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• Combining several different heating devices in a hybrid installation is possible. • The RES share in heat production in hybrid installation may be significant. • The passive cooling mode of heat pumps is highly energy-efficient. • The efficiency of the ground heat pump in heating mode ranged from 3.5 to 3.8. The article presents long-term results of experimental tests of a hybrid installation (HI) consisting of four heating devices, three of which use renewable energy sources (RES). The HI is operating in a residential and retail building located near Kraków, in southern Poland. There is little experience with the operation of such installations, therefore, the purpose of this paper is to discuss significant aspects related to the implementation and operation of HI in a moderate, transitory climate. The research was carried out from 2011 to 2017. The share of solar collectors in annual heat generation ranged between 7.4% and 12.5%, with an average annual efficiency to 38%. The annual performance of a ground-source heat pump in the heating mode ranged from 3.5 to 3.8, and in the passive cooling mode, it reached up to 11.87. The annual efficiency of a gas condensing boiler was from 77.5% to 82.2%. Annually, the largest amounts of heat were supplied by a biomass boiler i.e. from 30% to as much as 50%. The paper disclosed clearly that it is possible to reach in HI high level of RES share in heat generation. A key issue requiring further research is the development of appropriate algorithms in the control systems of HI. [ABSTRACT FROM AUTHOR]

This paper analyzes electricity use in buildings and explores key research questions related to assessing, rating, labeling, and benchmarking building energy use. The analysis reviews annual Energy Use Intensity (EUI) data from 3060 fully electric-powered buildings across six categories: residential, educational, offices, hospitals, hotels and restaurants, and wholesale and retail trade services. One-fifth of the analyzed buildings is derived from an energy dataset that offers a higher time-scale resolution, providing more detailed insights into energy usage patterns. The analysis employs various factors, including the seasonal variation factor (SVF), daily variation factor (DVF), monthly factor (M f), and hourly factor (H f), to gain a detailed understanding of actual energy usage at different time scales. The findings indicate that electricity use is less sensitive to seasonal variations than other energy carriers that provide heating and cooling. The paper provides hourly and monthly peak load percentages (PPL), which can indirectly assist in assessing hourly schedules for building energy performance simulations. The monthly energy use pattern varies between building categories, with high-energy months alternating between winter and summer. For non-residential buildings, high-energy hours correspond directly to the daytime, while for residential buildings, there is a shift towards the evening, and the daily amplitude is lower. Furthermore, the analysis of daily and monthly variability of heating energy carriers, even if non-electric, sheds light on the implications of electrification for these loads. • The study evaluates annual electricity data from 3060 fully electric-powered buildings. • Median EUIs are meaningful energy performance benchmarks by building category. • Residential and educational buildings exhibit EUIs of 90-120 kW h/m2. • Offices and hospitals demonstrate EUIs of 160-170 kW h/m2. • Monthly and hourly factors establish energy benchmarks for finer time resolution. [ABSTRACT FROM AUTHOR]

• Overheating regulations and calculation methods in 26 European countries were compared. • Most of the existing calculation methods are outdated and do not fit climate-proof buildings. • France requires a mixed-mode operation of naturally ventilated households. • The UK developed a heatwave-based calculation approach. • Comfort-based, multi-zonal, and time-integrated calculation approaches are needed. With the ongoing significance of overheating calculations in the residential building sector, building codes such as the European Energy Performance of Building Directive (EPBD) are essential for harmonizing the indicators and performance thresholds. This paper investigates Europe's overheating calculation methods, indicators, and thresholds and evaluates their ability to address climate change and heat events. e study aims to identify the suitability of existing overheating calculation methods and propose recommendations for the EPBD. The study results provide a cross-sectional overview of twenty-six European countries. The most influential overheating calculation criteria are listed the best approaches are ranked. The paper provides a thorough comparative assessment and recommendations to align current calculations with climate-sensitive metrics. The results suggest a framework and key performance indicators that are comfort-based, multi-zonal, and time-integrated to calculate overheating and modify the EU's next building energy efficiency regulations. The results can help policymakers and building professionals to develop the next overheating calculation framework and approach for the future development of climate-proof and resilient residential buildings. [ABSTRACT FROM AUTHOR]

Abstract Due to their significant internal heat gain resulting from computer server banks, data centres require cooling year-round, creating an opportunity to transport the waste heat to heat-deficient neighbouring buildings. This paper evaluates the quantity of multi-unit residential buildings (MURBs) that should be connected to a given data centre in order to maximize the portion of shared energy which provides the MURBs' heating energy and the data centre's cooling energy simultaneously. The paper then evaluates the financial viability and greenhouse gas (GHG) emissions of three different methods with which energy can be shared from a data centre to surrounding MURBs in a community energy network (CEN). The first method, called the Energy Sharing System involves using a heat pump to produce heating and cooling at the same time for the MURBs and the data centre. The second, called the One-Borefield System, has the same energy sharing aspect as the first, with additional heating and cooling coming from geo-exchange. The third method, called the Two-Borefield System, is an innovative approach to geo-exchange, which uses two separate borefields to achieve free cooling, while also incorporating the energy sharing base. The investigation finds that the optimal MURB area that should be connected to a 4000 kW cooling load data centre is 110,000 m2 for the Toronto (Canada) climate. The financial analysis shows that the Energy Sharing System was the most profitable, with a 11.9% 30-year unlevered after-tax internal rate of return (IRR). [ABSTRACT FROM AUTHOR]

Highlights • A pre and post renovation energy use analysis of almost 90,000 renovated dwellings. • The (p)rebound effects explain only partly disappointing energy renovation results. • Effectiveness of renovations are dependent on state of building prior to renovation. • Effectiveness of renovations are dependent on type of occupant. • Deep renovations often save less energy than expected but are the most effective. Abstract Energy renovations often result in lower energy savings than expected. Therefore, in this study we investigate nearly 90,000 renovated dwellings in the Netherlands with pre and post renovation data of actual and calculated energy consumption. One of the main additions of this paper, compared to previous studies on thermal renovation, is that it only takes dwellings into account with the same occupants before and after renovation, using a large longitudinal dataset. Overall this paper shows new insights towards the influence of the energy efficiency state of a building prior to energy renovation, the type of building, the number of occupants, the income level of the occupants and the occupancy time on the actual energy savings, the energy saving gap and on the probability of lower energy savings than expected. We also investigate if the influence is different per type of thermal renovation measure. Some of the findings are: it is impossible to conclude which single thermal renovation measure is the most effective because this is dependent on the energy efficiency of the building prior to the energy renovation, type of building, income level and occupancy; occupants with a high income save more energy than occupants with low income; dwellings with employed occupants benefit more from improved building installations than dwellings occupied by unemployed occupants; The prebound and rebound effects are only part of the explanations for lower than expected energy savings; Deep renovations result more often in lower than expected energy savings than single renovation measures but nevertheless they result in the highest average energy saving compared to other thermal renovation measures. The results could be used for more realistic expectations of the energy reduction achieved by thermal renovations, which is important for (amongst others) policy makers, clients and contractors who make use of energy performance contracting, home owners, landlords and (social) housing associations and as a starting point to improve the energy calculation method. [ABSTRACT FROM AUTHOR]

Life Cycle Assessment (LCA) is increasingly used as an early-stage design-decision tool to support choices of structural system. However LCA modellers must first make numerous methodological decisions, and the resultant wide variations in approach are often inadequately described by the modellers. This paper identifies, and quantifies, the three major areas of methodological variation. These are: temporal differences in the stages considered; spatial differences in the material boundaries; and physical disparities in the data coefficients. The effects are then demonstrated through a case study of a student residential building in Cambridge. The cross-laminated timber (CLT) structure is compared with concrete frame, steel frame and load-bearing masonry, considering the influence that varying the temporal boundaries, the data coefficients, and the spatial boundaries has on the choice. While for this building CLT is confirmed as the lowest impact material, the paper demonstrates that varying the methodological choices can change the results by an alarming factor of 10 or even more. The findings confirm the need for the utmost clarity and transparency with all LCA calculations. Making wider industry or policy decisions based on LCA results should be undertaken with extreme caution. [ABSTRACT FROM AUTHOR]

Users’ behaviour and indoor climate are two leading aspects that must be taken into account if we want the retrofitting of the housing stock to contribute to CO 2 reduction, comfort improvement and reduction of living costs. The integrated facade module evaluated in this paper, which constitutes an approach to zero energy renovation, includes a preliminary study for the identification of target occupants and their characteristics and requirements that will guide the design decisions. The proposed strategy primarily focuses on the case of social rental multi-family housing stock in the Netherlands, but should provide insights in the application of the concept in Europe. This paper presents the analysis of the adaptability of this solution to the Mediterranean climate, taking into account the specific characteristics of the occupants of this climatic zone. The results showed an improved performance of building after the application of the evaluated solution in southern Spain, but with lower savings on the energy demand than in the Netherlands, so the economic investment should be reduced in this case. Also, the inclusion in the solution of some variables, such as the forced night-time ventilation for passive cooling and the insulation thickness reduction, were tested and proved to be an optimisation of its performance in the Mediterranean climate. Overall, the study concluded that the proposed refurbishment strategy has the potential to be implemented in different climates, particularly if certain modification in the facade operation is considered. [ABSTRACT FROM AUTHOR]

The objective of this paper is to optimize the passive design of newly-built residential buildings in hot summer and cold winter region of China for improving indoor thermal comfort while reducing building energy demand. In this respect, this paper investigates the performance of a representative apartment building in the city of Shanghai and evaluates the optimum solutions by using a developed optimization approach, which includes three major steps of 1) setting the model for multi-objective optimization, 2) sensitivity analysis for reducing the dimension of input variables, and 3) multi-objective optimization by using the Non-dominated Sorting Genetic Algorithm II (NSGA-II) coupled with the Artificial Neural Network (ANN), among which a novel indicator for evaluating the annual indoor thermal comfort of residential buildings of Shanghai named Comfort Time Ratio (CTR) is defined based on the modification of Szokolay’s theory in terms of bioclimatic analysis, and the impacts of passive design variables on the indoor thermal comfort and building energy demand in terms of different directions are comprehensively investigated. Results of the multi-objective optimization indicate that the residential buildings of Shanghai have a great potential in comfort-improvement and energy-saving. A series of novel optimal passive design tactics for residential buildings in Shanghai are derived accordingly which could be easily understood and conveniently carried out by the architects in practice. [ABSTRACT FROM AUTHOR]

The aim of this paper is to evaluate and illustrate the energy saving potential of the façade addition on existing and low energy performing block buildings in different climatic contexts. To achieve this purpose, the paper illustrates some outstanding case studies on deep renovation through façade and volumetric additions, as reference possible solutions towards energy renovation. To further assess the energy potential of these transformations, the same solutions have been applied to a reference building in Bologna. In particular, a selected apartment of typical building block has been investigated and simulated in detail, to identify the buildings’ energy requirement and propose different retrofitting hypotheses towards nearly Zero Energy Buildings (nZEBs). Simulations of these different hypotheses resulted in corresponding diverse energy performances, from the very low grade of performance in “as built” scenario, up to nearly zero energy demand, for selected technological solutions applied in specific climatic contexts. To further estimate the energy impact the same apartment has been “extracted” from its original climatic context and energy simulations have been also carried out in two different climatic zones. Obtained results prove that façade additions are a very powerful solution towards the aim of zero energy in existing buildings. [ABSTRACT FROM AUTHOR]

[Display omitted] • Building policies must be rooted in a good understanding of the targeted population. • Building performance standards may benefit from creating databases of weather files. • A thermal performance analysis should consider multiple key performance indicators. • Building performance policies should address the thermal resilience of buildings. This paper presents the main challenges faced and lessons learned when developing a new method to assess the thermal performance of residential buildings for the recently updated Brazilian building performance standard, NBR 15575–1:2021. It touches on subjects related to the representation of occupant behavior, climate, and thermal acceptability in building performance simulation, as well as the use of reference models, key performance indicators, and performance levels in policies. NBR 15575 provides a thorough procedure to analyze thermal performance, allowing buildings to be assessed while in passive operation mode and also accounting for energy needs when active operation is necessary. Multiple key performance indicators are introduced to provide a comprehensive evaluation. The main difficulty found was dealing with diversity. Given the vast scale of Brazil's territory, a high variation in culture, climate and construction techniques is expected, thus requiring a compromise between detail and scalability. There are still many opportunities for improvement, especially regarding the representation of occupants, and adjustments of the characteristics of reference models to promote high thermal performance, considering the diverse climates, regional practices, and economic needs. This paper might help researchers and other stakeholders to develop and improve other local standards and protocols, especially for warm climates. [ABSTRACT FROM AUTHOR]

Demand-side management methods are expected to play a key role in future energy systems. These methods are making energy demand adaptive to fluctuations inherent to intermittent renewable energy sources. In order to develop feasible demand-side management solutions, a better understanding of the temporality of the energy demand is needed. This paper contributes to this by focusing on the daily load profiles of energy demand for heating of Danish dwellings with heat pumps. Based on hourly recordings from 139 dwellings and employing cluster and regression analysis, the paper explores patterns (typologies) in daily heating load profiles and how these relate to socio-economic and technical characteristics of the included households. The study shows that the load profiles vary according to the external load conditions. Two main clusters were identified for both weekdays and weekends and across load segments; a main cluster with a relatively constant load profile and a minor cluster with a more distinct variation during the day. The difference between the clusters is primarily correlated with building characteristics like floor area, building year and type of space heating distribution system, while the existence of children and teenagers in the household were the only significant socio-economic variables. [ABSTRACT FROM AUTHOR]

[Display omitted] • Unique preconditions, specific characteristics for use can be boundary conditions. • Energy use, users' behavior, lighting are correlated conditions within buildings. • Boundary conditions can help explain the occupants' behaviour and the use of spaces. • Knowledge of boundary conditions helps to understand how to design buildings. • Boundary conditions can be building/ user/ input-values and method-specific. This paper aims to review the boundary conditions (B/C) in specific categories (energy, building use, and lighting) within non-residential buildings to pave the way to a better understanding of users' requirements and needs of the built environment. For this paper, B/C are understood as unique preconditions, specific characteristics for use, determining specific features of buildings, enabling an accurate understanding of non-residential spaces concerning energy use, user behaviour, and lighting. This paper describes the results of an overall quantitative (1st method) review and a systematic review (2nd method) of boundary conditions and their factors within different types of non-residential buildings from the users' perception. Followed by a qualitative experts' literature review (3rd method) on B/C within offices, schools, and hospitals chosen by a team of international experts working together on Subtask A: User perspective and requirements, Task 61 IEA (International Energy Agency): Solutions for daylighting and electric lighting. The first review method led to the selection of 21 papers. The second method resulted in the selection of 7 papers out of 93,143 found in Scopus; during the 3rd review, experts collectively chose 74 additional papers focussing on the users' factors contributing to specific B/C. The scope of this paper is limited only to offices, schools, and hospitals. Based on the findings, the authors recognise a broad definition of boundary conditions from specific values, and conditions to interconnected factors, user profiles, functions of the building types, and operating hours. This paper is an overview of B/C factors found in the literature that can help explain the occupants' behaviour and the use of spaces. B/C are often type of building/user/location/situation/simulation input-values and method-specific. Therefore, they cannot be widely applicable but offer patterns and help to understand the correlations between various factors shaping the built environment. A better comprehension of the reasons for identifying B/C and their factors can help in developing a deeper knowledge of how we use buildings to find optimal ways to design them. [ABSTRACT FROM AUTHOR]

Designing a low energy building requires to evaluate a large number of parameters: design combinations, element thermal characteristics, HVAC systems efficiencies, etc. All of them determine the space heating and space cooling energy demands, energy consumptions, and life cycle cost over the lifetime of the building. This paper presents the achievements of SEDICAE research project consisting on a new methodology based on a tabu search and a simplified method to calculate energy consumptions. The methodology is designed to estimate the annual energy demand, life-cycle cost and energy rating. A second process is included to select the HVAC system is developed for the building designed with this methodology. In general, builders should look for low energy, but investment in building design is a limiting factor. This paper show the relationship between energy efficiency index and investment in optimized residential building. Furthermore, the best energy rate is obtained applying the HVAC systems in the integrated optimization method for residential buildings. This methodology reduces investment, reduce the energy demand and selects the best construction materials, allowing to study the cost in different economic scenarios. In this paper, a building design case study is studied in 2028 scenarios in 12 climatic zone in Spain. [ABSTRACT FROM AUTHOR]

This paper provides an analysis of the appliance ownership and use factors contributing to high electrical energy demand in UK homes. The data were collected during a large-scale, city-wide survey, carried out in Leicester, UK, in 2009–2010. Annual electricity consumption and appliance ownership and use were established for 183 dwellings and an odds ratio analysis used to identify the factors that led to high electricity consumption. Many of the appliance ownership and use factors have not previously been studied for the UK domestic sector. The results of this study should be of key interest to government policy makers and energy supply companies interested in the underlying drivers of the highly positively skewed distribution of UK domestic electricity use. The study identifies those appliances that could be targeted for technical improvements or subjected to campaigns to encourage more energy efficient use in order to reduce electricity consumption among high demand households. This paper builds on earlier work by the current authors which identified the households (socio-demographic and dwelling characteristics) most likely to be high electricity consumers. The current work provides the basis for advice and guidance to those households that would enable them to, over time, reduce their electricity use. [ABSTRACT FROM AUTHOR]

The selection of a thermal comfort model for establishing indoor optimal hygrothermal conditions during the hot period has a major impact on energy consumption of Net Zero Energy Buildings in hot climates. The objective of this paper is to compare the influence of using different thermal comfort models for zero energy buildings in hot climates. The paper compares the impact of applying Fanger's model, Givoni's model, the ASHRAE 55 adaptive comfort model and the EN 15251 adaptive comfort model on energy consumption and comfort performance. Using both the building performance simulation tools ZEBO and EnergyPlus for energy simulation, an existing prototype of a residential apartment module is used to evaluate energy performance and thermal comfort in two parametric series. The first one is the result of coupling natural ventilation and mechanical cooling and the second one is guided coupling natural ventilation, mechanical cooling and ceiling fans. This study shows that the percentage of energy consumption difference meeting the comfort criteria according to ISO 7730 in comparison to EN 15251, ASHRAE 55 or Givoni's model varied up to 16%, 21% and 24.7%, respectively for the presented case study. More energy savings can be expected for buildings in hot climates with greater cooling demands. [ABSTRACT FROM AUTHOR]

The application of large area of glass is still the main utilized strategy to count for the deep-rooted preference for the full external view as well as daylight penetration in residential buildings. However, for the successful renovation of old residential buildings, the application of full-height glass window should be made a major priority. This paper presents a sustainable approach on the current set-up of the multi-apartment renovation process in terms of sustainable lighting. Among the conducted investigations, the paper includes the case study analysis for the experimental applications of a double skin facade aimed at finding out the optimal configurations that could utilize daylighting demands. Also, currently applied mechanisms in the identification and evaluation of daylighting efficiency, data analysis for the measuring of light energy efficiency as well as the processes involved in the determination of daylighting feasibility control for the renovation process utilizing the developed glazed wall are presented in this paper. This paper gives an insight into recommendations and research findings that could be used to further improve this process. [ABSTRACT FROM AUTHOR]

Feature engineering and data-driven classification models are at the forefront of analysis of large temporal sensor data from the built environment. In previous efforts, temporal features were engineered from the whole building hourly electrical meter data from 507 non-residential buildings. These features fall within the three general categories of statistics, model, and pattern-based and can be used to identify various behavior in the structure of the whole building electrical meter data. In this paper, a deeper investigation is made of exactly what types of behavior are most important in the context of two classification scenarios: the primary use of a building and the level of performance the building has when compared to its peers. The highly comparative time-series analysis (hctsa) toolkit is used to analyze the most important temporal features for the classification of various building performance attributes. In the first analysis, a comparison is made to distinguish the behavior between university dormitories (70 buildings) and laboratories (95 buildings) as an example of interpreting the classification of the primary-use-type of a building. In the second analysis, a comparison of buildings with high (165 buildings) versus low (169 buildings) consumption is used to extract and understand the behavior that indicates the level of the energy performance of a building. These two case study examples provide a foundation for further explainable machine learning techniques in both classification and prediction as applied to buildings. This effort is the first example of machine learning with an explicit focus on the interpretability of classification for smart meter data from non-residential buildings. [ABSTRACT FROM AUTHOR]

The acceleration of urbanization and the growth of population are considered to be the reasons of increasing demands for construction, life quality and energy consumption. This leads to more research in climate adaptive strategies such as traditional design methods, construction techniques and building materials. Traditional dwelling has been successful in achieving harmony between dwelling and climatic environment, which is one of the most important conditions for sustainability. Firstly, this paper focused on analyzing the characteristics of traditional dwellings in Qinba mountainous areas to adapt to the climatic environment. Secondly, two typical dwellings constructed respectively with brick and earth materials were selected for monitoring and simulating of its indoor thermal, luminous and ventilation environment in summer and winter. In addition, the research summarized the advantages and disadvantages of the dwelling's physical environment in response to climatic characteristics. It revealed that the traditional earth dwelling is well adapted to the local climate during summer, although the indoor thermal comfort is not fully satisfactory during winter. Finally, we prompted effective climate adaptive strategies of traditional earth dwelling, such as natural ventilation, thermal insulation and thermal buffer space. We want to provide guidance and reference for the development of traditional dwellings in the mountainous areas. [ABSTRACT FROM AUTHOR]

Building energy consumption forecasting is crucial for energy managers and policymakers. However, acutely predicting the energy consumption of any building is more important in energy efficiency benchmarking of buildings. Energy benchmarking is a precise technique for measuring, tracking, and reducing end-use energy usage of buildings by employing comparative scenarios. Bottom-Up energy consumption assessment has been used in several studies to evaluate a collection of buildings' energy performance to a standard. Traditionally, researchers have used a single approach to predict the energy use of buildings and to conduct benchmarking. However, it has been found that doing so frequently compromises the accuracy of the predicted energy use of buildings. It also has an adverse effect on the buildings' energy benchmarking framework results. This paper will provide an energy benchmarking framework for residential buildings based on the blending techniques of multiple approaches. Over 3000 datasets were gathered from the Indian city of Jaipur. In order to analyse the trends in energy consumption, the data were divided into categories based on economic levels. The data is then subjected to some fundamental statistical analysis, along with several approaches are blended to forecast the energy consumption of the buildings with the highest accuracy. These benchmark levels set guidelines for assessing and recognising strong performance while also identifying underperforming buildings and giving them more priority for energy efficiency improvement. The technique may be used for different metropolitan levels and climatic conditions. [ABSTRACT FROM AUTHOR]

• We review sixteen models for Variable Refrigerant Flow System (VRF). • We develop three data-driven models for VRF. • Physics-based and data-driven models are compared on a real-world dataset. • The impacts of different input features on VRF efficiency are analyzed. Variable Refrigerant Flow (VRF) systems are gradually gaining popularity in small and medium-sized commercial and residential buildings owing to their high part-load performance, flexible control, and ease of installation and maintenance. Developing models of VRF systems to predict their performance are important for model-based control, fault diagnostic and detection. There are VRF models published in existing literatures, however those models were developed and validated in different datasets. As a result, the model accuracy cannot be directly compared. To fill this gap, this paper presents a comprehensive review of the existing VRF models, and summarizes the input/output parameters and mathematical formulas of 16 VRF models from literature (referred to as physics-based model). Next, we validate and compare the model accuracy of existing models using the same dataset. Additionally, we develop data-driven models using the state-of-art machine learning algorithms, and compare the model accuracy between existing physics-based models with data-driven models. We find the model proposed by Hu et al. in 2019, which regresses the VRF cooling capacity and COP as a linear combination of indoor and outdoor temperatures times a cubed polynomial function of compressor frequency, is the most accurate physics-based model, with a prediction error of 22.19% in the training dataset and 22.44% in the validation dataset. XGBoost is the most accurate data-driven model, with a prediction error of 19.29% in the training dataset and 22.02% in the validation dataset. The data-driven model is more accurate while the physics-based model is more generalizable. The findings of this study can help researchers to select the proper VRF model for building energy prediction, model-based optimization, and fault diagnostic and detection. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has significantly affected people's behavioral patterns and schedules because of stay-at-home orders and a reduction of social interactions. Therefore, the shape of electrical loads associated with residential buildings has also changed. In this paper, we quantify the changes and perform a detailed analysis on how the load shapes have changed, and we make potential recommendations for utilities to handle peak load and demand response. Our analysis incorporates data from before and after the onset of the COVID-19 pandemic, from an Alabama Power Smart Neighborhood with energy-efficient/smart devices, using around 40 advanced metering infrastructure data points. This paper highlights the energy usage pattern changes between weekdays and weekends pre– and post–COVID-19 pandemic times. The weekend usage patterns look similar pre– and post–COVID-19 pandemic, but weekday patterns show significant changes. We also compare energy use of the Smart Neighborhood with a traditional neighborhood to better understand how energy-efficient/smart devices can provide energy savings, especially because of increased work-from-home situations. HVAC and water heating remain the largest consumers of electricity in residential homes, and our findings indicate an even further increase in energy use by these systems. [ABSTRACT FROM AUTHOR]

• Data about DHW in residential buildings were collected by survey in Southern Italy. • Contextual and personal factors influencing DHW usage were considered. • Descriptive statistics were performed to characterize DHW by climatic zone. • Inferential statistics were conducted to discover DHW usage patterns. • Four clusters of dwellings were identified considering DHW daily usage hours. In European efficient buildings, the share of energy use for DHW is a significant percentage of the heat requirement. The evaluation of DHW energy demand and consumption patterns has been neglected in the past and studies are located in Northern countries. This paper presents a survey conducted in Southern Italy. Descriptive statistics were performed to characterize DHW production by climatic zone. Inferential statistics were conducted to discover significant contextual and personal variables and identify usage groups. The most used energy source was biomass (49.3%), followed by methane gas (37.7%). Fireplaces were installed in the coldest zone, in detached houses, more in small municipalities (36%), and low-income families (32%). Solar systems were in 8% of dwellings having income higher than 28000€. Four clusters of dwellings were identified considering the daily usage hours. The eldest and less numerous households fell into the cluster with the lowest usage (3.5 h). Households with a percentage <25% of unemployed components had more probability to belong to clusters with more DHW usages. The paper contributes to fill the investigation in the Mediterranean area and provides a systematic approach to expand the limited knowledge about the influencing factors on the DHW production and usage. [ABSTRACT FROM AUTHOR]

Abstract Dwellings with no heating, ventilation and air conditioning (HVAC) systems are commonly found in many countries. The long-term thermal performance of these buildings can be assessed based on hourly data of occupant thermal discomfort integrated over the required timespan (e.g. total degree hours of discomfort per year). This approach can be easily applied when simulation is adopted in the assessment, but field studies using this approach are rare as they would require complex, costly and long measurement/survey campaigns. This paper addresses the challenges on conducting field studies on long-term thermal performance of dwellings with no HVAC system by introducing a novel performance indicator: the Seasonal Thermal Sensation Vote (S-TSV). S-TSV adopts the standard 7-point thermal sensation scale and is based on the perceived overall thermal sensation recalled by the user of the building for specific seasons and times of day. The new performance indicator is not intended to replace existing ones, but to complement them in the understanding of the complex thermal performance processes taking place in buildings with no HVAC. S-TSV was applied in a field study targeting a small sample of dwellings in Brazil. Results demonstrate the capabilities of S-TSV to describe trends in buildings performance in this sample. S-TSV also assisted on the identification of relationships between such performance and some independent variables addressed in this field study (e.g. windows operation, footwear and income), considering a threshold of p -values <0.05 on the chi-square statistic test. [ABSTRACT FROM AUTHOR]

Highlights • Studies using questionnaire for collecting energy data in buildings are reviewed. • Investigations are classified according to data collection methods and objectives. • Problems about terminology, identity of recipients, and response rate are highlighted. • The review provides suggestions and guidance on the use of questionnaire. Abstract The paper presents a review of the literature on the use of the questionnaire as a tool for collecting energy data in residential buildings. Numerous studies used the questionnaire to gather necessary information for different purposes. However, even using the same tool, the procedures differ in terms of distribution and compilation, contact with the interviewees and type of proposed questions. One hundred thirty-seven studies were considered in the review, including both scientific articles and surveys reports. The available works were analysed and classified according to the geographical origin, period, sample size, sample structure, data collection methods, response rate, data processing, and objectives of the investigation. In the 80% of the selected studies, the questionnaire is used as unique tool for data collection, albeit cases in which the questionnaire is coupled with other survey techniques, such as field measurements and time use surveys, have also been recorded. The in-person interview is the most common completion option in the sample and it is also the method that produces the highest response rate (77.6%). Generally, the collected data are subjected to statistical processing (over 80% of the cases). Regarding the objective of the surveys, the questionnaire is mainly employed for investigations on energy consumption and occupants' behaviour, but also other purposes were identified. Overall, the revised sample and the experiences reported are largely varied and heterogeneous. The lack of a homogeneous methodology appears in the use of an extremely diversified terminology. Therefore, the codification of a reference method and the standardisation of the nomenclature would be desirable. It would be useful to define general guidelines to be followed when designing surveys by using questionnaires. The review provides some suggestions and guidance on the use of questionnaire, highlighting strengths and weaknesses, and represents a source of information for future researches focused on the energy performance of buildings. [ABSTRACT FROM AUTHOR]

Highlights • The weighted average values of thermal energy consumption (oil and natural gas) for space heating, as of 2011, of the complete stock of buildings in Greece used as primary residences (insulated or not, single-dwellings or apartments), is estimated to 60.9 up to 130.1 KWh·m−2·year−1. • The mean actual thermal energy consumption for space heating of residential buildings is much lower than that evaluated based on HDHs or the method of Hellenic Building Energy Performance Regulation (REPB), according to European Directive 31/2010. • The implementation of the Hellenic regulation for building energy performance (REPB) imposed the improvement of thermal protection of the building envelope and the performance of the electrical and mechanical systems. • Applying the REPB minimum requirements on thermal protection reduce the space heating loads of residential buildings in all climate zones by 63% to 70%. The compliance of existing residential buildings to the minimum requirements of the REPB could result to about 24.4 TWh of savings in space heating energy annually. • The benefits of any National Regulation on Building Energy Performance should be examined on the basis of expected lower actual energy consumption. Abstract This paper presents the energy, the technical and the environmental characteristics of residential buildings in Greece, as well as their potential for energy conservation, based on their actual energy consumption data. The technical characteristics of residential buildings related to their energy performance (insulation, type of openings, system for space heating and cooling, etc.), the actual energy use (kWh.m−2.year−1) and the environmental factors (kgCO₂.m−2.year−1) related to energy consumption, are some of the parameters of this survey. The average annual specific energy consumption of residential buildings in Greece was 112 kWh·m−2·year−1 in 2014, the 6th lower consumption among the 28 European member states (EU-28) in which the average residential building energy consumption is of about 158.8 kWh·m−2·year−1. The potential of space heating energy conservation for Greek residential buildings was estimated, based on (i) the 2011 heating energy consumption data and (ii) the percentages of space heating energy conservation, calculated by analysing 144 different types of residential buildings, having various geometric and technical characteristics, such as the A/V ratio (envelope area to volume of building), the heating degree hours (HDHs) and various occupancy profiles. The resulting average actual energy consumption is much lower than that calculated using Heating Degree Hours (HDHs) or the method of Hellenic Building Energy Performance Regulation (REPB). Almost 45% of these buildings were built before 1980, without any thermal insulation or double glazing. The compliance of these buildings to the minimum requirements of the REPB (related to thermal insulation and the efficiency of their electromechanical systems), could result to about 24.4 TWh of savings in space heating energy annually, i.e. to about 32–175 kWh·m−2·year−1, depending on the climate zone that corresponds to 8.5–46.2 kgCO₂·m−2·year−1 reduction. [ABSTRACT FROM AUTHOR]

Highlights • Calculation of life cycle costs and payback periods of building intervention packages. • Calculation of financial gap between nZEB and cost optimality. • Study covers single and multi-family house buildings for 2 periods and climate zones. • Ranking of intervention packages based on cost effectiveness and energy efficiency. Abstract Nearly zero energy buildings (NZEBs) constitute one of the main pillars of the energy policy of European Union (EU). Greece has recently established a clear definition for NZEB, however the interdependence between cost-optimality and the energy performance of NZEB has not been adequately studied. The present work includes a cost effectiveness analysis among different energy efficiency interventions for the existing residential Greek building stock. To this end, the calculation of the investment as well as the operating and maintenance cost for a wide range of energy efficiency measures were carried out. All calculations were based on the methodology defined in the Directive 2010/31/EU on the energy performance of buildings, while the economic evaluation assumptions were based on the EN 15459-1 standard. The goal is the determination of the most cost effective (cost-optimal) measures that are applicable for two different building types; Single Family House (SFH) buildings and Multi-family House (MFH) apartment blocks, taking into account the period of their construction and the climate zone they belong to. Furthermore, the scope of the paper includes also the assessment of the gap between these measures and the NZEB thresholds. The analysis showed that in various cases and depending on the exact national NZEB definition, NZEBs are located beyond cost optimality. [ABSTRACT FROM AUTHOR]

Abstract In the UK, housing has been identified as a major sector for contributing to the 80% reduction in carbon emissions over the 1990 baseline by 2050, required by the Climate Change Act 2008. However, pre-1919 housing stock is the least energy efficient and consequently poses challenges to meeting this target. Using a mixed methods approach, the current study demonstrates that, in actuality, there is a significant potential for reducing emissions among this sub-sector of housing, and that the major barriers to energy efficiency retrofits concern a lack of funding, the payback period for the investment, disruption to home life and finding a trustworthy and skilled installer. Moreover, this study finds that homeowners are motivated primarily by the desire to improve home comfort and aesthetics along with a reduction in energy bills rather than in reducing carbon emissions. The paper concludes with recommendations for improving the viability of retrofitting pre-1919 homes through enhanced financial resources, policy support and the promotion of social and economic benefits. [ABSTRACT FROM AUTHOR]

The cost-optimal analysis represents a useful tool to stimulate the refurbishment of existing buildings, highlighting the minimal global cost that private or public users have to sustain in order to attain appreciable energy savings in the building life span. The identification of precise interventions on the building-plant system could steer legislators to the emanation of appropriate financial incentives in order to make the refurbishment of existing edifices more attractive. However, the cost-optimal solutions cannot be generalized as they are strongly influenced by the initial conditions and by the climatic context. In this paper, a traditional social housing unit, realized in Italy during the 1970s, largely widespread and strongly energy-consuming, was analysed in two different climatic zones belonging to the Italian territory. Suitable interventions were identified for the reduction of energy requirements for heating, cooling and domestic hot water production. These analyses were carried out by using the same simulation tool for energy and economic performances, highlighting the deviances among the cost-optimal solutions, the n-ZEB target and the minimal interventions for the containment of energy consumptions imposed by the current Italian legislation for buildings subjected to refurbishment. [ABSTRACT FROM AUTHOR]

This paper empirically investigates the influence of building fabric, services and occupant related factors on actual energy use of six case study dwellings, located in three new low energy social housing developments in UK, covering a variety of built forms and construction systems (timber frame, hempcrete, steel-frame). Physical monitoring of indoor environment and window-opening is cross-related with building fabric and systems’ performance, and qualitative data gathered through occupant surveys, review of control interfaces and handover guidance, to understand the causes of the gap between modelled and measured energy use. Actual energy use is found to exceed design expectations by a factor of three, questioning the need for whole-house mechanical ventilation heat recovery (MVHR) systems at measured air permeability rates of 6 m³/(h.m²) against the design target of 3 m³/(h.m²). Lack of proper commissioning of MVHR and heating systems, combined with inadequate user comprehension about their operation and control leads to occupant ‘misuse’ wherein systems are de-activated, thereby negatively affecting indoor air quality. This is confounded by occupant factors related to higher demand temperatures, unexpected opening of windows during winters due to under-performance of MVHR combined with habitual behaviours, and over-use of heating systems to compensate for higher than expected air permeability. [ABSTRACT FROM AUTHOR]

The provision of proper indoor thermal conditions in winter is a requirement for health and comfort that is seriously compromised in Southern European countries by poverty and inadequate housing. According to Eurostat (EU-SILC, 2016), 10.1% of the population in Spain state they are “unable to keep their home adequately warm” in winter, unveiling one of the critical consequences of energy poverty. Although relevant field monitoring assessment have been conducted in other European countries, very little research has been carried out in the context of Spain. In this study we collected winter indoor temperature data, socio-economic, building and heating system characteristics from 112 multi-family dwellings in social housing built in the 40–80s in the North of Spain. The main building determinants of temperature variation were examined and assessed according to the socioeconomic situation through a mediation analysis. The principal findings showed that households living within district heating networks maintained temperatures above 18   °C on a continuous basis, whereas 54% of households living outside these heating networks presented temperatures below this threshold during night periods in bedrooms, while 25% had temperatures below 18   °C during both day-time and night-time occupied periods. Within this 25% of cold homes, 16.4% corresponded to households under the poverty threshold. As the mediation analyses showed, poorer households in the sample were associated with lower temperatures and higher temperature contrast throughout their dwellings for the following reasons: a lower incidence of vulnerable cases within district heating networks, heating restriction behaviours, higher dependency on room-heaters, lack of central heating and more thermally inefficient dwellings. The evidence presented in this paper offers a new framework for comparing the assumptions derived from other contexts to the situation in Spain about the effects of space heating and housing deprivation on thermal conditions, provides a basis for reviewing some possible intervention, and aims to raise social and political awareness further about this issue. [ABSTRACT FROM AUTHOR]

In this paper, an intelligent ensemble machine learning (EML) method - Bagging was developed for thermal perception prediction. Field data was collected in naturally ventilated (NV) and split air-conditioning (SAC) dormitory buildings in hot summer and cold winter (HSCW) area of China during the summer of 2016. The indoor physical measurement and subjective survey were conducted simultaneously during the field study. To determine the merit of the proposed Bagging approach, the performances of Bagging approach were compared against the artificial neural network (ANN) and support vector machine (SVM) regarding conventional statistical indicators, i.e., mean absolute error (MAE), root mean square error (RMSE), coefficient of determination (R 2 ) and Pearson correlation coefficient (r). Several thermal indices, i.e., thermal sensation (TS), effective temperature (ET*), standard effective temperature (SET*) and predicted mean vote (PMV), were adopted to access the occupants’ thermal comfort and evaluate the model prediction. In our case study, the Bagging model's R 2 for TS, PMV, ET* and SET* were 0.4986, 0.9892, 0.9920 and 0.9900, respectively. It shows higher accuracy than SVM and ANN models in thermal perception prediction and outperforms the classical PMV index in TS prediction. Results indicate the proposed Bagging model's prediction performance is reliable and is highly accurate to predict the thermal perception. [ABSTRACT FROM AUTHOR]

In Europe, the final energy demand and greenhouse gas (GHG) emissions of residential and commercial building stocks account for approximately 40% of energy and emissions. A building stock model (BSM) is a method of assessing the energy demand and GHG emissions of building stocks and developing pathways for energy and GHG emission reduction. The most common approach to building stock modeling is to construct archetypes that are taken to representing large segments of the stock. This paper introduces a new method of building stock modeling based on the generation of synthetic building stocks. By drawing on relevant research, the developed methodology uses aggregate national data and combines it with various data sources to generate a disaggregated synthetic building stock. The methodology is implemented and validated for the residential building stock of Switzerland. The results demonstrate that the energy demand and GHG emissions can vary greatly across the stock. These and other indicators vary significantly within common building stock segments that consider only few attributes such as building type and construction period. Furthermore, the results indicate a separation of the stock in terms of GHG emissions between old fossil fuel-heated buildings and new and refurbished buildings that are heated by renewable energy. Generating a disaggregated synthetic building stock allows for a discrete representation of various building states. This enables a more realistic representation of past building stock alterations, such as refurbishment, compared with commonly used archetypes, and not relying on more extensive data sources and being able to accommodate a wide variation of data types. The developed methodology can be extended in numerous manners and lays groundwork for future studies. [ABSTRACT FROM AUTHOR]

This paper provides an analysis of the relationships between dwelling, household and motivation, behaviour and perception characteristics and thermostatic radiator valve (TRV) settings in living rooms ( n  = 187) and bedrooms ( n  = 159) in UK social housing. The work capitalises on primary data from a socio-technical household survey undertaken in Plymouth, UK during 2015, which was coupled with building audit data. The mean reported TRV setpoint temperatures in the living rooms and bedrooms were 23.4 °C and 21.9 °C, implying that occupants prefer cooler conditions in bedrooms. There were systematic variations according to dwelling, household, and motivation, behaviour and perception characteristics. In general, the setpoint temperatures in individual rooms were higher than the whole house thermostat setpoint temperature, implying that there may be a misunderstanding of the role of TRVs in the home heating system. The research could enable social housing providers, the government and commercial organisations to target energy efficiency measures (i.e. thermal upgrades) and social interventions (i.e. behaviour change) at those dwellings and households where their impact may be most beneficial. The results presented could also be used to improve the assumptions of zonal heating behaviour in energy models, which could result in more realistic predictions of the heating demands of social housing. [ABSTRACT FROM AUTHOR]

India is running 11% peak demand as well as short of electrical energy which is the cause of poor grid availability at many sits in India. This motivates the consumer to install their own captive power plant in the building to improve reliability of electricity building. The photovoltaic system cost is rapidly decreasing day by day as well as it is the pollution free source of electricity it is popularity choice of residential consumers. The electronics loads (DC appliances) are increasing in the building. The PV system is also a source of DC power. Therefore, the integration of the DC appliances as well as PV system to the traditional AC distribution system forced to introduce the DC–AC and AC–DC converters at the PV system and appliances. Which decrease the system efficiency, reliability and system capital cost. In this paper, the comparison analysis of the distribution structures (i) Traditional system: AC distribution system with AC compatible appliances (conventional), (ii) Hybrid system: AC distribution system with DC compatible a appliances (high efficient) and (iii) DC system: DC distribution system with DC compatible appliances. The simulation results of this study shows that DC system in the building shows high efficiency and small capital cost as compared to the traditional as well as hybrid system. It is also need small number of AC–DC–sAC conversion stages. [ABSTRACT FROM AUTHOR]

[Display omitted] • Development of two benchmark models for post-world war II residential buildings. • Average energy use intensity per household (archetypes A and B) were 166 and 155 kWh/m2/year. • Models validated with four-year monitoring data on energy consumption. • Households are dominated by senior adults and their occupancy profiles are presented. • Findings on energy needs and use intensity are useful in temperate and continental climates. In the context of the European carbon neutrality targets, building benchmarks are a key issue for the renovation of existing buildings. Although there are various benchmark methods for energy efficiency characterization, their application to the residential sector is still limited. This paper developed two building simulation models for post-world war II houses in Belgium based on data from post-occupancy measurements and field survey campaigns. The study reports the energy characteristics and occupancy profiled of detached single-family houses. An analysis of energy consumption (electricity and natural gas) and a walkthrough survey were conducted between 2016 and 2019. The benchmark model's validity has been further checked against public statistics and verified through model calibration and monthly energy bill comparison. Two reference models representing 633.702 post-WWII single-family houses in Belgium were created and validated. The first archetype has an average energy use intensity of 166 kWh/m2/year and represents detached single-family houses built between 1945 and 1969. The second archetype has an average energy use intensity of 155 kWh/m2/year and represents detached single-family houses built between 1970 and 1990. The paper provides a timely opportunity to evaluate the real performance of post-world war II most common archetypes concerning design assumptions and how building professionals can turn the energy performance gap challenge to their advantage. The findings on energy needs and intensity are useful for creating future renovation scenarios for similar archetypes in Western European countries. [ABSTRACT FROM AUTHOR]

• Analysis of 15-minute sampled residential electricity consumption data of Dubai. • Households are classified using cooling consumption included in electricity bills. • K-Means clustering is used to group households based on their hourly consumption. • Consumption patterns helped to identify occupant behaviours in summer and winter. • Consumption patterns were cross-referenced to building type and occupant profiles. Analyzing residential load profiles and usage patterns is critical to making better decisions for demand-side management initiatives and designing strategies to get more people interested in energy savings. Therefore, analyzing load profiles, it is crucial to know how hourly consumption varies during summers, winters, weekdays, and weekends. In addition, determining the influence of occupancy, dwelling size, and building topologies on consumption is equally important to build predictive models. Therefore, this paper presents detailed research on the electricity consumption and profiles of the residential sector in Dubai based on the dwellings' characteristics and 15-minute resolution smart meter data. The data utilized includes the cooling systems, the number of occupants, and the physical characteristics of a dwelling, such as its typology, sizes, and number of bedrooms. First, using the K-Means clustering method, the authors grouped the households based on their consumption profiles. Second, the consumption patterns of each group of households were identified and organized based on similar consumption profiles over 24 h. Third, the authors applied several classification algorithms to assess the potential of using dwellings and occupants' characteristics to predict the patterns with which each household is associated. The analysis of consumption patterns showed that 43% of households with cooling included in their bills had the global peak demand at midnight during weekdays and weekends in summer. However, the global peak demand for cooling-excluded households occurs from 7:00 to 10:00 pm on weekdays and, in some specific cases, on the weekends, as early as 10:00 am. Finally, the methods used for classification were able to identify key characteristics driving the patterns of electricity demand and were well suited to this predictive modeling context. [ABSTRACT FROM AUTHOR]

• Analyzed residents' thermal demand characteristics under the global climate change. • A new thermal comfort evaluation model of traditional dwellings was established. • The new thermal neutral temperature and comfort range of residents were proposed. • Different measures to improve the old and new types of dwellings were put forward. Global climate change has led to increased differences in the indoor thermal environment of traditional dwellings and residents' thermal adaptability, but quantitative research in this area needs to be updated and improved. In this paper, taking the old and new types of traditional dwellings of Guangfu Ancient City in Hebei province, China as the example, we first investigated the current situation of indoor thermal environment and thermal comfort characteristics of residents by means of subjective questionnaire survey and objective data measurement. The measured data showed that the average indoor temperature of old-type traditional dwellings in winter was far lower than the thermal comfort range of human body, and it was also higher than the relevant standard in summer. Secondly, we established a new thermal comfort evaluation model of traditional dwellings and proposed a new thermal neutral temperature of residents: old-type traditional dwellings (18.1 °C in winter and 27.1 °C in summer), new-type traditional dwellings (19.8 °C in winter and 25.7 °C in summer). Although the measured data showed that the thermal environment quality of the old-type traditional dwellings was poor, the residents had strong thermal adaptability. Finally, we put forward the different living performance improvement strategies of old and new types of traditional dwellings: The old-type traditional dwellings should focus on strengthening the thermal performance of the envelope structure, while the new-type traditional dwellings should solve the problem of low indoor humidity in winter. This research improves the evaluation system of human thermal comfort of dwellings in cold region of China, and provides a good case reference. [ABSTRACT FROM AUTHOR]

This paper evaluates a parametric analysis towards compliance with the nZEB standard, which in Spain is defined by the latest update of the Technical Building Code. This regulation is critically assessed regarding its ability to promote the concept of cost optimization, promote renewable energy sources and minimize primary energy consumption in the residential sector. To this end, a virtual building was defined and multiple designs were evaluated using DesignBuilder software. A set of 170 alternative scenarios was established and parametrically evaluated for five cities representing the five climatic zones of inland Spain (Bilbao, Burgos, Seville, Madrid and Almeria). The results were evaluated focusing on cost-cost effectiveness and primary energy consumption values for the different scenarios, evaluating them in relation to the minimum requirements set by the regulation. The great potential of photovoltaic energy is highlighted, which allows negative values to be obtained for the two Equivalent Uniform Annual Costs due to the cost avoided through self-consumption. This fact makes the optimal designs tend to electrification, specifically through air and ground source heat pumps. It is worth mentioning that the new Code has only established a minimum target for renewable self-consumption in the residential sector, which should be reinforced in future updates. [ABSTRACT FROM AUTHOR]

• Provided a platform to test various residential building control systems. • Used probability of occupancy to determine setback temperature when unoccupied. • Integrated optimizer with adaptive and occupancy control. • Generated dynamic electricity tariff based on wholesale electricity pricing. • Evaluated the peak load shaving potential with dynamic pricing and optimization. Energy consumption in buildings continues to rise with increased deployment of energy-consuming equipment such as Heating, Ventilation, and Air Conditioning (HVAC) amid a growing world economy. Renewable energy is projected to comprise a majority of the future electricity supply, but the intermittent nature of renewables means that consumption must respond to dynamic supply for optimal utilization. This paper proposes a novel HVAC control strategy for residential buildings using the adaptive comfort model, considering occupancy through probability and real-time information, and optimizing the HVAC schedule to reduce cost, maintain thermal comfort, and respond to the dynamic availability of renewable energy while being generalizable to different situations. To validate this approach, the Universal CPS Environment for Federation (UCEF) co-simulation platform is used to connect advanced building controls with the building energy simulation software EnergyPlus. Simulations are performed for a residential building in Sacramento, CA during a typical summer week. Economic impacts, energy consumption, and thermal comfort are analyzed for traditional, adaptive, and occupancy-based control strategies under demand-based, tiered, and fixed electric tariff systems. Simulation results show that occupancy consideration, adaptive thermal comfort, and optimization can reduce cost by 50.1 %, electricity consumption by 52.9 %, and discomfort by 56.2 % compared to traditional fixed setpoints. The ability of the proposed HVAC control strategy to shift energy consumption away from peak times under a demand-based tariff system is qualitatively analyzed and findings suggest that maximum load-shifting on a grid-scale is attained using occupancy consideration with optimized control and demand-based pricing. For individual residential buildings, similar economic benefits can be gained using the less-complex adaptive HVAC control strategy with existing tiered or simple electric tariff systems. [ABSTRACT FROM AUTHOR]

Residential buildings account for significant proportions of energy demand and greenhouse gas emissions. The dwelling and occupants together have a strong impact on the temporal characteristics of energy demand. This paper presents and validates a new stochastic electricity, space heating (SH) and domestic hot water (DHW) model for UK residential buildings, called CREST Heat and Power (CHAP). The open source model is easily adaptable to over 14,000 different building configurations, which represent the UK residential building stock. A validation with empirical data on domestic hot water, gas demand, and internal temperatures demonstrates the accuracy of the new SH and DHW parts of the model. Notwithstanding some uncertainties in extracting the DHW run-off profiles, the energy consumption, water volume, and the dependency on the number of residents are all well considered. The CHAP model produces mean SH, DHW and temperature profiles that are broadly in agreement with the employed field studies. Future work should focus on the consideration of appliances at the heat/power interface, improving the DHW calibration and extending the approach to other national contexts. [ABSTRACT FROM AUTHOR]

In this study, the objective is to redesign a previous concept for a single-family Zero greenhouse gas Emission Building (ZEB). The concept is redesigned based on comparing greenhouse gas (GHG) emission loads and compensation from different design solutions applied in Norwegian single-family ZEB pilot buildings and selected sensitivity studies. The objective is to see if a previously developed ZEB model (2011) can be redesigned to achieve a life cycle energy and material emission balance (ZEB-OM), which previously was not achieved. Five different design parameters are evaluated: area efficiency, embodied emissions in the envelope, insulation thickness, heating systems and different roof forms with respect to the photovoltaic area. Embodied emissions reductions were possible in the ground foundation, from around 1 kg CO 2 /m 2 to 0.6 kg CO 2 /m 2 per year. Both models are able to compensate for all operational emissions. The new model is in addition able to compensate for 60% of embodied emissions, whereas the previous model only could compensate for 5%. The new model does not reach the life cycle energy and material balance. The paper presents and discusses different approaches for achieving the ZEB-OM balance. Further concept model optimization is needed. [ABSTRACT FROM AUTHOR]

This paper evaluates the cost-effectiveness of renovating single-family houses to Passive House level, as compared to maintaining the existing buildings or renovating to building regulation level. The assessment involved life cycle cost analyses, and concerns the Swedish single-family housing stock constructed between 1961 and 1980, which accounts for about a third of Sweden’s two million single-family houses. These houses, now in need of major renovation, are represented in this study by two reference buildings. The results show that Passive House renovations can be cost-effective, but this largely depends on the type of heat generation used in the houses. The most cost-effective individual renovation measure was installing an exhaust air heat pump, and the least cost-effective was installing new windows. In houses using direct electric heating, the Passive House renovation package was the most cost-effective alternative. [ABSTRACT FROM AUTHOR]

There is currently a limited use of timber products in residential development in Australia due to the dominance of heavy materials such as concrete, steel and brick. This dominant use of heavy materials is a reversal of the traditional material choice that was based predominantly on timber products. Technological advances and efficiencies drove the change to heavy materials to use in residential construction. The emerging issue with this reliance on heavy materials is the impact of their use on the environment. The carbon impact and problem of finite resource depletion associated with concrete, steel and bricks need to be addressed due to the increasing pressure from national and international requirements and legislations. The construction industry needs to reduce its negative impact on the environment and the renewable nature of timber presents a material solution to the problem. Timber from sustainably managed forests and plantations can be utilised as lumber or manufactured into engineered products for residential development. This paper examines the benefits of timber used in building envelopes when compared with conventional high-density materials such as brick and concrete when construction is designed with equivalent thermal performance. Multiple case studies were used to demonstrate the reduced life cycle energy and costs, and the time of construction benefits of timber when used as an alternative to heavy materials. Results revealed that Life cycle energy and time of construction showed noticeable differences between timber construction and heavy materials and cost showing marginal differences. [ABSTRACT FROM AUTHOR]

This paper presents the methodological approach and findings of a simulation study of advanced energy conservation, generation and management technologies applied to two case study dwellings in the UK, so as to achieve net zero energy (NZE) target that includes a reduction of net regulated energy (HVAC) to 0 kWh/m 2 per year and energy generation of at least 50 kWh/m 2 per year. The performance of the dwellings are also tested for a change in energy use and risk of summertime overheating in future climates in the short (2030s), medium (2050s) and long term (2080s). The findings indicate that to meet the NZE targets, regulated loads need to reduce by about half (over current Building Regulations) with community (rather than building-level) renewables playing a major role. It is also found that the NZE targets, given current regulations, are not particularly difficult to achieve in design with regard to energy efficiency but are highly expectant with regard to renewable energy. Further, summertime overheating is projected to be a risk for net zero energy dwellings by the 2050s. Despite this the regulated energy use of both dwellings is projected to reduce by 11 kWh/m 2 /yr, accompanied by a small increase in renewable generation (2 kWh/m 2 /yr). [ABSTRACT FROM AUTHOR]

To move to holistic indoor environmental quality (IEQ) assessment methods of residential building performance in Australia, a relevant evidence base on the comfort behaviour and preferences of contemporary households is needed. A lack of information on the environmental conditions, behaviour and preferences relevant to dwellings in Australia’s hot humid climates has been revealed as an area of ongoing policy and research interest. This paper explores the cooling practices of households living in predominantly naturally ventilated dwellings in Darwin, the Northern Territory through a survey of behaviour, preferences and dwelling construction (n = 102) and a 12-month longitudinal thermal comfort study in 20 houses (n = 2535). The results show that these households employ a range of adaptive behaviours in response to warm and hot conditions. The houses were almost always naturally ventilated, with the assistance of ceiling fans for approximately 50% of the time. The limited use of air-conditioning in these houses is more strongly associated with indoor humidity levels than temperature. These patterns of comfort behaviour provide a basis for the enhancement of building simulation models for the performance assessment of dwellings in naturally ventilated mode in hot humid climates in Australia. [ABSTRACT FROM AUTHOR]

Design choices with a unilateral focus on the reduction of operational energy for developing energy-efficient and near-zero energy building practices can increase the impact of the embodied energy, as there is a trade-off between embodied and operational energy. Multi-objective optimization approaches enable exploration of the trade-off problems to find sustainable design strategies, but there has been limited research in applying it to find optimal design solution(s) considering the embodied versus operational energy trade-off. Additionally, integration of this approach into a Building Information Modeling (BIM) for facilitating set up of the building model toward optimization and utilizing the benefits of BIM for sharing information in an interoperable and reusable manner, has been mostly overlooked. To address these issues, this paper presents a framework that supports the making of appropriate design decisions by solving the trade-off problem between embodied and operational energy through the integration of a multi-objective optimization approach with a BIM-driven design process. The applicability of the framework was tested by developing a prototype and using it in a case study of a low energy dwelling in Sweden, which showed the potential for reducing the building’s Life Cycle Energy (LCE) use by accounting for the embodied versus operational energy trade-off to find optimal design solution(s). In general, the results of the case study demonstrated that in a low energy dwelling, depending on the site location, small reductions in operational energy (i.e. 140 GJ) could result in larger increases in embodied energy (i.e. 340 GJ) and the optimization process could yield up to 108 GJ of LCE savings relative to the initial design. This energy saving was equivalent to up to 8 years of the initial design’s operational energy use for the dwelling, excluding household electricity use. [ABSTRACT FROM AUTHOR]

Airtightness testing is widely undertaken to assess the as-built performance of dwellings, in support of achieving energy and ventilation strategies. Mandatory schemes operate in some countries, such as the UK, to ensure that dwellings are built in accordance with their design air permeability. However, testing is only useful if the results give a true picture of the airtightness of the building. Previous literature has investigated factors which could influence airtightness test results but has not questioned data quality, despite the pressure on builders to achieve design targets. This paper presents air permeability results from the largest UK dataset, comprising 144,024 dwellings tested under the Air Tightness Testing and Measurement Association (ATTMA) scheme. The data show an unexpected distribution of test results with narrow peaks just within test targets. Such results were not expected theoretically but do reflect findings in other fields where performance-based targets are in place. Such a close match between design and tested airtightness may be achieved by remedial works taking place during the test rather than afterwards. Recommendations are made with respect to quality assurance systems, design guidance and on-site sealing practices to increase the likelihood of long-term airtight buildings being constructed first time. [ABSTRACT FROM AUTHOR]

During the recent years in Finland, there has been a clear trend that ground source heat pumps are the most widely used main heating source in new detached houses. In addition, other heat pumps have been installed as a supporting heat source and/or to provide cooling. Similar trend cannot be seen in new apartment buildings but heat pumps could be utilized more widely also there. Going towards nearly zero-energy buildings (nZEBs) is a new opportunity for heat pumps. The nZEB concepts often combine passive structural solutions and renewable energy production. This paper analyses life-cycle costs (LCCs) of different heat pump based nZEB concepts for a Finnish new detached house and a new apartment building. The concepts included different heat pumps without and with solar systems. For the apartment building, district heating based concepts were also included as a reference. For both building types, the LCCs were the smallest with the ground source heat pumps (GSHPs) followed by the air-to-water heat pumps. For almost all concepts, the LCCs were bigger for the solar included concepts. The economic order of the solutions did not change when the results were sensitized but the GSHPs were proven to be the most economic alternatives. [ABSTRACT FROM AUTHOR]

Over the last years there have been frequent changes to buildings’ thermal legislation, to cope with increasing environmental restrictions and a wider consumer awareness. This work has a twofold objective: 1 – provide an overall methodology to evaluate changes in buildings’ thermal regulations; 2 – to assess the economic merit of these regulatory changes, which have a profound economic impact especially on homeowners, tenants and the global urban real estate market, but also on the society through wider environmental impacts. The literature has provided several contributions at the scale of buildings, but few at the scale of cities (or even regions). This paper uses the city of Lisbon (Portugal) as a case study to test the methodology and determine the economic impact of the changes made in the thermal legislation by the Government. The economic assessment was made at 3 levels: financial analysis, economic analysis and social-economic analysis. It was found that the new regulation brings not only environmental benefits but also economic benefits in long term at both individual and social level. It was furthermore concluded that the impact of those benefits are geographically uneven, and old areas of the city with worse energy ratings have better economic indicators. [ABSTRACT FROM AUTHOR]

• Self-consumption in residential sector is studied under Spanish regulatory framework. • An average-day model versus a whole-year model is benchmarked. • Scheduling household appliances is analysed in a residential building. • Ex-ante and ex-post renewable energy sharing is investigated. Studies on self-consumption in residential use are constantly evolving, and society claims new solutions in response to changes to new paradigms. This paper aims to optimise the sizing of a self-consumption installation for collective self-consumption in a residential building under the Spanish regulatory framework. The study considers the current price volatility in the retail electricity Spanish market and focuses on the techno-economic analysis of self-consumption in a building consisting of 12 dwellings using photovoltaic energy and the possible support of a storage system. The three aspects analysed are the sizing of the self-consumption facility, the use of smart appliances to shift their consumption to more cost-effective times and the sharing of the renewable energy generated by the facility among the consumers participating in the collective self-consumption. This study employs two models, an average-day model and a whole-year model. The techno-economic analysis yields that between the two self-consumption modalities for residential consumption, the modality with surplus simplified compensation is more profitable than the one without surpluses. Finally, the study focuses on sharing the total renewable energy generated among the participants. The results indicate that both ex-ante and ex-post dynamic sharing brings few benefits. [ABSTRACT FROM AUTHOR]