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This paper presents the building stock model CESAR (Combined Energy Simulation And Retrofitting), which is based on bottom-up modelling methodology for the development of sustainable energy transformation strategies for the buildings in Swiss districts. CESAR is composed of two sub-models: a Demand Model (DM) and a Retrofitting Model (RM). The DM is tasked with identifying the current energy demand of buildings in districts. It builds on geo-referenced information and available census data, and its flexibility allows it to be applicable to any kind of residential neighbourhood within Switzerland. The DM is based on an automated bottom-up modelling technique, which employs the dynamic building energy simulation software tool EnergyPlus as its simulation core to generate hourly energy demand profiles of individual buildings taking the interactions with neighbouring buildings (e.g. shading and solar inter-reflections) into account. Once current energy demands are calculated by the DM, the RM further offers the possibility to apply a set of energy transformation scenarios, based on the Swiss Energy Strategy 2050, to generate future demand and emission projections of districts including key economic indicators. Besides that, the building energy performance under climate change projections can be evaluated. In this paper, the tool is applied on three case study districts, an urban, suburban and rural area, within Switzerland and different transformation scenarios according to the Energy Strategy are investigated. Results revealed significant differences between the two implemented transformation scenarios, the Business as Usual (WWB) and the New Energy Policy (NEP). While in the WWB scenario, only a small number of buildings reaches the intended targets for primary energy and GHG emissions until 2050, the NEP scenario induces a much higher transformation of the districts. Besides that, the significance of the impact of global warming on future cooling demand is shown. [ABSTRACT FROM AUTHOR]

The use of radiant technology in attics aims to reduce the radiation component of heat transfer between the attic floor and roof decks, gables, and eaves. Recently, it has been shown that EnergyPlus underestimates the savings using radiant technologies in attic spaces. The aim of this study is to understand why EnergyPlus underestimates the performance of radiant technologies and provide a solution strategy that works within the current capabilities of EnergyPlus. The analysis uses three attic energy models as a baseline for comparison for EnergyPlus. Potential reasons for the discrepancies between the attic specific energy models and EnergyPlus are isolated and individually tested. A solution strategy is proposed using the Energy Management System (EMS) capabilities within EnergyPlus. This solution strategy produces similar results to the other attic specific energy models. This paper shows that the current capabilities of EnergyPlus are sufficient to simulate radiant technologies in attics. The methodology showcased in this paper serves as a guide for engineers and researchers who would like to predict the performance radiant technology in attics using the whole building energy software, EnergyPlus. [ABSTRACT FROM AUTHOR]

In a traditional building design process (TDP), design variables are fixed sequentially, as opposed to integrated design process (IDP) which tends to avoid sequential design phases to create more sustainable buildings. First, a reference building is introduced and an energy model based on TRNSYS is presented to determine the energy consumption and comfort in the building. The model is validated based on energy bills, certified simulations and literature. Then, the paper performs an extended sensitivity analysis (SA) of 30 design variables with respect to different performance criteria related to energy consumption and comfort, based on a TRNSYS model. Three SA techniques were used, namely standard regression coefficients (SRC), partial rank correlation coefficients (PRCC) and Sobol indices. Results show that all three techniques yielded a similar ranking of the importance of the variables for most model outputs. Interactions between variables were identified with second-order Sobol indices. In the second part of this paper, a traditional design framework was adopted in which sets of variables were fixed sequentially. A SA was performed at each phase of the process, assuming fixed values for parameters chosen in previous design phases. Results show that fixing variables during the phases of a traditional design process tends to reduce the probabilities of finding low-energy consumption designs. Moreover, the influence of some variables was found to change during the design phases. [ABSTRACT FROM AUTHOR]

There has been general recognition within the construction industry that there is a discrepancy between the amount of energy that buildings actually use and what designers considered that they should use. This phenomenon is termed “The Performance Gap” and is normally associated with new buildings. However, existing and older buildings contribute a greater amount of operational carbon. In response to the Performance Gap, CIBSE have developed the TM54 process which is aimed at improving energy estimates at design stage. This paper considers how the TM54 process can also be used to develop energy management procedures for existing buildings. The paper describes an exercise carried out for a university workshop building in which design energy use has been compared with the actual building energy use and standard benchmarks. Moreover, a sensitivity assessment has been carried out using different scenarios based on operation hours of building/equipment, boiler efficiency and impact of climate change. The analysis of these results showed high uncertainty in estimates of energy consumption. If carbon challenges are to be met then improved energy management techniques will require a more systematic approach so that facilities managers can identify energy streams and pinpoint problems, particularly where they have assumed responsibility for existing buildings which often have a legacy of poorly metered fuel consumption. [ABSTRACT FROM AUTHOR]

The German Federal Government put its first net zero office building in operation in 2013 anticipating EU requirements for all public administrations to solely built “nearly zero energy buildings” from 2019 onwards. The two-storey building is situated in Berlin and has been designed for having an overall annual energy demand lower than the in-situ conversion of renewable energies. The paper shows the results of the first year of the operation. The overall annual electric usage is near to the expected value. Nevertheless, intensive monitoring showed differences between the expected and the measured electric usage in the areas of heating and domestic hot water (+172%), ventilation (−36%), lighting (−33%), equipment and auxiliaries (−14% and −13%, respectively), yield of the PV-system (+32%). A numerical model was created to investigate these deviations as well as to evaluate the impact of possible actions aimed at further improving the energy demand of the building. The model was calibrated with measured data, data from surveys, occupancy schedules, and validated by means of different indexes, among which the mean bias error (MBE). The MBE between monitored and simulated energy performance is below ±2% for all stated areas of energy usage. Analogously, the energy needs for cooling, monitored and simulated, as well as the trends of the indoor air temperature in both heating and cooling seasons, are in a very good agreement. In detail, the monthly MBE for the indoor temperature, in specific summer and winter periods and in the considered rooms, is below the threshold of ±5%, with values slightly higher (anyway lower than ±6%) only at the ground floor. Finally, the paper shows that the reasons for the detected deviations in electric energy usage can mainly be related to the usage pattern of the building and to the occupants’ behavior. In order to ensure energy efficiency as high as planned, a suitable monitoring of the energy performance is fundamental. It enables the calibration and validation of tailored energy models to detect possible malfunctions as well as propose actions aimed at further reducing the energy usage of the building. [ABSTRACT FROM AUTHOR]

This paper presents a design and construction of measuring system to measure the power consumption of a split type air conditioning unit and refrigerator in household for energy conservation without having to install any instrument directly to appliances. The system will be only using aggregate power consumption data from only one instrument installed at main power distribution board and using proposed algorithm to disaggregate power consumption data of selected appliances, it is called Non-Intrusive Load Monitoring (NILM). It can significantly reduce cost and time in home energy audit. In this paper authors have used 3 points of monitored data to detect any change of power signal that obtained a 1 Hz sampling rate of active power from energy meter. The proposed method uses basic knowledge about specified air conditioning and refrigerator to establish criteria of disaggregation. Significant saving in air conditioner and refrigerator energy consumption can be achieved by real-time information on their in use. The results showed that the proposed system can disaggregation energy of air conditioner in accuracy 90.71% and refrigerator in accuracy 89.95% from total consumes energy. [ABSTRACT FROM AUTHOR]

Building energy models (BEMs) are typically used for design and code compliance for new buildings and in the renovation of existing buildings to predict energy use. The increasing adoption of BEM as standard practice in the building industry presents an opportunity to extend the use of BEMs into construction, commissioning and operation. In 2009, the authors developed a real-time simulation framework to execute an EnergyPlus model in real time to improve building operation. This paper reports an enhancement of that real-time energy simulation framework. The previous version only works with software tools that implement the custom co-simulation interface of the Building Controls Virtual Test Bed (BCVTB), such as EnergyPlus, Dymola and TRNSYS. The new version uses an open standard interface, the Functional Mockup Interface (FMI), to provide a generic interface to any application that supports the FMI protocol. In addition, the new version utilizes the Simple Measurement and Actuation Profile (sMAP) tool as the data acquisition system to acquire, store and present data. This paper introduces the updated architecture of the real-time simulation framework using FMI and presents proof-of-concept demonstration results which validate the new framework. [ABSTRACT FROM AUTHOR]

Occupants account for a significant impact on building performance through their interactions with zone level building components. Empirically-derived occupant models, despite their potential to represent occupants’ impact in building performance simulation (BPS), have minimal penetration in design and code compliance processes. Instead, occupants are represented with static schedules or simple deterministic triggers. The objective of this paper is to better understand the influence of assumptions made in representing occupant interactions with building components over a BPS model's energy use and comfort predictions, as well as their ability to promote better design decisions. To this end, the energy and daylight performance of a generic perimeter office space in Ottawa, Canada were evaluated using a set of comprehensive performance metrics. Results indicate that representing dynamic occupant–building interactions lead to different energy predictions from the static schedules. The maximum difference in the total electricity use was for window-to-wall area ratios (WWR) of 20%, which was about 30% higher with the stochastic cases than the blind-open static cases. WWR 60% and 40% generally yielded the lowest lighting electricity use with the static and stochastic cases, respectively. This paper emphasizes the importance of incorporating empirically-derived dynamic occupant models for simulation-aided design and code compliance. [ABSTRACT FROM AUTHOR]

This paper represents the first public exhibition of Thermadapt™ building coverings which were invented more than eight years ago. The paper starts with a brief overview of the field of adaptive materials and their applications in various industries. Thermally adaptive building covering sheet fundamentals are explained by laying out the basic structural mechanics of thermally induced gross shape changes in lamina. As a truncated paper, the driving theory, coupon, test chamber and subscale building data could not be included due to length constraints, but will be delivered during oral presentation. Nonetheless, data from outdoor range testing on three independent buildings is presented. These three buildings measuring 1.8m (6 ft) deep x 2.4m (8 ft) wide x 2.1m (7 ft) high showed excellent results. The first was outfitted with Thermadapt™ siding and roofing. The second was outfitted with a variety of different amounts of insulation. The third was used as a control. The configuration of the full-scale test range buildings is shown along with performance data in all midwestern seasons. The data demonstrated that thin thermally adaptive building coverings are as effective as 27 cm (10.5”) of fiberglass insulation, indicating an equivalent R-value of more than 40/cm (100/in). The paper concludes with an overview of the economics of Thermadapt™ building coverings and the intellectual property landscape. [ABSTRACT FROM AUTHOR]

Current trend in the field of civil engineering is building energy-saving and environmentally friendly constructions. One of ways of achieving these trends is using new, progressive construction materials, which are friendly to the environment, have good end-use properties and which are also for reasonable price. Another way is building plant facades and roofs. Plants are capable of regulating temperature and humidity in such constructions. Their advantage is positive influence on healthy living in large cities, where the beneficial properties of plants can be used, like capability of retaining fine dust particles, reducing the level of noise and protecting the structure from weather effects. The paper describes possible connection of both above mentioned modern technologies and gives results of research and development of insulation materials based on natural fibers; in particular technical hemp, flax and jute and their application into buildings with plant facades and roofs. The paper also mentions hydrothermal behavior of the developed materials, including computational simulation of behavior of the optimal hemp fiber based material after building into a structure with plant facade. [ABSTRACT FROM AUTHOR]

Abstract Buildings use approximately 48% of global energy each year in their construction and operation as embodied and operating energy. The embodied energy is used directly through onsite and offsite construction and related processes, and indirectly through the use of materials and equipment. The embodied energy used in a building's construction is called initial embodied energy (IEE), whereas the energy embodied in the recurring processes of maintenance, repair, and replacement is termed recurrent embodied energy (REE). To effectively optimize a building's life cycle embodied energy, both the REE and IEE must be evaluated collectively. However, a building's REE depends on multiple parameters, which can cause significant variations of REE results across studies. A thorough investigation of parameters specific to REE calculation is currently lacking. The REE parameters may introduce significant uncertainties in the life cycle embodied energy calculations. In this paper, we perform a systematic review of literature to identify key parameters affecting REE calculations. We also propose a framework to identify and quantify the uncertainties resulting from these parameters. The findings of this study will help streamline the process of life cycle embodied energy calculation. [ABSTRACT FROM AUTHOR]

Abstract Buildings are responsible for around 50% of energy consumption around the world and most of this because of spaces design, low heat isolation building material, occupant behavior and non-efficient architectural treatments. This have large impact on heating, cooling and ventilation demand, energy consumption of lighting and appliances, and building attitude. This paper aims to focus on passive treatments in Wakala Buildings in Cairo and how far they meet the LEED Criteria which considered the widest spread rating system in the world. By studying wakala in Cairo, there are a lot of passive treatments and energy efficiency that could be found in examples trough surveying and analyzing. Besides the environmental treatments through the natural materials and façade architectural treatments, measuring phase is to declare the efficiency of the wakala through temperature decline between outdoor and indoor. Also, identifying the thermal comfort for occupants indoors. After measuring the wakala buildings, it is the role of applying the criteria of LEED to find out how far wakala meet the LEED rating system criteria. After all, building technologies used in wakala in the field of passive design and energy efficiency would be clear and what is needed for wakala to have a LEED certification. [ABSTRACT FROM AUTHOR]

Highlights • Novel energy flexible building based on smart demand-side management. • Integration of heat pump, latent heat storage and smart demand response. • Smart integration able to operate at optimal times for electricity grid and consumers. • Economic and environmental benefits are achieved. • Energy flexible buildings can have a positive impact on the heating decarbonisation. Abstract One of the greatest challenges for long-term emissions reduction is the decarbonisation of heating and cooling due to the large scale, seasonal variation and distributed nature. Energy flexible buildings with electric heating, smart demand-side management and efficient thermal energy storage are one of the most promising strategies to deploy low-carbon technologies which can benefit the electricity system by reducing the need of reinforcing existing networks and their ability to use electricity in times of low demand and high supply. Combined with spot price contracts, in which the electricity tariff changes every half-hour depending on supply and demand, they can effectively reduce on-peak demand periods, achieve economic profits for end-users and retailers, and reduce the environmental impact of the electricity grid by operating in periods with lower CO 2 emissions rate. To achieve these benefits, it is crucial to develop accurate models for energy flexible buildings as well as control strategies to optimise the complex system operation. This paper proposes a novel flexible energy building concept, based on smart control, high density latent heat storage and smart grids, able to predict the best operational strategy according to the environmental conditions, economic rates and expected occupancy patterns. The smart integration model, carried out in TRNSYS for a Scottish case study, solves a multi-criteria assessment based on future energy demand prediction (learning machine model supported by end-user's predefined occupancy by Internet of Things, present and forecast weather data, and building load monitoring), electricity tariff evolution and building performance. The results show that end-user's electricity bill savings of 20% are obtained and retailer's associated electricity cost is reduced by 25%. In addition, despite an increase in final energy consumption of up to 8%, the environmental impact remains constant due to operation at times with lower CO 2 emissions rate in electricity generation. The developed tools enable the design of smart energy systems for energy flexible buildings which can have a large positive impact on the building sector decarbonisation. [ABSTRACT FROM AUTHOR]

Highlights • A novel framework for the assessment of adaptive facade systems is developed. • Our analysis characterized adaptive facades from the market perspective. • Process mapping of three case studies identified facades' process delivery hurdles. • Currently most adaptive facades are nor designed with a user-centered approach. • Façade sub-contractor & building operator is crucial for long-term performance. Abstract During the last decades, a great number of innovative building envelope materials and façade components have been developed. The majority of these technologies promise significant improvements in energy efficiency and occupant's comfort, with products that are easily available in the market. However, it remains a challenge to assess the performance of such facades, leading to difficulties for efficient design, operation, and maintenance. As a consequence, the market adoption of adaptive facades is not realizing its full potential, resulting in missed opportunities for energy savings and improved occupant satisfaction. In this study, the current trends of adaptive facades are investigated, with particular emphasis on their performance assessment. Based on extensive literature review, the gaps in assessment of adaptive facades are determined and a novel object-based façade characterization and classification framework is proposed. Furthermore, a generic stakeholder map and process map are presented to explain current adaptive façade delivery practices. In addition, the findings of interviews and two focus group discussions with experts and specialists are presented to elucidate their expert opinions, leading to a validated framework of key performance indicators. As results of this paper, the gaps related to adaptive façade systems' assessment are identified with respect to the different actors and stakeholders, and insights and perspectives on current trends and future challenges of adaptive façade system assessment are provided. [ABSTRACT FROM AUTHOR]

Cooling demands of commercial buildings present a relevant challenge for a sustainable future. They account for over half of the overall energy needs for the operation of an average office building in warm climates, and this situation is expected to become more pressing due to increasing temperatures in cities worldwide. To tackle this issue, it is widely agreed that the application of passive strategies should be the first step in the design of energy efficient buildings, only using active equipment if it is truly necessary. Nonetheless, there is still further need for information regarding the potential limits derived from their application. This paper explores the effectiveness of selected passive cooling strategies in commercial buildings from warm climates, defining performance ranges based on the assessment of multiple scenarios and climate contexts. This task was conducted through the statistical analysis of results from documented research experiences, to define overall ranges and boundary conditions; and through software simulation of selected parameters to isolate their impact under a controlled experimental setup. General findings showed that the mere application of passive strategies is not enough to guarantee relevant savings. Their effectiveness was conditioned to both the harshness of a given climate and different building parameters. Specific recommendations were also discussed for the selected passive strategies considered in the evaluation. [ABSTRACT FROM AUTHOR]

Centralized air distribution systems in non-residential buildings are characterized by an extensive air distribution network, that has to be built in a building environment with finite degrees of freedom. The ductwork layout, i.e., the network structure of the ducts, as well as the number and location of the fans, has a large impact on the total cost and performance of the air distribution system. Nevertheless, existing air distribution system design methods are limited to the sizing of each duct (and fan) in the network. The layout itself is considered predetermined, and thus not explicitly taken into account for optimization. In this paper, we meet this shortcoming by presenting the air distribution network design optimization method, that is able to calculate the optimal air distribution system configuration, i.e., the optimal layout and duct and fan sizes, while minimizing the total cost of the air distribution system. A multi-start local search algorithm is developed, consisting of a constructive and a local search phase. In the first phase, multiple air distribution system configurations are generated, and evaluated for feasibility. In the local search phase, all feasible solutions are further optimized in terms of material costs by decreasing and increasing the duct diameters following the steepest descent/mildest ascent approach. An application of the algorithm on a realistic test case demonstrates its usefulness in practice. [ABSTRACT FROM AUTHOR]

Buildings consume a significant amount of energy worldwide in maintaining comfort for occupants. Building energy management systems (BEMS) are employed to ensure that the energy consumed is used efficiently. However these systems often do not adequately perform in minimising energy use. This is due to a number of reasons, including poor configuration or a lack of information such as being able to anticipate changes in weather conditions. We are now at the stage that building behaviour can be simulated, whereby computer programs can be used to predict building conditions, and therefore enable buildings to use energy more efficiently, when integrated with BEMS (i.e. simulation assisted control [1]). In this paper we demonstrate a low cost BEMS that uses building simulation to predict optimised electrical heating startup control points. Those that use electricity for heating in Scotland, where this study was based, tend to be fuel-poor, hence there is a strong case for optimisation, particularly when electricity costs nearly three times as much as the equivalent unit of gas for heating applications. The proposed system demonstrated a 50% energy saving in the reduced heating time compared to scheduling when retrospectively evaluated. [ABSTRACT FROM AUTHOR]

In the US, building sector consumes approximately 41% of all U.S. primary energy and 70% of all generated electricity. Office building uses the largest percentage of primary and derived energy in the commercial buildings sector. Therefore, energy saving is the primary target of building renovation and equipment retrofit. To estimate energy savings after a renovation or equipment retrofit, measurement and verification (M&V) must be conducted based on energy use models or benchmark tools to track and assess savings. Although some methods and modeling tools are applied more often, there is no well-accepted model formulation methodology and some methods have high uncertainty. This paper discusses a method to formulate the energy use model as an inverse regression model via an advanced and robust high-dimensional data analysis method. According to the inverse regression model, independent variables determined to be most influential to the energy consumption should be metered prior to building retrofit or audit. To select the most influential variables, this research considers a comprehensive set of potential key variables to avoid underspecified model issue. The models established by this method are observed to have great power in predicting the building energy consumption. More importantly, through the variable selection procedure, the method identifies key variables that should be monitored to continuously improve the building energy performance. A simulation study and a case study are presented to show the effectiveness of the new approach. [ABSTRACT FROM AUTHOR]

Virtual in-situ sensor calibration (VIC), using Bayesian MCMC with system models, can be applied to large-scale building sensor networks in order to calibrate multiple working sensors including virtual and physical sensors. Using the calibration strategies herein, VIC methods work to overcome various systematic errors (from simple to troublesome) that cannot otherwise be handled by a conventional calibration. Thus, it is important to understand and evaluate the VIC strategies in a whole system with various error conditions to ensure reliable performance of VIC in the operational stage. This study applied individual calibration strategies to a whole building system (a LiBr–H 2 O refrigeration system), and their effectiveness and limitations in solving the VIC problem were evaluated for the calibration of each type of working sensor under the various error conditions that cause negative effects. The combined strategies are also suggested to improve calibration accuracy by overcoming the individual limitations. This paper (1) explains how to formulate the individual and combined VIC strategies with Bayesian MCMC, (2) shows their capability to handle negative effects and limitations, and (3) demonstrates how combined strategies surmount the individual limitations for a high accuracy in various error conditions. [ABSTRACT FROM AUTHOR]

Model-based control schemes such as model predictive control (MPC) can assist smart-energy systems in achieving higher efficiency and utilization of renewable energy sources. A practical barrier for deploying such control schemes for space heating of residential buildings is the costs related to obtaining the weather data measurements needed for identifying a model that describes the dynamic behaviour of the building. Therefore, this paper reports on a simulation-based study investigating whether there is a significant impact on the performance of MPC schemes when substituting these weather measurements with data from meteorological weather services. Since access to weather forecasts is necessary during the operation of the MPC scheme, this implementation approach draws on data already available to remove the need for weather measurements. The results indicated that this approach only led to a minor performance impact in that heating savings were reduced by 4% while comfort violations increased by less than 0.1 Kh per day on average. The results thereby suggest that the use of data from meteorological forecast services for model identification may constitute a cost-efficient alternative to on-site or near-by weather measurements. [ABSTRACT FROM AUTHOR]

Built-up areas tend to comprise a variety of buildings with diverse and complex shapes, functions and construction characteristics. This variety is the source of significant challenges when calculating building energy use at the building stock level. Moreover, the process of developing stock models usually requires large amounts of data that are frequently scarce, nonexistent or at least not publicly available. Under these circumstances, defining a limited set of reference buildings representing the stock is useful to study the actual energy consumption and the potential effects of different energy conservation measures. This paper presents a new method for developing typical residential reference buildings at district level for bottom-up energy modeling purposes. By means of widely and freely available satellite images, an information database of building shapes is created and a clustering analysis of the geometrical features is performed to define a number of archetypes representative of the heating and cooling energy demand of the district. The method is tested and demonstrated through the case study of the Yuzhong District in Chongqing (China) by comparing the Energy Use Intensity (EUI) of the archetypes derived in this way against detailed dynamic simulations. Results show very small differences in the estimated stock energy consumption (+0.03% in heating energy consumption and +2.97% in cooling energy consumption). [ABSTRACT FROM AUTHOR]

Natural ventilation is a green building strategy that improves building energy efficiency, indoor thermal environment, and air quality. However, in practice, it is not always clear when and how to utilize the natural ventilation and coordinate its operation with the HVAC system. This paper introduces a reinforcement learning control strategy, specifically through model-free Q-learning, that makes optimal control decisions for HVAC and window systems to minimize both energy consumption and thermal discomfort. This control system evaluates the outdoor and indoor environments (temperature, humidity, solar radiation, and wind speed) at each time step, and responds with the best control decision that targets both immediate and long-term goals. The reinforcement learning control is evaluated through numerical simulation on a building thermal model and compared with a rule-based heuristic control strategy. Case studies in hot-and-humid Miami and warm-and-mild Los Angeles demonstrated the superior performance of reinforcement learning control, which led to 13% and 23% lower HVAC system energy consumption, 62% and 80% lower discomfort degree hours, and 63% and 77% fewer high humidity hours compared to heuristic control. Unlike heuristic control that requires specific knowledge of individual buildings and the creation of exhaustive decision-making scenarios to improve performance, reinforcement learning control guarantees optimality through self-advancement on given goals and cost functions and is able to adapt to stochastic occupancy and occupant behaviors, which is difficult to accommodate by heuristic control. [ABSTRACT FROM AUTHOR]

The requirements concerning energy performance of buildings and their internal installations, particularly HVAC systems, have been growing continuously in Poland and all over the world. The existing, traditional calculation methods following from the static heat exchange model are frequently not sufficient for a reasonable heating design of a building. Both in Poland and elsewhere in the world, methods and software are employed which allow a detailed simulation of the heating and moisture conditions in a building, and also an analysis of the performance of HVAC systems within a building. However, these systems are usually difficult in use and complex. In addition, the development of a simulation model that is sufficiently adequate to the real building requires considerable time involvement of a designer, is time-consuming and laborious (Menberg et al., 2019) [1]. A simplification of the simulation model of a building renders it possible to reduce the costs of computer simulations. The paper analyses in detail the effect of introducing a number of different variants of the simulation model developed in DesignBuilder on the quality of final results obtained. The objective of this analysis is to find simplifications which allow obtaining simulation results which have an acceptable level of deviations from the detailed model, thus facilitating a quick energy performance analysis of a given building. [ABSTRACT FROM AUTHOR]

The paper contributes to the fulfilment of the environmental targets of the EU by introducing an innovative solution for envelopes of nearly zero-energy buildings (nZEB). It presents the development of an environmentally friendly alternative to aluminium curtain wall systems for new constructions or renovations. The research and development were from the early stages led by design strategies for low embodied energy and embodied carbon structures. The first technical concept was analysed using comparative life cycle assessment (LCA). Prototypes were tested to verify their technical performance (air- and water tightness, fire resistance, acoustic properties, short- and long-term hygrothermal monitoring). The final pre-production design was subjected to a detailed LCA, and various possibilities for its improvement were suggested and assessed. The early-stage LCA showed a high potential for reduction of the embodied environmental impact by utilization of natural materials. The results of the experimental testing proved that thus developed curtain wall system fulfilled the standard technical requirements. The detailed pre-production LCA study proved that the fabrication of one panel of the curtain wall system being developed causes significantly lower environmental impact compared with a panel of a common aluminium curtain wall system. [ABSTRACT FROM AUTHOR]

Urban energy modelling requires a large amount of detailed data to perform systematic dynamic simulations of a large number of buildings, where the adoption of energy efficiency strategies is an important concern for sustainable urban planning. National statistical datasets collect important aggregated data regarding building construction, energy consumption and occupants, and cities are making a significant effort to update spatial referenced data of their territory. However, these data is generally not detailed enough, being available at different scales and in different formats. The integrated use of these data is critical to validate different methods to predict and model energy consumption in cities, as well in addressing its energy saving potential. Furthermore, scenario analysis for retrofit or new design is only possible at building scale, highlighting the potential of a bottom-up database. This paper presents the process of collecting, mapping, cleansing and integrating urban data resulting in an UBD to support an information system for Smart Cities. The goal is to reduce the gap between the available urban data and the specific data required to run a complete urban building energy simulation. Key characteristics of an UBD are explored and applied to a case study in Lisbon, Portugal. As a result, a Buildings Dashboard is developed, materializing the UBD user interface. This dashboard allows the interactive visualization and data exploration of the building stock at multiple scales. Future work includes the development of an Urban Scenario category, bringing new insights on urban energy simulation and scenario evaluation to this platform. [ABSTRACT FROM AUTHOR]

In recent times, numerical simulations are increasingly gaining ground for the energy saving and thermal comfort evaluation of historical buildings. In the present paper a transient 2D model of the Pavilion 2 B of the Ex-Mattatoio (Past abattoir) in Rome is presented, created by Computational Fluid Dynamics (CFD) software based on the finite element method (FEM). The simulations take into account time variations and interactions between indoor and outdoor thermal conditions, with the aim of evaluating different usage profiles and of estimating passive cooling effects in presence of natural ventilation and high thermal masses. The main goal of this work is to show the CFD numerical models potential in quantifying the cooling effects and the indoor thermal comfort conditions, in order to enhance passive and hybrid strategies based on natural ventilation and nocturnal thermal masses precooling. [ABSTRACT FROM AUTHOR]

This paper evaluates the potential heating and cooling energy use and cost savings associated with improved controls of dynamic insulation materials (DIMs) when used in multilayered wall assemblies for commercial office buildings. Using a genetic algorithm (GA) based optimization technique, optimum R-value settings are identified for the DIMs throughout the year. These optimal R-value settings are selected to maximize energy cost savings when compared to traditional static insulated wall systems. It is found that optimal control settings for DIMs depend on several factors including building design and operation strategies as well as climatic conditions. Moreover, the optimal settings were found to depend on the orientation of exterior walls and well as the climatic conditions. Specifically, the analysis results indicate that north-facing walls are more active and frequently have to change their R-value in order to minimize the office building energy use and cost. When optimally controlled, DIMs could save up to 17% of annual heating and cooling energy costs for US office buildings. [ABSTRACT FROM AUTHOR]

Ubiquitous modernization of building energy and management systems brings tendencies for an effective integration of renewables in buildings. This article shows how solar energy can be in charge of energy savings within a building by integration of solar systems with Trombe wall. Numerical calculations of Trombe wall thermal resistance and its performances in comparison with a common wall are considered. Additionally, energy-efficiency gaining by a combination of PV modules and Trombe wall, using simulations by SAM (System Advisor Model) software is discussed. PV module parameters and their impact on its electricity production are observed and analyzed. The PV module parameters, analyzed in the paper are: the tilt angle α of PV modules, incident angle β of direct sunrays on PV modules, normal beam irradiation N and PV cells operating temperature. With bigger incident angle β of direct sunlight on PV modules, the normal beam irradiation is smaller, which brings less electricity production. The impact of PV module operating temperature can be neglected in comparison with the impact of tilt angle on PV module electricity production. The optimal tilt angle of PV modules for generating maximum annual electricity is around latitude angle. It varies with normal beam irradiation to achieve the maximum monthly electricity production. [ABSTRACT FROM AUTHOR]

European Union Directive 2010/31/EU (EPBD Recast) has constituted the cost considerations into the energy performance calculations and put the Member States (MS) under the obligation that by the end of 2020, all new buildings should be designed and constructed as nearly zero energy buildings. On the other hand, reaching nearly zero energy level buildings and ensuring the decrease in carbon emissions may require high-cost measures, such as renewable energy systems. Even though the energy efficiency calculation method proposed by European Commission uses the ‘global cost’, high investment costs may cause a conflict in building construction phases. This paper focuses on the highest possible energy saving for building sector while considering the global costs and market barriers caused by high investment costs and long payback periods. For this purpose, nearly zero energy level definition is suggested to be carried to the district level. It is proposed to analyze nearly zero energy levels firstly in buildings in the settlement and next in the district scale by implementing the further energy efficiency measures, such as the use of district heating/cooling systems and installation of renewable energy technologies in addition to the ones installed on-site. Financial benefits were also analyzed and compared, in terms of investment and global costs of nearly zero energy levels of buildings and districts. [ABSTRACT FROM AUTHOR]

The thermal behaviour of buildings in transient conditions is established by the temperature evolution of the external environment. Determining the thermal evolution of buildings is of crucial importance for building energy design, as well as for energetic performance evaluation. Building energy performance evaluation and calculation of energy use for space heating and cooling can be carried out by several methods of various degrees of complexity and accuracy. These methods are implemented in such simulation codes as NBLSD, Il DOE-II, ENERGY PLUS and others. In order to comply with the Energy Performance of Buildings Directive (EPBD), the studies and research in this field start from the Directive 91/2002/CE and subsequently lead to the EN ISO 13790:2007. The latter proposes a thermal model for a building composed of five resistances and one capacity, called R5C1, and also offers its dynamic solution with a simple hourly computational model. The present paper suggests the solution and dynamic simulation of the R5C1 model and an evaluation of its use in building energy design. Finally, a case study regarding a typical average day in June in Catania (Sicily, Italy) is presented. The implemented model and the relative simulation results have confirmed the advantages of such a solution and have been validated for some modules of the CONPHOEBUS scrl Research Building in Catania. The proposed model has the advantage of a small number of parameters (5 thermal resistances and 1 thermal capacity) and has a simple formulation and then requires low computational resources. Furthermore, this model allows the correct estimation of the user profile with few and not sufficiently precise input data. Due to the above listed properties the proposed model was adopted by the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) for an extensive energy consumption simulation campaign involving 5000 buildings in Italy (a campaign of measurements on 20,000 buildings planned for 2017) for the calculation of statistical consumption data for public buildings. The results ENEA has obtained from our model are in excellent agreement with the statistical data determined by the Italian National Institute of Statistics (ISTAT). [ABSTRACT FROM AUTHOR]

According to the Directive (2010/31/EU), the main goal in the energy performance of buildings, especially for achieving longer-term objectives in the energy saving, is achieving Nearly Zero-Energy Buildings (NZEBs). Thus, this plan can be achieved by refurbishing of existing or by constructing new buildings to satisfy NZEB requirements. Nowadays, refurbishment of existing buildings to satisfy NZEB requirements becomes one of the major aim in construction. In solving this refurbishment problem, Multi-Attribute Decision Making (MADM) methods help here to evaluate existing state of buildings and to compare them with optimal alternative, which equals to NZEB. This comparison allows selecting optimal refurbishment methods to achieve NZEB requirements. However, existing MADM methods do not applied to compare existing alternatives (i.e. buildings) with the optimal alternative (i.e. NZEB), which is based on standards and laws. Usually existing researches present comparison of selected alternatives among each other or with the best alternative from compared, like in the TOPSIS or ARAS methods. Therefore, in this paper, we analyse the concept of a Passive house and NZEB and its applicability in Lithuanian standards and, respectively, define the optimal alternative (i.e. an optimal building). Second, we analyse possibility of extending existing MADM methods to be MADM optimal (MADM-opt). Moreover, we present several modifications how to transform WASPAS, ARAS and TOPSIS by adding optimal alternative. The modified methods were applied for evaluation of 13 apartments. The results show that MADM-opt is useful for the assessment of alternatives and their evaluation according to the optimal alternative. Moreover, it allows determining difference between the assessed alternatives and the optimal alternative. [ABSTRACT FROM AUTHOR]

The built environment is materially inefficient, with structural material wastage in the order of 50% being common. As operational energy consumption in buildings falls, due to continued tightening of regulations and improvements in the efficiency of energy generation and distribution, present inefficiencies in embodied energy use become increasingly significant in the calculation of whole life energy use. The status quo cannot continue if we are to meet carbon emissions reduction targets. We must now tackle embodied energy as vigorously as we have tackled operational energy in buildings in the past. Current design methods are poorly suited to controlling material inefficiency in design, which arises as a risk mitigation strategy against unknown loads and uncertain human responses to these loads. Prescriptive codes are intended to result in buildings capable of providing certain levels of performance. These performance levels are often based on small tests, and the actual performance of individual building designs is rarely fully assessed after construction. A new approach is required to drive the minimisation of embodied energy (lightweighting) through the collection of performance data on both structures and their occupants. This paper uses an industry facing survey to explore for the first time the potential use of performance measurement to create new drivers for lighter and more usable designs. The use of ubiquitous structural, human, and environmental sensing, combined with automated data fusion, data interpretation, and knowledge generation is now required to ensure that future generations of building designs are lightweight, lower-carbon, cheaper, and healthier. [ABSTRACT FROM AUTHOR]

Large-space buildings have large spatial scale, complicated structures and dense people. Roof systems are key parts of their enclosures. The structural systems of large-space buildings need light materials and reasonable stresses while cover soils suggest load increase and structural bearing capacity adaptability change. In this paper, comprehensive adaptability of the overall cover soil of saddle-shaped shell structures and energy efficiency are simulated and evaluated through Sap2000 software and Design Builder software. The findings are that cover soil greening can greatly save energy for buildings of “saddle-shaped” shell structures and structural thicknesses increase linearly with cover soil load increase, the structures are highly adaptive to cover soil, and it is positively significant to combine large space “saddle-shaped” shell structures with cover soil greening. The integration of the relationship among the “saddle-shaped” shell structure, energy-conserving effect, and cover soil load provides further research basis for the practical application of the overall roof greening of “saddle-shaped” shell structure. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2 ) reduction has obtained worldwide attention due to the global warming effects and the mitigating means such as carbon tax. Among the CO 2 emission sources, construction and building related activities consume a considerable amount of energy and produce a significant volume of greenhouse gases (GHGs). This paper proposes an integrated simulation and optimization approach to reducing CO 2 emissions from the on-site construction process, which consists of three main steps: (i) construction process simulation, (ii) CO 2 emission quantification, and (iii) labour allocation optimization. The construction process is simulated utilizing a discrete-event simulation (DES) platform, Simphony.NET, in order to quantify and analyze the amount of CO 2 emissions produced by the construction process. Based on the simulation model, the crew sizes for labour-intensive activities are analyzed and optimized with respect to CO 2 emissions, with a genetic algorithm (GA) employed as the method of optimization. The integrated simulation and optimization approach is capable of reducing CO 2 emission through (i) the choice of the start-date of the construction, and (ii) labour allocation optimization. A case study in Edmonton, Canada, is used to demonstrate the effectiveness and applicability of the developed approach. Results indicate that the total measured CO 2 emissions from on-site construction can be reduced by 21.7% in winter by optimizing labour allocation. This research thus proposes a generic methodology by which to measure and reduce CO 2 emissions produced from construction process through labour allocation. [ABSTRACT FROM AUTHOR]

The paper shows boundary conditions, conceptions, design criteria and expected energy performance of a new net zero-energy building, designed for a typical Mediterranean climate and presently under construction in a middle-size city of South Italy. The single-storey building is the final outcome of an Italian project – SMARTCASE – promoted under the umbrella of the European Regional Development Fund. The building has been designed for being a best practice of a new way of living, by reducing - as much as possible - energy needs, energy demand of active energy systems and by converting the entire request by means of on-site renewables. Starting from the architectural concept, and thus shape, geometry and organization of the functions, as well as by considering the thermo-physical peculiarities of the thermal envelope – built in coated X-lam in order to allow both thermal resistance and thermal capacity - the conception phase has interested many professionals. Analogously, all active energy systems, and thus the heating, ventilating and air-conditioning devices, equipment for domestic hot water, artificial lighting and plugged powers are the top of the technology. In addition, a great effort has been dedicated to monitoring and controls. Moreover, the solar energy systems, the air-cooled heat pumps, the geothermal boreholes allow to close to zero the energy balance. [ABSTRACT FROM AUTHOR]

A segmented dynamic dwelling stock model is proven useful for understanding the development and changes of ageing building stocks, which is highly relevant for renovation measures and estimates of energy use and emissions in aggregated building stocks. In this paper, such a model is developed further for detailed analyses of dwelling stock energy demand and exemplified for the Norwegian dwelling stock 1960–2015. The dwelling stock model simulates the development in stock size and composition and is combined with archetype-specific energy intensities to estimate the total energy demand. After calibrating the model results with statistics, the model is used to explore the phenomena and causes of historical changes. A large-scale improvement of the energy efficiency of the Norwegian dwelling stock has taken place through renovation and construction of new dwellings. A historical shift to more efficient energy carriers and heating systems has had an effect on energy savings in the system, of the same size as the effect of the improved energy efficiency of the stock. However, the total average energy savings per m 2 are offset by changes in user heating habits. A significant decrease in average delivered energy intensity per m 2 is only observed after the introduction of heat pumps. [ABSTRACT FROM AUTHOR]

Cost optimization is one of the key elements of the EU regulatory framework concerning the energy performance of buildings. From this economic point of view, the optimum occurs when the global cost over the lifecycle of a building is minimized, and the cost-optimal energy performance level is that related to the minimum global cost. To determine this cost-optimal level by evaluating a great number of design alternatives, it is necessary to exploit automated optimization search procedures. The work presented here concerns the application of cost-optimal methodology, as defined by European regulation, to a low-consumption single-family house in France. The calculation is performed through an iterative input-output process in a computing environment that combines TRNSYS®, transient system simulation tool, with GenOpt®, generic optimization program. The methodology that was adopted allowed around ten thousand building configurations to be simulated in a reasonable computational time. The paper focuses on how the energy system affects the technical and economic optimal design solutions of the building in two different French climate conditions. [ABSTRACT FROM AUTHOR]

This paper presents a systematic, socio-technical and empirical evaluation of the actual energy and environmental performance of a sustainably-designed institutional building (Southeast England), intended to be a teaching tool and ‘living laboratory’ of sustainability. Despite the building being designed to high sustainability standards (Energy Performance Certificate rating of A, low reliance on fossil fuels, natural ventilation and rainwater harvesting) and also being under-utilised during the in-use stage (lower hours of occupation and number of occupants), its actual energy-related carbon dioxide-equivalent emissions are four times more than predicted. This is due to poor energy management of the building, underperformance of the biomass boiler and wasteful energy practices in terms of excessive winter overheating in the atrium, inappropriate lighting controls, and electrical equipment being left on standby. Due to lack of training and understanding of the energy manager, the building management system was not used adequately and issues with installation, commissioning and maintenance of the biomass boiler led to its disuse; however the photovoltaic system generated electricity as expected. Findings from the study show how a mixed-methods approach of building performance evaluation (BPE) should be embedded as part of the build process, to ensure that performance outcomes are met in reality. [ABSTRACT FROM AUTHOR]

This paper is a full review on the development of solar photovoltaic technology for building integration and design. It highlights the classification of Solar PV cell and BIPV product for building design purpose. BIPV poses an opportunity to play an essential part in a new era of distributed power generation. Building integrated photovoltaic systems is powerful and versatile tool for achieving the ever increasing demand for zero energy building of the coming years. While some critical policy challenges exist, the value of generating power directly where it is used, aesthetic designs and flexible thin film module form factors is just starting to be understood, which may help to mitigate the barriers posed for current BIPV applications. [ABSTRACT FROM AUTHOR]

Assessment of the embodied energy associated with the production and transportation of materials during the design phase of building provides great potential to profoundly affect the building’s energy use and sustainability performance. While Building Information Modeling (BIM) gives opportunities to incorporate sustainability performance indicators in the building design process, it lacks interoperability with the conventional Life Cycle Assessment (LCA) tools used to analyse the environmental footprints of materials in building design. Additionally, many LCA tools use databases based on industry-average values and thus cannot account for differences in the embodied impacts of specific materials from individual suppliers. To address these issues, this paper presents a framework that supports design decisions and enables assessment of the embodied energy associated with building materials supply chain based on suppliers’ Environmental Product Declarations (EPDs). The framework also integrates Extract Transform Load (ETL) technology into the BIM to ensure BIM-LCA interoperability, enabling an automated or semi-automated assessment process. The applicability of the framework is tested by developing a prototype and using it in a case study, which shows that a building’s energy use and carbon footprint can be significantly reduced during the design phase by accounting the impact of individual material in the supply chain. [ABSTRACT FROM AUTHOR]

• New building development projects underperform often. • Underperformance leads to increased energy consumption and CO 2 emissions in building operation. • The paper links building project development and building operational performance. • Two simulation methods are combined in a multi methodology framework in the paper. • The paper explores the implications of project partner collaboration for operational building performance in the case of a recent building project. The "performance gap" in the United Kingdom construction industry is a persistent problem as new building development projects underperform more often than not. The "performance gap" is partially attributed to the number of stages involved in building project development and the coordination difficulties of partners with different incentives. The project outcome is important for energy consumption, carbon emissions and occupant well-being. Thus, it is important to study the project management process in terms of the standard time, cost and quality parameters, but also in terms of project partner incentives and coordination, and the subsequent energy performance and resultant indoor environmental conditions. A system dynamics model of project management processes is developed to explore the implications of partner coordination for building quality. The system dynamics model is coupled to a building performance simulation model to explore building energy consumption and Indoor Environmental Quality, and apply this on a recent building project case study. Results show that greater project partner alignment can reduce annual energy consumption up to 12% and CO 2 emissions up to 37%, with greater emphasis in the design stage of the project subject to resource availability. The trade-offs involved on value appropriation are considered and discussion of results points to possible ways for improvement. [ABSTRACT FROM AUTHOR]

• A new methodology to investigate the impact of thermal mass is defined. • The use of unrepresentative boundary conditions could lead to inaccurate conclusions. • High thermal mass helps to decrease and regulate the internal temperature. • High thermal mass could increase energy use in the summer and winter seasons. • Isolating thermal mass through internal insulation results in better energy performance than external insulation. Contradictory conclusions have been reported on whether thermal mass reduces or increases energy demand in hot and cold climates. A novel approach to measuring the impact of thermal mass on the building's energy consumption is presented. The method aims to better represent reality and applies two different control conditions simultaneously in a numerical model: the first condition, which has been used in past studies, adjusts the internal boundary condition based on the time duration of heating/cooling activation (simulating an occupancy pattern) and the second, which has not been used in past studies, adjusts the internal boundary condition based on both the time duration and the internal temperature (simulating an occupancy pattern and the thermostatic control system). When investigating the impact of thermal mass on the internal temperature in a scenario where no heat is transferred into the building, the high thermal mass outperforms the low thermal mass, showing a time-shifting effect, long time lag, and small decrement factor. However, when modelled using the method presented in this paper, high thermal mass results in greater energy consumption during summer and winter periods in Saudi Arabia. During transition seasons where temperature swings occur on either side of the indoor set-point temperatures, thermal mass reduces thermal transmission. The impact of thermal mass is also investigated for several climatic conditions in Saudi Arabia. Simulation results show that an internally exposed thermal massive wall section results in greater energy consumption when compared to a similar building with isolated thermal mass (i.e. insulated internally). This is due to the fact that even though the internal temperature inside the building is being cooled/warmed up to the set-point, the thermal mass continues to transfer heat that is absorbed by the building's fabric from/to the interior, placing a greater demand on the cooling/heating system. Over the course of a year, however, the impact of thermal mass is negligible when compared to other factors, such as the insulative properties of the building's fabric. [ABSTRACT FROM AUTHOR]

The contribution of daylight to energy efficient building design and to the creation of a pleasant environment that provides visual comfort to its users has been a subject of study for years. This paper addresses the way in which daylight can be efficiently used in a typical classroom in Athens, Greece, by improving its distribution in the space and providing shade. Based on the conclusions drawn from the literature review, the system that is chosen for study consists of a light shelf (for shading and light redirection) and semi-transparent movable external blinds (for more shading, adjusted to the occupants’ needs), which are mounted on the glazing of a south-facing classroom. The experimental study consists of six stages, all performed in Radiance software. The individual results and conclusions lead to the definition of the optimum characteristics of the system, including the light shelf's width, mounting height, inclination and reflection index, which upgrade the daylight performance in the space under study. [ABSTRACT FROM AUTHOR]

Occupant behavior is one of the major factors influencing building energy consumption and contributing to uncertainty in building energy use prediction and simulation. Currently the understanding of occupant behavior is insufficient both in building design, operation and retrofit, leading to incorrect simplifications in modeling and analysis. This paper introduced the most recent advances and current obstacles in modeling occupant behavior and quantifying its impact on building energy use. The major themes include advancements in data collection techniques, analytical and modeling methods, and simulation applications which provide insights into behavior energy savings potential and impact. There has been growing research and applications in this field, but significant challenges and opportunities still lie ahead. [ABSTRACT FROM AUTHOR]

The significance of global warming is shaping building procurement, with much of the effort aimed at reducing greenhouse gas emissions through a preferential bidding mechanism. However, only a limited number of studies have quantitatively estimated the potential impact of bid preference on the emission reduction from building construction. The aim of this paper is to improve our understanding of how bid discounts change owners' procurement costs and the magnitudes of emission mitigation. A two-stage optimization model is designed to help the owner determine the discount rate that would automatically control the emission of the awarded contract within a desired level. The goal is for bidders to regard emission reduction efforts as an investment, with returns coming in the form of an increased chance of winning the bid. Our results imply that for the building retrofit project studied herein, a discount rate of 0.6 is suggested for every percentage of emission reduction. This discount level reduces greenhouse gas emissions by 28.2% while raising procurement costs by 3.7% relative to a non-preference mechanism. The increased procurement costs can be partially compensated under existing cap-and-trade scheme. The results show that the choice of discount significantly alters bidders' efforts on emission mitigation, and emission control cost can be minimized with the proposed optimization algorithm. [ABSTRACT FROM AUTHOR]

From the perspective of construction companies, this paper investigates the existence and significance of barriers and driving forces for the implementation of energy-efficient houses in Sweden. Here, eleven construction companies that build low-energy buildings comparable in performance with passive houses have been interviewed. One conclusion is that there is not one specific barrier that keeps energy-efficient housing from taking off. Instead, the barriers include a whole range of issues that have to be considered. Internal pressure has been a strong contributor to the onset of passive house constructions within the companies and the results indicate that personal commitment is central and perhaps the strongest driver. A general reflection from the interviews is that there is a need to show both construction companies and potential customers that it is possible to build passive houses and that they exist. Unlike the national building regulations, which are not considered to be relevant when it comes to energy consumption, the future building regulations from the European Union are identified as a regulatory driver. Moreover, life-cycle thinking is reported to increase among actors, but that it would be beneficial if banks as well as real estate agents could develop a comprehensive view and become better at considering energy and LCC in their capital budgeting templates. Even if the interest for passive houses is considered low among the public, the market is identified as promising among the construction companies - recently actually large enough to become a driver in itself. [ABSTRACT FROM AUTHOR]

An approximate analysis is presented for multi-story setback buildings subjected to strong ground motions. Setback buildings with mass and stiffness discontinuities are common in modern architecture and quite often they are asymmetric in plan. Such buildings are classified by Eurocode 8 (EC8-2004) and codes from other countries as irregular structures, which specify a full 3-dimensional dynamic analysis. There are no recommendations of how the practicing engineer can assess the fundamental frequency by a simple formula or methodology and there are no provisions which allow the structural detailing by a pseudo-static design against an equivalent lateral load. Therefore, an approximate analysis which provides basic dynamic data (frequencies and peak values of base resultant forces) of setback buildings and furthermore an overview of their response during a ground excitation is a useful tool at the preliminary stage of a practical design. This methodology is based on Southwell's formula and the concept of the equivalent single story system. This has been introduced by the authors in earlier papers for assessing the response of uniform along the height of buildings. At present, the accuracy of this procedure is examined in asymmetric tall buildings with a mass or stiffness irregularity. As basic data of the dynamic response of elastic multi-story building systems can be derived by analyzing simple (equivalent) single story systems, a structural layout of minimum elastic torsional response can easily be constructed. The behavior of such structural configurations, which is basically translational in the elastic phase, is also examined in the post elastic phase when the strength assignment of the various bents is stiffness proportional. [ABSTRACT FROM AUTHOR]

The current set of building sustainability rating tools developed for application to new building designs focus mainly on technical aspects. Sustainable building developments are usually assessed by use of building performance indicators, i.e. energy consumption, use of materials and other key features of the buildings reflecting comfort and satisfaction. Such sustainability rating tools recently applied mainly for new building designs, however there is a need to assess the sustainability of measures applied in refurbishment projects. In this case the question of economic feasibility of applied measures appears. Measures differ by sustainability rating and by demand of investment cost for their integration in building design. The paper presents the new approach that let to assess the sustainability and economic utility of refurbishment measures. The proposed approach for eco-efficiency analysis based on application of sustainability rating tools (BREEAM and LEED), cost analysis and MCDA methods. The application of proposed approach illustrated on case study that presents the eco-efficiency analysis of refurbishment measures applied in multi-family apartment blocks. [ABSTRACT FROM AUTHOR]