoriche, perché basate su un ridotto numero di dati raccolti scientificamente. Alcuni paesi europei sono, invece, impegnati da anni in attività di monitoraggio e valutazione della loro produzione edilizia, attraverso una raccolta sistematica di dati sugli edifici in fase di esercizio. Ricerche recenti dimostrano, infatti, che il gap tra consumi energetici attesi e in uso può essere ridotto se si considerano in modo integrato le prestazioni tecniche, il comportamento degli occupanti e i sistemi di gestione, specialmente negli edifici pubblici. Nel contesto italiano, occorre tuttavia osservare che non sono diffuse procedure di Monitoraggio e Valutazione o di Valutazione post abitativa, tanto meno di benchmarking per poter comparare le reali prestazioni tecniche degli edifici. Per poter andare oltre la valutazione delle prestazioni energetiche degli edifici, mettendo progettisti, proprietari, gestori e investitori in condizione di elaborare scelte informate, basate su prove di efficacia (Evidence Based Design), occorrono strumenti e protocolli per un migliore e rapido feedback. Nel Regno Unito, un consorzio di industrie e università ha realizzato la piattaforma ‘Carbon Buzz’ per mettere a confronto le prestazioni energetiche ‘progettate’ con quelle realmente raggiunte. A seguito dell’esperienza britannica, ricercatori dell’Università Roma Tre e dell’UCL-University College of London e di Aedas R&D, appartenenti al gruppo che ha elaborato Carbon Buzz, ha sviluppato, a sua volta, una piattaforma italiana che, attraverso dati strutturati e confronti, aiuta a mettere in relazione scelte progettuali, tecnologiche e di gestione con le prestazioni energetiche e le emissioni di Co2. A partire dallo stato dell’arte delle ricerche sulla valutazione delle prestazioni energetiche, questo articolo pone l’attenzione sullo sviluppo dei protocolli decisionali basati sull’Evidence-Based Design (EBD), presenta la piattaforma e la metodologia seguita per definirla in rapporto al quadro legislativo italiano e alle caratteristiche del modus costruendi italiano, ne illustra potenzialità, limiti e possibili sviluppi, attraverso l’applicazione su alcuni casi studi di edifici universitari.Today monitoring the actual energy consumption and performance of buildings is a main topic for defining their environmental quality, since it can also shed light on the effective ‘goodness’ of technological and design solutions tailored to this aim and on the impact management strategies and users’ behaviours have. Recent researches demonstrate that the gap between designed and expected energy consumptions requires new approaches integrating technical performances, occupant behaviour and energy management systems, especially in public buildings. To this aim it seems that in Italy there are no suitable Monitoring&Evaluation and Post Occupancy Evaluation, or benchmarking procedure to compare performances. To go beyond the headline assessment of energy performance of buildings and to provide evidence based design advice to various stakeholders (designers, owners, managers and investors) on how their buildings are performing, we need better and rapid feedback tools/protocols. In the UK, a consortium of researchers from industry and academia has created an online evidence based design platform called Carbon Buzz. Following this experience, researchers from Roma Tre University have formed a group with UCL and Aedas R&D to create an innovative Italian platform and experiment its application to some buildings of Roma Tre University, with the aim to provide advice on how choices related to design, construction and management of a building could affect its carbon emission

Sustainably Tall: Investment, Energy, Life Cycle

The purpose of this project is to provide an interactive platform for clients and design teams to evaluate the consequences of shape, form, and briefing decisions on the energy use, embodied energy, and capital / life-cycle cost of a tall building early in the design process. The Tall Building Simulation (TBS) model is the result of a collaborative partnership between Aedas, Arup, Hilson Moran (HM), and Davis Langdon (DL). It is estimated that most decisions determining the sustainability of a project are made in the first 1 percent of a projectis program, whereas the majority of the information required for sustainability  assessment is not usually available or examined until after the concept stage. By this time, most solutions would need design or briefing changes that are too costly to implement. Using the TBS model, architects, engineers, and clients can simultaneously explore the impact of typical technical and design decisions on a tall buildingis energy footprint and its dynamic relationship to cost at the briefing stage.

Users' behaviours, management and technical solutions: A fundamental integration for low carbon buildings. The case of Roma Tre university

"Introduction. Considering that buildings are responsible for more than 40% of energy consumption, energy situation is critical and European legislative framework is more and more restrictive, a good way to reconcile economy logics with sustainability ones seems to be the “bearable” management of the existing building estate. This is possible by monitoring building performances and energy consumptions, and by evaluating management strategies and users’ behaviours. This paper presents a web platform apt to operate such procedures. This tool started from the English CarbonBuzz, elaborated by Aedas and University College of London, and evolved into a new version apt to meet the Italian situation and detect “proofs” of the actual effectiveness of design solutions.. Theoretical background. The environmental degradation and life quality low standards signal that the well-balanced relation between building and dwelling is jeopardized. If dwelling represents the aim (according to Heidegger, literally the way men live), building is the artificial action men take to transform natural environment in relation to life demands (Losasso, 2005). The actions men take to shape their habitat are ruled and steered by technological processes that, processing matter, energy and information give back products and “organisms” in which incoming and outgoing matter and energy flows act. A new operational approach considers that reliable data are combined with the attention paid to the evaluations given by users (Gupta e Chandiwala, 2010). The study of users’ perceptions and behaviours supplies designers, and then producers, with meaningful feedback that enable them to detect solutions meeting users’ requirements better and reducing the gap between expected and actual building performances. The users’ participation to the process takes them to build a stronger link with the premises, a sense of belonging and consequently to feel responsible and keep congruent behaviours (Risser et al., 2006). Italy, compared to other countries such as the UK, lacks a suitable benchmarking, aimed at monitoring comparative performances, and Post Occupancy Evaluation protocols, apt to evaluate building performances after a time from their occupancy. The real transition to a green building economy can become effective only overcoming the mere sustainable design (a necessary but not sufficient condition) and aiming for a sustainable dwelling (Dall’O’, 2011).. Methods. Starting from the English platform, the Italian version modified and implemented some aspects that were different. Though they both respected the general principles in accordance with European directives, some peculiarities regarding: national rules, climatic and geographic conditions, building and equipment systems, management and way of living buildings took to elaborate specific parameters for the design and in use phase (towards a specific year of reference). A methodology for collecting the data was devised and applied to some buildings of Roma Tre University, in order to test the first version of the platform. A technical classification, based on some building aspects and on the energy certifications at design stage, was made. These data were confronted with effective energy consumptions bills, surveys and enquiries involving managers and users.. Results . An early database of the case studies was created; morphology, technology, system and management variety allowed to carry out a double control: on the one hand to compare parameters of consumption with CO2 emissions in a sample of buildings with the same end use; on the other hand to compare design and in use data, concerning the monitoring of effective bills for the single building. By these analyses, in a more in depth phase, it is possible to distinguish the energy end uses and to understand where and how to take action in order to improve buildings efficiency, as well as to involve actively users by crowd sourcing procedures, complementary to other interview methods. . Conclusions. The research enables both teams, English and Italian, to draw conclusions regarding the methodology to detect energy consumptions systematically, the implementation of environmental mitigation measures, the consideration of needs and behaviours of users, just for their being at the core of the design and evaluation process. . Reference. Gupta R. e Chandiwala S., Understanding occupants: feedback techniques for large-scale low carbon domestic refurbishments, in “Building Research & Information”, 38:5, 530-548,2010. Losasso M., “La dimensione sostenibile nel progetto architettonico”, in M.Losasso, a cura di, Progetto e innovazione, CLEAN 2005,p.30. Risser R., Schmeidler K., Steg L., Forward S., Martincigh L., Assessment of the quality of life in cities. Environmental conditions and mobility, in: Urbani Izziv, vol. 17,No. 1-2\/06,The forgotten modernism of cities. .

Users’ behaviours, management and technical solutions: a fundamental integration for low carbon buildings. The case of Roma Tre University

Considering that buildings are responsible for more than 40% of energy consumption, that the energy situation is critical and European legislation is more and more restrictive, a good way to reconcile economy and sustainability logics seems to be the “bearable” management of existing buildings. This is possible by monitoring building performances and energy consumption and by evaluating management strategies and users’ behaviours. For performing such procedures, a web platform was developed by Aedas and UCL: Carbon Buzz. Within the research project: “From design to management: a benchmarking process for the energy efficiency of buildings”, carried out by Roma Tre University together with UCL and AEDAS, a new version of the British platform was designed in order to meet the Italian situation and detect “proofs” of the actual effectiveness of design solutions. An early database of case studies made it possible to carry out a double investigation: on the one hand to compare building parameters with consumptions/CO2 emissions in a sample of buildings with the same end use, and on the other, to compare design and in-use data for single buildings. In this paper, this first part of the research is dealt with briefly, having been widely described also in other papers, while the following part, that represents a further deepening of the international project, is dealt with more exhaustively, analysing results that had never been published before. The comparison between the levels of performance predicted during the design stage and those measured at the “in-use” stage, showed a gap that seems mainly due to unregulated energy uses. The work then focused on protocols of Post Occupancy Evaluation (POE) and occupancy data (times, spaces and ways of use). An enquiry was made in one of the university buildings, as a pre-test of the methodology, and tools were devised for the contextual survey and analysis of objective aspects (building performances and management) and subjective aspects (users’ opinions and behaviours) concerning comfort levels. Using specific procedures, such as the comparison to thresholds of both the actual performances offered by the analysed spaces and the percentages of users expressing different levels of satisfaction and importance for each enquiry field, the collected data were processed and assessed. On the basis of these first results, by turning precise values into similar synthetic ranges of values, representing quality and appraisal levels, it was possible to make a comparison between subjective and objective evaluations of some wellbeing conditions. The aim was to understand, on the one hand, how much occupants affect unregulated loads, on the other, how they perceive their indoor environment. Therefore, causes of dissatisfaction for the wellbeing conditions in the heating period, and consequent symptoms of ailment, were also detected. The applied methodology enables one to address the issues that are most urgent and relevant for users, to identify which aspects need to be improved, both from architectural (technical solutions, components and systems) and operational (ways of use and management) viewpoints, and finally which are the priorities for action. Further steps in the research, as better explained in the paper, are already planned.Considering that buildings are responsible for more than 40% of energy consumption and that the energy situation is critical and European legislation is more and more restrictive, a good way to reconcile economy and sustainability logics seems to be the “bearable” management of existing buildings. This is possible by monitoring building performances and energy consumption and by evaluating management strategies and users’ behaviours. This paper presents a web platform for performing such procedures. Based on the British platform Carbon Buzz, developed by Aedas and UCL, a new version was designed to meet the Italian situation and detect “proofs” of the actual effectiveness of design solutions. An early database of case studies enabled us to carry out a double investigation: on the one hand we compared building parameters with consumptions/CO2 emissions in a sample of buildings with the same end use, and on the other, we compared design and in-use data for single buildings. An enquiry was made in one of the buildings as a pre-test of the tools devised for surveying and observing both technical and management aspects and users’ opinions and behaviours. Using a specific procedure, the collected data were processed and assessed. On the basis of these first results, a comparison was made between subjective and objective evaluations of some wellbeing conditions. Moreover, causes of dissatisfaction and consequent symptoms of ailment were detected