Integrating Smart Ceiling Fans and Communicating Thermostats to Provide Energy-Efficient Comfort

The project goal was to identify and test the integration of smart ceiling fans and communicating thermostats. These highly efficient ceiling fans use as much power as an LED light bulb and have onboard temperature and occupancy sensors for automatic operationbased on space conditions. The Center for the Environment (CBE) at UC Berkeley led the research team including TRC, Association for Energy Affordability (AEA), and Big Ass Fans (BAF). The research team conducted laboratory tests, installed99 ceiling fans and 12 thermostats in four affordable multifamily housing sites in California’s Central Valley, interviewed stakeholders to develop a case study, developed an online design tool and design guide, outlined codes and standards outreach, and published several papers.The project team raised indoor cooling temperature setpoints and used ceiling fans as the first stage of cooling; this sequencing of ceiling fans and air conditioningreducesenergy consumption, especially during peak periods, while providing thermal comfort.The field demonstration resulted in 39% measured compressor energy savings during the April–October cooling seasoncompared to baseline conditions, normalized for floor area. Weather-normalized energy use varied from a 36% increase to 71% savings, withmedian savings of 15%.This variability reflects the diversity in buildings, mechanical systems, prior operation settings, space types, andoccupants’ schedules,preferences, and motivations. All commercial spaces with regular occupancy schedules (and twoof the irregularly-occupied commercial spaces and one of the homes) showed energy savings on an absolute basis before normalizing for warmer intervention temperatures,and 10 of 13 sites showed energy savings on a weather-normalized basis. The ceiling fans provided cooling for one site for months during hot weather when the coolingequipment failed.Occupants reported high satisfaction with the ceiling fans and improved thermal comfort. This technology can apply to new and retrofit residential and commercial buildings

Energy-Efficient Office Renovation:

This research aims to develop user-focused design principles for energy-efficient office renovations. The goal of this is to improve the quality and comfort of workspaces without compromising on energy-saving goals. Due to increasing sustainability requirements, new ways of working and changing office user preferences, there is a growing need for office renovations that not only deal with the energy performance and the replacement of building facilities, but also the occupants’ health and well-being. The renovation of office buildings can substantially reduce energy demand and improve building performance. For this reason, most studies regarding office renovations have focused on achieving better energy performance and indoor environmental quality. Also, several studies have investigated employee satisfaction in the work environment. However, the users are only considered after the buildings have been built and taken into use (e.g., postoccupancy evaluation), but not in the early stage of the design phase. Although there are building regulations and norms regarding indoor comfort, no clear design principles or guidelines considering users have been developed for office renovations. Therefore, it is necessary to explore how office users can be included in the early design stage of office renovations to improve their comfort and satisfaction. This led to the following main research question to be answered in this thesis: How can design principles for energy efficient office renovation be developed, based on the evaluation of user satisfaction? To answer to this question, field studies were conducted in 5 office buildings in the Netherlands. The cases consist of four renovated offices and one non-renovated office, originally built in 1960s to 70s. Before conducting empirical studies, a literature was conducted that is implemented in the theoretical framework. Ten parameters for satisfaction, such as thermal comfort, air quality, light, noise, personal control, privacy, concentration, communication, social contact, and territoriality, were defined and were classified based on the findings from 124 items of studies focussing on physical and psychological satisfaction in the work environment. Each chapter and several sub-research questions address these parameters. Based on the findings, a classification of user satisfaction parameters is proposed, including a discussion about an hierarchy of ten parameters. This hierarchy is structured based on theoretical definitions of parameters and its physical, functional, and psychological influences.  For the empirical studies, a multidisciplinary methodology was applied to prioritise the important aspects of office renovations. The various methods for data collection and analyses included examining energy use and the quality of indoor climate after renovation, and investigating the impact of design factors on user satisfaction with thermal, visual, and psychological comfort. The design factors in this research are influential design factors on user satisfaction. These are office layout, orientation, window-to-wall ratio, and desk location. The empirical studies are structured in four parts. Energy consumption As a preliminary study, architects and facility managers were interviewed to identify the building characteristics of renovated offices and energy consumption. Henceforth, the five case studies were conducted. A cross-case-analysis was used to compare the building characteristics of the five case studies. The energy consumption of renovated and non-renovated offices were compared by different energy matrix. In addition, the limitations that hinder the achievement of better energy performance, were described. Indoor climate and users’ thermal comfort Indoor temperature and humidity were measured by using data loggers to identify the condition of the indoor climate for users’ thermal comfort after renovation. A questionnaire, including thermal sensation, preference, and satisfaction, was distributed among the building users. The monitored climate data of the thermal conditions were evaluated based on the Dutch building norms and users’ responses. Personal control This part aims to identify the relationship between the degree of personal control over indoor environmental conditions (e.g., temperature, ventilation, light) and user satisfaction with thermal and visual comfort. This study investigated the impact of personal control on user satisfaction through user surveys and statistical analyses. The results present that higher controllability leads to more satisfaction in terms of thermal and visual comfort. It also reveals the psychological impact of personal control on user satisfaction by showing differences in perceived satisfaction according to ‘no control’ and ‘do not have’. These findings provide support to workplace management and the design of personal environmental control systems. User satisfaction with thermal, visual, and psychological comfort Together with the indoor climate conditions of workspaces, 579 office users from the five cases were studied. The responses of the users were collected and analysed through statistical analyses. This study phase demonstrates the results of the impact of influential office design factors on user satisfaction with thermal, visual, and psychological comfort. It also contributes to predicting which design variables may bring better user satisfaction. After the empirical studies, the conceptual study was conducted through energy simulation to evaluate the impact of the combination of design factors on the energy demand. Twenty-four office model variants were created based on the combination of design factors, which are consisted of 3 or 4 variables. The energy demand is predicted according to the office model variants. As a next step, the design principles were developed by incorporating the previous findings and various perspectives of energy-efficient office renovation. An overview of the predicted user satisfaction and energy demand is graphically provided in this research. Based hereupon, a flow chart is created for applying the principles to the renovation process. First, the most influential design factors on thermal, visual, and psychological satisfaction are suggested in the design principles. Next, the values of predicted user satisfaction and energy demand can be evaluated by following the flow chart, to find the optimal renovation plan. In this step renovation alternatives are suggested in terms of office variants to create a balance between user satisfaction and energy efficiency. Last, if design limitations occur, the degree of personal control should be included to increase user satisfaction. The comprehensive design principles can help architects, designers, and facility managers to make design decisions in an early stage of office renovations. To summarise, this research demonstrates the relationship between design factors, indoor climate and user satisfaction, without neglecting the fundamental goal of office renovation: reducing the energy demand, upgrading facilities, and improving building performance. It also contributes to developing design principles for office renovations with integrated user perspectives, that improve users’ satisfaction and comfort, as well as energy efficiency. Although users’ individual control over the indoor environment has a significant impact on satisfaction, it needs to be explored further. In addition, it is important to mention that other variables such as building elements and various façade configurations need to be included in further research. In conclusion, design principles considering both energy efficiency and user satisfaction will not only contribute to an increase in the value of a building, but also serve as a stepping stone for user-focused office designs or user-related aspects of the built environment

Energy-Efficient Office Renovation

This research aims to develop user-focused design principles for energy-efficient office renovations. The goal of this is to improve the quality and comfort of workspaces without compromising on energy-saving goals. Due to increasing sustainability requirements, new ways of working and changing office user preferences, there is a growing need for office renovations that not only deal with the energy performance and the replacement of building facilities, but also the occupants’ health and well-being. The renovation of office buildings can substantially reduce energy demand and improve building performance. For this reason, most studies regarding office renovations have focused on achieving better energy performance and indoor environmental quality. Also, several studies have investigated employee satisfaction in the work environment. However, the users are only considered after the buildings have been built and taken into use (e.g., postoccupancy evaluation), but not in the early stage of the design phase. Although there are building regulations and norms regarding indoor comfort, no clear design principles or guidelines considering users have been developed for office renovations. Therefore, it is necessary to explore how office users can be included in the early design stage of office renovations to improve their comfort and satisfaction. This led to the following main research question to be answered in this thesis: How can design principles for energy efficient office renovation be developed, based on the evaluation of user satisfaction? To answer to this question, field studies were conducted in 5 office buildings in the Netherlands. The cases consist of four renovated offices and one non-renovated office, originally built in 1960s to 70s. Before conducting empirical studies, a literature was conducted that is implemented in the theoretical framework. Ten parameters for satisfaction, such as thermal comfort, air quality, light, noise, personal control, privacy, concentration, communication, social contact, and territoriality, were defined and were classified based on the findings from 124 items of studies focussing on physical and psychological satisfaction in the work environment. Each chapter and several sub-research questions address these parameters. Based on the findings, a classification of user satisfaction parameters is proposed, including a discussion about an hierarchy of ten parameters. This hierarchy is structured based on theoretical definitions of parameters and its physical, functional, and psychological influences.  For the empirical studies, a multidisciplinary methodology was applied to prioritise the important aspects of office renovations. The various methods for data collection and analyses included examining energy use and the quality of indoor climate after renovation, and investigating the impact of design factors on user satisfaction with thermal, visual, and psychological comfort. The design factors in this research are influential design factors on user satisfaction. These are office layout, orientation, window-to-wall ratio, and desk location. The empirical studies are structured in four parts. Energy consumption As a preliminary study, architects and facility managers were interviewed to identify the building characteristics of renovated offices and energy consumption. Henceforth, the five case studies were conducted. A cross-case-analysis was used to compare the building characteristics of the five case studies. The energy consumption of renovated and non-renovated offices were compared by different energy matrix. In addition, the limitations that hinder the achievement of better energy performance, were described. Indoor climate and users’ thermal comfort Indoor temperature and humidity were measured by using data loggers to identify the condition of the indoor climate for users’ thermal comfort after renovation. A questionnaire, including thermal sensation, preference, and satisfaction, was distributed among the building users. The monitored climate data of the thermal conditions were evaluated based on the Dutch building norms and users’ responses. Personal control This part aims to identify the relationship between the degree of personal control over indoor environmental conditions (e.g., temperature, ventilation, light) and user satisfaction with thermal and visual comfort. This study investigated the impact of personal control on user satisfaction through user surveys and statistical analyses. The results present that higher controllability leads to more satisfaction in terms of thermal and visual comfort. It also reveals the psychological impact of personal control on user satisfaction by showing differences in perceived satisfaction according to ‘no control’ and ‘do not have’. These findings provide support to workplace management and the design of personal environmental control systems. User satisfaction with thermal, visual, and psychological comfort Together with the indoor climate conditions of workspaces, 579 office users from the five cases were studied. The responses of the users were collected and analysed through statistical analyses. This study phase demonstrates the results of the impact of influential office design factors on user satisfaction with thermal, visual, and psychological comfort. It also contributes to predicting which design variables may bring better user satisfaction. After the empirical studies, the conceptual study was conducted through energy simulation to evaluate the impact of the combination of design factors on the energy demand. Twenty-four office model variants were created based on the combination of design factors, which are consisted of 3 or 4 variables. The energy demand is predicted according to the office model variants. As a next step, the design principles were developed by incorporating the previous findings and various perspectives of energy-efficient office renovation. An overview of the predicted user satisfaction and energy demand is graphically provided in this research. Based hereupon, a flow chart is created for applying the principles to the renovation process. First, the most influential design factors on thermal, visual, and psychological satisfaction are suggested in the design principles. Next, the values of predicted user satisfaction and energy demand can be evaluated by following the flow chart, to find the optimal renovation plan. In this step renovation alternatives are suggested in terms of office variants to create a balance between user satisfaction and energy efficiency. Last, if design limitations occur, the degree of personal control should be included to increase user satisfaction. The comprehensive design principles can help architects, designers, and facility managers to make design decisions in an early stage of office renovations. To summarise, this research demonstrates the relationship between design factors, indoor climate and user satisfaction, without neglecting the fundamental goal of office renovation: reducing the energy demand, upgrading facilities, and improving building performance. It also contributes to developing design principles for office renovations with integrated user perspectives, that improve users’ satisfaction and comfort, as well as energy efficiency. Although users’ individual control over the indoor environment has a significant impact on satisfaction, it needs to be explored further. In addition, it is important to mention that other variables such as building elements and various façade configurations need to be included in further research. In conclusion, design principles considering both energy efficiency and user satisfaction will not only contribute to an increase in the value of a building, but also serve as a stepping stone for user-focused office designs or user-related aspects of the built environment

Managing Tenant Movement scenarios based on Tenant Satisfaction during Occupied Renovation Activities

학위논문 (석사)-- 서울대학교 대학원 공과대학 건축학과, 2017. 8. 이현수.The demands for renovation works in Korean construction market are expected to increase due to the advantages it brings. The two main classification of renovation methodologies are non-occupied condition and the occupied condition. The occupied condition allows the tenants to occupy the building during the construction, while non-occupied condition defines the complete vacancy of the building. The advantage of occupied condition, which the research focuses on, includes rental income collected during the renovation, retaining the tenant, and retaining the customer in the leasing market. The disadvantage of the occupied conditioned renovation includes durational disadvantages compared to the vacant building and considerations of the tenant within the building during the activity. During the occupied renovation, the time-cost tradeoff between finishing renovation quickly and obtaining rental income from partially occupied building necessitates an optimal solution. To optimize the solution, previous researches have focused on the optimization of the time-cost trade off using various analysis. During the analysis, case studies have shown that tenant satisfaction caused delays due to the movement of building user within the building. Since it is inevitable to create space for the workers without removing the tenants, managing tenant satisfactions requires detailed management skills. The tenant dissatisfaction that the renovation causes can result in schedule delay, cost overrun, and loss of building users productivity, which also creates Trade-off between tenant satisfaction, cost, and schedule. The research addresses occupant satisfaction as a main factor that hinders the occupied renovation and takes the satisfaction in to simulation input while scheduling the project. The research provides the building owner the tenant movement scenarios during the renovations works that considers occupant satisfaction as the most important factor.Chapter 1. Introduction 1 1.1. Research Background 1 1.2. Research Objective and Scope 9 1.3. Research Process 10 Chapter 2. Preliminary Study 11 2.1. User Satisfaction in renovation of occupied condition 12 2.2. Occupied Renovation scheduling 15 2.3. Identifying Occupant Interaction (IOI) Method 17 2.4. Agent Based Modeling (ABM) Method 24 2.5. Summary 26 Chapter 3. Development of Tenant Management Model 27 3.1. Tenant Satisfaction abstraction in the Model 30 3.2. Modeling the tenants 33 3.3. Modeling the building environment 36 3.4. Output derivation process of the final schedule 38 3.5. Summary 40 Chapter 4. Result analysis and verification 42 4.1. Comparing the results and verification 44 4.2. Summary 46 Chapter 5. Conclusions 47 5.1. Result and Discussion 48 5.2. Contribution and Limitation 49 Bibliography 50 Abstract in Korean (국문 초록) 54Maste

Using 4D BIM in the Retrofit Process of Social Housing

There is a large stock of solid wall homes in the UK presenting poor thermal insulation and low energy performance. Although the UK Government has supported improvement efforts in the area, the identification of appropriate technical solutions that effectively improve the existing stock remains a challenge. BIM offers opportunities for building performance optimisation, through improved design and simulation. This research investigates how BIM could improve the retrofit process for social housing. This paper describes a research project looking into the use of BIM to develop what-if scenarios for retrofitting existing ’no-fines’ solid wall homes. The scenarios enable the analysis of alternative solutions considering costs, energy performance and user disruption. More specifically, this paper focuses on the use of 4D models to evaluate disruption for end users. The research process includes simulations, meetings, interviews, documents, and observations. Results indicate that the development of 4D BIM models supports a better understanding of the retrofitting process on site, enabling the definition of production processes with as minimal disruption as possible for users, whilst still delivering energy-oriented and cost effective solutions

Detailed Case Studies

Wireless body area networks (WBANs) are one of the key technologies that support the development of pervasive health monitoring (remote patient monitoring systems), which has attracted more attention in recent years. These WBAN applications requires stringent security requirements as they are concerned with human lives. In the recent scenario of the corona pandemic, where most of the healthcare providers are giving online services for treatment, DDoS attacks become the major threats over the internet. This chapter particularly focusses on detection of DDoS attack using machine learning algorithms over the healthcare environment. In the process of attack detection, the dataset is preprocessed. After preprocessing the dataset, the cleaned dataset is given to the popular classification algorithms in the area of machine learning namely, AdaBoost, J48, k-NN, JRip, Random Committee and Random Forest classifiers. Those algorithms are evaluated independently and the results are recorded. Results concluded that J48 outperform with accuracy of 99.98% with CICIDS dataset and random forest outperform with accuracy of 99.917, but it takes the longest model building time. Depending on the evaluation performance the appropriate classifier is selected for further DDoS detection at real-time

Multi-stage calibration of the simulation model of a school building through short-term monitoring

The increasing attention on the improvement of new and existing buildings’ performance is emphasizing the importance of the reliability of the simulation models in predicting the complexity of the building behaviour and, consequently, in some advanced applications of building simulation, such as the optimization of the choice of different Energy Efficiency Measures (EEMs) or the adoption of model predictive control strategies. The reliability of the energy model does not depend only on the quality and details of the model itself, but also on the uncertainty related to many input values, such as the physical properties of materials and components, the information on the building management and occupation, and the boundary conditions considered for the simulation. Especially for the existing buildings, this kind of data is often missing or characterized by high uncertainty, and only very simplified behavioural models of occupancy are available. This could compromise the optimization process and undermine the potential of building simulation. In this context, the calibration of the simulation model by means of on-site monitoring is of crucial importance to increase the reliability of the predictions, and to take better decisions, even though this process can be time consuming. This work presents a multi-stage methodology to calibrate the building energy simulation by means of low-cost monitoring and short-term measurements. This approach is applied to a Primary School in the North-East of Italy, which has been monitored from December 2012 to April 2014. Four monitoring periods have been selected to calibrate different sets of variables at a time, while the validation has been carried out on two different periods. The results show that even if less than 8 weeks have been considered in the proposed calibration approach, the maximum error in the estimation of the temperature is less than ±0.5 in 77.3% of the timesteps in the validation period

Multi-stage calibration of the simulation model of a school building through short-term monitoring

The increasing attention on the improvement of new and existing buildings' performance is emphasizing the importance of the reliability of the simulation models in predicting the complexity of the building behaviour and, consequently, in some advanced applications of building simulation, such as the optimization of the choice of different Energy Efficiency Measures (EEMs) or the adoption of model predictive control strategies. The reliability of the energy model does not depend only on the quality and details of the model itself, but also on the uncertainty related to many input values, such as the physical properties of materials and components, the information on the building management and occupation, and the boundary conditions considered for the simulation. Especially for the existing buildings, this kind of data is often missing or characterized by high uncertainty, and only very simplified behavioural models of occupancy are available. This could compromise the optimization process and undermine the potential of building simulation. In this context, the calibration of the simulation model by means of on-site monitoring is of crucial importance to increase the reliability of the predictions, and to take better decisions, even though this process can be time consuming. This work presents a multi-stage methodology to calibrate the building energy simulation by means of low-cost monitoring and short-term measurements. This approach is applied to a Primary School in the North-East of Italy, which has been monitored from December 2012 to April 2014. Four monitoring periods have been selected to calibrate different sets of variables at a time, while the validation has been carried out on two different periods. The results show that even if less than 8 weeks have been considered in the proposed calibration approach, the maximum error in the estimation of the temperature is less than ±0.5 in 77.3% of the timesteps in the validation period

Reducing the performance gap using calibrated simulation models

Buildings have a significant impact on the environment. Construction of buildings and their operation accounts for 36% of global final energy use and 40% of energy‐related carbon dioxide (CO2) emissions. Also, as per the 2019 International Energy Agency (IEA) and United Nations Environment Programme (UNEP) report, the building sector has a strong potential to provide long-term energy and greenhouse gas emission savings without high financial costs. Building performance simulation tools, ranging from steady-state calculations to dynamic simulation methods, can calculate the anticipated energy consumption of a building with adequate levels of accuracy. However, there is considerable evidence to suggest that buildings underperform post-completion when compared against the expected performance prediction during the design-stage. The difference between the actual operation and the design intent is termed the ‘performance gap’. While the energy performance gap in buildings is a well-known phenomenon, its in-use interpretation is quite vague. It is important to understand the basis of assumptions and protocols used in design-stage performance calculations to assess the causes of the performance gap. In the context of the performance gap, energy performance is generally the most emphasised. The gap, however, is not limited to energy – it also applies to indoor environmental quality (IEQ) parameters, such as temperature and air quality. Moreover, the pursuit of energy efficiency may have the unintended consequence of compromising IEQ, thereby requiring a comprehensive approach to performance assessment. It is therefore important to consider energy and IEQ performance issues together. This thesis contributes to an improved understanding, quantification and resolution of performance gap related issues by using a novel simulation-based approach that enables systematic identification and classification of the root causes of the performance gap. A new measurement and verification (M&V) framework that is underpinned by building performance simulation and calibration is proposed. A key aspect of this new methodological framework is the identification and separation of the three types of performance gaps because of: 1. Use of inappropriate design-stage calculation methods (such as those used for regulatory compliance), 2. Technical issues with the building, its systems and their operations, and 3. Operational changes that the building has gone through to meet its functional requirements. For the first type of performance gap, CIBSE TM54 (CIBSE, 2013a) already provides guidance to reduce the perceived gap and enable improved estimates of building performance during the design-stage. This thesis focuses on the understanding of operational-stage issues and their detailed causes, related to the second and third types of the performance gap. This thesis is the first study that systematically defines, identifies and separates, • the technical issues that cause the performance gap between design intent and actual operation, and • the deviations of operating conditions from the design that are driven by the building’s function and occupancy. This is achieved by integrating the conventional post-occupancy performance assessment approach with building performance modelling and evidence-based model calibration. Another addition to the conventional approach, explored in this study, is the incorporation of IEQ. The issue of IEQ is addressed in two ways: first, by using zonal temperatures for calibration cross-validation, and second, by assessing the energy-related unintended consequences of IEQ underperformance which may happen during building operations. The calibrated simulation models are operationally accurate virtual representation of the actual building and can help to isolate the performance issues and validate the findings. The new framework proposed in this thesis is better suited than conventional M&V protocols such as ASHRAE (American Society of Heating Refrigerating and Air Conditioning Engineers) Guideline 14 and IPMVP (International Performance Measurement and Verification Protocol). These conventional M&V protocols also propose a calibration-based approach, but they generally focus on broad statistical requirements and are not tied to a framework for a procedural verification of all the most important issues that can cause the performance gap. It is likely that using these conventional protocols will identify some key issues during investigations while leaving other potential issues hidden. The guidance on calibration and validation provided in conventional M&V protocols is commonly used for all model calibration exercises. However, the conventional protocols were developed for calculating energy savings in retrofit applications, and the calibration criteria defined in them are mainly for checking the accuracy of building-level energy use totals. The calibration criteria do not check for the uncertainty or the accuracy of dependent parameters, such as zone temperatures and other environmental outputs, which could cross-validate the model. Mathematically, meeting just the statistical criteria for building-level energy use totals in a highly parameterized model and an under-determined search space can lead to unrealistic solutions also being validated. To better support the calibration accuracy with the new proposed M&V framework, advanced model validation criteria have also been developed. New multi-level calibration criteria are proposed, which factors in data quantity, quality and granularity. In this new advanced validation criteria, the current industry standard of monthly energy use checks is the lowest level of calibration, with higher levels requiring detailed checks, using granular and disaggregated energy use. However, all levels of calibration require minimum dependent parameter checks, such as IEQ checks for typical zone temperatures. Dependent parameter checks are desirable in model calibration; however, current statistical criteria used for calibration are not suitable for these checks. Revised and new metrics and thresholds are proposed and explored in this thesis for use in advanced calibrated model validation checks. Beyond the use of IEQ parameters (e.g. zone temperatures) in model calibration, another area of focus of this thesis is the unintended IEQ underperformance captured during the monitoring. The scope of this assessment is limited to underperformance in IEQ parameters linked to achieving high energy efficiency objectives, thermal comfort and indoor air quality (IAQ). Amongst the various IEQ parameters, thermal comfort and IAQ have complex and dynamic interactions with buildings energy end-uses. Comprising of multiple factors, which are both subjective and empirical, thermal comfort and IAQ performances have a high interrelation with the energy performance objectives. Therefore, along with conventionally tracked parameters of temperature and CO2, additional IAQ parameters (not used during the calibration process), such as NO2, PM2.5 and PM10, are analysed to enhance the understanding of unintended energy-related IEQ underperformance. The new methodology proposed in this study is applied to five case study buildings across four building sectors – offices, schools, hospitals and apartment blocks. These buildings represent a large cross-section of the UK building stock and, therefore, can provide useful insights into the issues in the construction sector that drive the performance gap. While detailed performance assessment and advanced validation is done for all five case study buildings using the proposed framework, in one case study building the multi-level calibration checking criteria is also fully explored. Using this methodology on the various case study buildings, cross-sectoral lessons, related to root causes of the energy performance gap and applicable in the wider industry context, are uncovered. Linking to the three types of performance gaps mentioned earlier, analysis of the results shows that, in most of the case studies, some of the energy performance gap is the perceived gap (related to point 1: use of inappropriate design-stage calculation methods) or is because of operational changes (related to point 3: changes that the building has gone through to meet its functional requirements). However, the most critical cause of the gap is due to technical issues (related to point 2: issues with the building, its systems and their operations) identified across the case studies. These issues were either design errors, improper construction and installation, poor commissioning or shortcomings in building systems and the use of new low-carbon technologies. It was observed that long-term involvement (with responsibility for the operational performance) of the design and construction teams are effective in lowering performance gaps. Issues related to IEQ were also observed across the case studies, such as overheating risks and poor IAQ. These added to the existing knowledge of energy-related IEQ issues and highlighted the need to address IEQ simultaneously with energy through better design, advanced operational controls and by incorporating regular IEQ measurements as part of operations and maintenance protocols. The novel approach presented here builds a case to move building performance calculations towards an operational context, where design projections are done using advanced simulation and with a view of tracking the projections through to operation using measurable performance outcomes. Overall, the study shows the importance of the early involvement of all stakeholders and their accountability to minimise performance issues. Integrating the findings from the case studies, a case could be built for having IEQ performance objectives in energy performance contracts. This can mitigate the trade-offs of IEQ against energy performance that leads to unintended health consequences for occupants. Further, this work promotes a way of integrating dynamic thermal simulation in regular post-occupancy checking and management of buildings