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To fulfil the hunger for sustainable development, Australian construction sector seems to contemplate toward green design. Green-Star environmental rating system, one of the active building rating systems in Australia, has also been employed in New Zealand, and South Africa. To help engineers and designers obtain comprehensive visualisation on sustainable projects, this paper develops a model to evaluate energy consumption and greenhouse-gas emissions based on typical Australian commercial building alternatives. From that, this paper explains how to achieve points for “Energy” and “Life-cycle impacts” categories of this rating system. The model uses GaBi 8.1 platforms and shows relationships between building's energy consumption, and greenhouse-gas emissions released during the building lifetime. This paper provides insight into life-cycle greenhouse-gas emissions assessment for several typical commercial building fabrics in Australia. The developed model can also be conveniently modified to automate calculations for other credits under the Green-Star environmental rating system, and other environmental rating systems around the world. The study suggests that designers should consider the inverse relationship between building envelopes' total R-value with energy consumption and greenhouse-gas emissions. Another finding shows that materials used for building envelopes play a significant role to manage energy consumption as well as greenhouse-gas emissions amount during the building's life-cycle. [ABSTRACT FROM AUTHOR]

Buildings are responsible for 40% of global energy use and contribute towards 30% of the total CO 2 emissions. The drive to reduce energy consumption and associated greenhouse gas emissions from buildings has acted as a catalyst in the increasing installation of meters and sensors for monitoring energy use and indoor environmental conditions in buildings. This paper reviews the state-of-the-art in building energy metering and environmental monitoring, including their social, economic, environmental and legislative drivers. The integration of meters and sensors with existing building energy management systems (BEMS) is critically appraised, especially with regard to communication technologies and protocols such as ModBus, M-Bus, Ethernet, Cellular, ZigBee, WiFi and BACnet. Findings suggest that energy metering is covered in existing policies and regulations in only a handful of countries. Most of the legislations and policies on energy metering in Europe are in response to the Energy Performance of Buildings Directive (EPBD), 2002/91/EC. However, recent developments in policy are pointing towards more stringent metering requirements in future, moving away from voluntary to mandatory compliance. With regards to metering equipment, significant developments have been made in the recent past on miniaturisation, accuracy, robustness, data storage, ability to connect using multiple communication protocols, and the integration with BEMS and the Cloud – resulting in a range of available solutions, selection of which can be challenging. Developments in communication technologies, in particular in low-power wireless such as ZigBee and Bluetooth LE (BLE), are enabling cost-effective machine to machine (M2M) and internet of things (IoT) implementation of sensor networks. Privacy and data protection, however, remain a concern for data aggregators and end-users. The standardization of network protocols and device functionalities remains an active area of research and development, especially due to the prevalence of many protocols in the BEMS industry. Available solutions often lack interoperability between hardware and software systems, resulting in vendor lock-in. The paper provides a comprehensive understanding of available technologies for energy metering and environmental monitoring; their drivers, advantages and limitations; factors affecting their selection and future directions of research and development – for use a reference, as well as for generating further interest in this expanding research area. [ABSTRACT FROM AUTHOR]

The emergence of climate change and energy security as increasingly important issues has amplified the need for energy policies that manage these issues. While policy-makers adopt energy policies that address climate change and energy security, these policies often include broad strategy statements and may not include specific implementation plans. Accordingly, effectiveness of these energy policies is also evaluated at the strategic level, which may not appropriately evaluate the policies beyond how the policy met its strategic goal(s). This paper assesses the feasibility of mapping energy policies to their strategic, tactical, and operational (STO) levels through two case studies. The first case study assesses the European Union (EU) 2020 energy and climate policy known as EU 20-20-20 as well as the United States’ Executive Orders 13514 and 13423 that mandate energy and greenhouse gas reductions for federal buildings. Results of this paper illuminate potential advantages and limitations of using STO as an energy policy assessment tool and the mapping effort described in this paper suggests that strategic, tactical and operational levels should be addressed explicitly in future energy policies. [ABSTRACT FROM AUTHOR]

Buildings are responsible for more than 40% of global energy usage and as much as 33% of global greenhouse gas emissions in both developed and developing countries. However, the study of carbon emissions over a building's life cycle based on Ecotect and building information modeling in developing areas of Nanjing has yet to be conducted. Therefore, the results and recommendations of this paper represent a contribution to the literature on this topic. The scientific value of this paper is that Ecotect and building information modeling can be helpful in simplifying the estimation of carbon emissions over a building's life cycle because they can provide a majority of the information and calculation tools necessary for performing an life cycle assessment (LCA), which may alleviate the problem of insufficient information when executing an LCA of a building. A sensitivity analysis was performed by changing several parameters to identify the parameters that have the largest impacts on the performance a building. A comparison of the life cycle carbon emissions for each stage showed that the operational stage is the largest contributor to carbon emissions. Approximately 85.4% of the total carbon emissions were generated during operation. The construction stage accounted for 12.6% of the total carbon emissions. Approximately 2% of the total carbon emissions occurred during the demolition stage. Compared to the total carbon emissions over the entire life cycle of the building, carbon sequestration by vegetation was minimal. Thus, these findings indicate that governments can achieve the greatest reductions in carbon emissions by targeting the operational phase of buildings. However, the opportunity for addressing non-operational phases should not be ignored because the average carbon emissions per working area per year of non-operational stages are far greater than those of the use phase. [ABSTRACT FROM AUTHOR]

Growing demand for urban built spaces has resulted in unprecedented exponential rise in production and consumption of building materials in construction. Production of materials requires significant energy and contributes to pollution and green house gas (GHG) emissions. Efforts aimed at reducing energy consumption and pollution involved with the production of materials fundamentally requires their quantification. Embodied energy (EE) of building materials comprises the total energy expenditure involved in the material production including all upstream processes such as raw material extraction and transportation. The current paper deals with EE of a few common building materials consumed in bulk in Indian construction industry. These values have been assessed based on actual industrial survey data. Current studies on EE of building materials lack agreement primarily with regard to method of assessment and energy supply assumptions (whether expressed in terms of end use energy or primary energy). The current paper examines the suitability of two basic methods; process analysis and input–output method and identifies process analysis as appropriate for EE assessment in the Indian context. A comparison of EE values of building materials in terms of the two energy supply assumptions has also been carried out to investigate the associated discrepancy. The results revealed significant difference in EE of materials whose production involves significant electrical energy expenditure relative to thermal energy use. [ABSTRACT FROM AUTHOR]

• The data requirements of quota methods are summarized, and a city-scale database containing 670 credible government office buildings is established. • By comparing the processes, the results and applicability, the selection basis of quota methods under different conditions is refined. • A flow chart of the formulation process and method selection of city-level building energy consumption quotas is constructed. • It is proposed that special attention should be paid to the outliers, and the characteristics of outliers in Chongqing are summarized. Energy consumption quota policies are effective management measures to promote energy conservation and emission reduction in China. Cities need to choose an appropriate method to formulate local energy consumption quota standards. This paper is based on the data of 670 government office buildings in Chongqing and the selected quantile method (QM), quota-level method (QLM) and multiple linear regression (MLR) method, which are widely used in the formulation of city-level energy quotas. By comparing their interpretability, evaluation, consistency and stability, the application conditions and applicability of each method are summarized. MLR has the strongest explanatory power but the highest requirements for the technology and information dimensions. The QLM is more explanatory and stable than the QM and is more suitable for the initial stage of energy quota management. When using the QLM, we should consider scientific classifications and reasonable quota levels. Special attention should be given to "outliers" with abnormal evaluations of the quota results. The outliers in Chongqing are characterized as buildings that have been used for more than 10 years and have an area of less than 5000 m2. Finally, this paper constructed a flow chart of the formulation process and method selection to help policymakers better understand how to choose the most appropriate method and identify inefficient buildings. [ABSTRACT FROM AUTHOR]

Highlights • Overview of US Federal Energy Management (FEMP) lighting efficiency program. • Estimated total benefits of the 2017 lighting update from $33 to 217 million USD. • Estimated energy savings 0.33–4.76 TWh for this update. • Total benefits methodology with monetized full fuel cycle greenhouse gas emissions. • Presents the FEMP lighting categorization structure. Abstract Lighting consumes a great deal of electrical energy in buildings, and the U.S. federal government is the largest single energy consumer in the United States. Therefore, the way that the U.S. federal government manages its lighting energy use is of great importance. One important way that energy use is managed is through Federal Energy Management Program (FEMP) energy efficiency requirements. However, there is not much literature on how these requirements are set and how to value the resulting savings. This paper documents the methodology used to develop these for the 2017 FEMP lighting update. A methodology for calculating the total benefits is presented that goes beyond site energy saved, and includes full fuel cycle energy savings, energy cost savings, emissions offset and monetized emissions costs. The results show total benefits of $33 million USD including 475 kilotons of carbon dioxide (CO 2) offset under the low compliance scenario, $104 million USD including 1494 kilotons of CO 2 offset under the medium compliance scenario, and $217 million USD including 3124 kilotons of CO 2 offset under the high compliance scenario. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon emissions are explored in China's building operations from provincial perspective. • GDIM is employed to factorize ten affecting factors of CO 2 emissions in building sub-sectors. • CO 2 emissions of building sub-sectors are predicted with dynamic simulation. • The contribution of provinces to the change and peak of national emissions are discussed. Carbon emissions from building operations have a critical impact on achieving carbon peaking goal in China. However, the provincial emission performance in building operations are quite different and it is still unidentified how they affect the national emission change and peaking target, making national emission reduction target hard to implement at the provincial level. This paper explores the driving factors leading to emission changes and examines the prospective emission peaks in China and China's provinces by adopting generalized Divisia index method (GDIM) and the combination of scenario analysis and Monte Carlo simulation. Furthermore, the regional emission heterogeneity and the contribution of provinces to the change and peak of national emissions are discussed to identify regions and provinces that should be focused on emission monitoring. Results show that in China and most Chinese provinces, energy consumption of commercial buildings, energy consumption and floor space of urban residential buildings besides income improvement, and the per capita CO 2 emissions of rural residential buildings contributed greatly to emission growth. Under current policies, commercial and urban residential buildings in most provinces would fail to reach their emission peaks ahead of schedule. The urban residential buildings in the northern region, commercial and rural residential buildings in the eastern region caused higher CO 2 emissions. At the provincial level, Shandong, Shanxi and Hebei made the top contribution to total emissions of commercial, urban residential and rural residential buildings, respectively. Shandong and the provinces in north China of urban residential buildings and four provinces including Shandong, Guangdong, Hebei and Zhejiang of commercial and rural residential buildings had the significant impact on the uncertainty of the peaking time of CO 2 emissions. These findings provide a strong decision-making reference for Chinese government to formulate targeted regional emission reduction policies in building operations. [ABSTRACT FROM AUTHOR]

This study investigates an energy-inefficient council housing tower block in London, due for retrofit, by exploring the correlations between occupancy and energy consumption patterns, thermal comfort and building energy performance in the winter. The aim of this study is to evaluate the building performance and develop a reliable building simulation model to be employed in the second phase of the study for developing an energy-efficient and cost-effective retrofit strategy to support the council's plans. The research seeks to demonstrate the significance of using dominant occupancy and energy use profiles as opposed to relying on standardised profiles when calculating building energy consumption using building simulation software. The paper reports on the results from the first phase of the study where a quantitative methodology; including a questionnaire, structured interviews, indoor monitoring, and building simulation modelling was adopted. The results provide evidence that occupants’ socio-demographic characteristics have a considerable impact on household energy consumption and fuel bills. The results also show that indoor environmental issues experienced in many flats are partly attributed to the thermally inefficient building envelope and partly due to occupants’ patterns of operating their homes with evidence of excessive heating energy use in attempts to alleviate the indoor issues experienced. [ABSTRACT FROM AUTHOR]

In this paper, the energy performance of an energy self-sufficient residential building, located in the outskirt of L’Aquila city, in central Italy, is presented. The aim of this study is to demonstrate that even a self- sufficient building, that represents a still uncommon construction in the Mediterranean area, can have optimization margins. The analysis is performed via calibrated model carried out with EnergyPlus™ engine coupled with DesignBuilder. The results of this study show a substantial discrepancy between the high efficiency of the envelope, and the poor performance of the heating system. Therefore, five possible scenarios, that differ for the technological plant, were hypothesized. Based on the total thermal energy consumption of the heating system as it is, equal to 29.9 kWh/m 2  y, the proposed multi-scenario analysis allows to identify a solution that ensures energy savings up to 67.1%. In this study, these results indicate that a proper a priori study of building’s thermal load by considering different plant typologies could help to choose the better solutions for realizing efficient buildings. [ABSTRACT FROM AUTHOR]

Choosing an effective and efficient building design option for energy management as well as for reducing greenhouse-gas (GHG) emissions associated with a building life-cycle is always highly challenging to any designers in the battle to tackle global climate change issues. Researchers around the world are thriving in building optimization models for developing strategies that would result in an overall reduction of a building's energy consumption aside from decreasing GHG emissions. Despite using similar input data sources, challenges to get similar results which are simulated from different software to assess environmental and financial aspects in a life-cycle of a system are still the dilemma to all sustainable development designers. Another difficulty, which happens in the progress of sustainable development in Australia, is that designers may have to follow a variety of green building rating tools to minimize environmental footprint and to increase the efficiency of buildings operation during their lifetime. Time will be consumed if design options are not appropriately and automatically calculated and assessed. In order to obtain building's life-cycle assessment (LCA) along with to achieve Green Star's certificate, choosing an appropriate program to calculate life-cycle energy consumption, life-cycle cost and life-cycle GHG emissions are a necessity to designers. This paper presents a comprehensive review of all considerable researches focus on the biologically inspired algorithms to different fields of sustainable building designs and their module modelling development in recent years (up to 2016). Major fields are reviewed in detail, including building envelope design, comprehensive optimization of several areas simultaneously as well as configuration and control of building energy consumption. The outcomes of this study can assist researchers to choose which program is the best suitable for their study on sustainable assessment. In Australia, based on these design, practitioners can decide the optimum option for their project which can achieve their sustainability goals as well as can be granted the Green Star's certificate less sophisticated. [ABSTRACT FROM AUTHOR]

The importance of embodied energy and embodied greenhouse gas emissions (EEG) from buildings is gaining increased interest within building sector initiatives and on a regulatory level. In spite of recent harmonisation efforts, reported results of EEG from building case studies display large variations in numerical results due to variations in the chosen indicators, data sources and both temporal and physical boundaries. The aim of this paper is to add value to existing EEG research knowledge by systematically explaining and analysing the methodological implications of the quantitative results obtained, thus providing a framework for reinterpretation and more effective comparison. The collection of over 80 international case studies developed within the International Energy Agency’s EBC Annex 57 research programme is used as the quantitative foundation to present a comprehensive analysis of the multiple interacting methodological parameters. The analysis of methodological parameters is structured by the stepwise methodological choices made in the building EEG assessment practice. Each of six assessment process steps involves one or more methodological choices relevant to the EEG results, and the combination potentials between these many parameters signifies a multitude of ways in which the outcome of EEG studies are affected. [ABSTRACT FROM AUTHOR]

While urban form affects building energy consumption, the pathways, direction and magnitude of the effect are disputed in the literature. This paper uses a unique dataset to examine the effect of urban form on residential electricity consumption in Ningbo, China. Using survey and utility bill data of 534 households in 46 neighborhoods in the city, we model the electricity use of households using a multi-level regression model. We find that neighborhood street configuration and tree shade are important in controlling residential electricity consumption and, consequently, greenhouse gas emissions. Our results suggest that seasonality and dwelling type condition the effect of neighborhood densities on electricity consumption. Neighborhood density is associated with household electricity consumption in summer months, while there is no such association in winter months. As neighborhood density increases, households in slab and tower apartments in dense urban neighborhoods consume more electricity in summer months, which can be partly explained by exacerbated heat island effect. Interestingly, the neighborhood density is negatively associated with summer electricity consumption for single-family houses, suggesting that the effect of neighborhood density is different for different types of dwelling units. [ABSTRACT FROM AUTHOR]

Energy retrofits of buildings usually ignore the amount of embodied energy and greenhouse gas (GHG) emissions needed to reduce the operating energy and related emissions. Focusing on the Greater Melbourne Area (GMA), the fastest growing capital city in Australia, this paper analyses the embodied impacts of different dwelling stock retrofit programs using a combination of a top-down and a bottom-up approach. We look at dwelling stocks that have been built before 2005 (i.e., before a minimum 5-star rating in energy performance was introduced in Australia) because these are expected to consume, without any retrofit or upgrade, about 34.9 TWh of energy or emit 8.57 × 10 6 t-CO 2 eq GHG for heating and cooling every year. Retrofit options to improve their energy star rating range from relatively cheap and easy options (e.g., draught sealing) to relatively expensive options (e.g. double glazing of windows). If all these buildings' energy efficiency is improved to the level of a 6-energy rated dwelling across the metropolitan region, we can save about 25.5 TWh per year in heating and cooling energy (or 6.25 × 10 6 t -CO 2 eq GHG each year). However, the retrofit program is estimated to consume 4.75 TWh of embodied energy, or have 1.89 × 10 6 t -CO 2 eq embodied GHG emissions. This is equivalent to 50% of the annual heating and cooling energy for the stock, or 81% of operational GHG emissions due to heating and cooling of existing dwellings. Considering the total life cycle energy and GHG emissions over the life of the buildings, although reducing the operational heating and cooling energy will remain to be the primary driver for action, the proportion of the embodied impacts’ contribution is expected to increase in the coming years especially as the implementation of net-zero energy/emissions concepts become more commonplace. [ABSTRACT FROM AUTHOR]

The optimization of energy consumption in buildings' HVAC systems plays a crucial role in reducing greenhouse gas emissions worldwide. In new and deeply-renovated buildings, characterized by modulating terminal units and aiming at the maximum exploitation of renewables, an accurate hydraulic balance of the distribution network may become critical, resulting in a significant increase of pumping energy consumptions and a deterioration of indoor thermal comfort conditions. In the present paper, we compare the performance of traditional manual balancing valves and new pressure independent control valves (PICVs), used to balance the hydronic loop of HVAC systems. To perform this analysis, a new MATLAB-Simulink model has been specifically developed to simulate the behavior of PICVs and has been used in an application case study. The efficiency of manual and pressure independent control valves is evaluated numerically by simulating a multi-zone distribution network under variable operating conditions and considering different control strategies of the circulating pump. Results show that in off-design conditions, when some of the branches of the hydraulic network are closed, traditional manual balancing valves are not able to guarantee the nominal mass flow rate in the remaining loops. On the contrary, no significant variations of water mass flow rate are observed when PICVs are adopted, even in partial load conditions. Despite their additional cost, PICVs allow to ensure better indoor thermal comfort sensations for individuals, avoiding under/over-heating of rooms and, moreover, yield a decrease of the pump electric consumption with respect to traditional manual balancing valves. In addition, based on the obtained results, general rules concerning the adoption of PICVs are provided, depending on the extension of the hydraulic loop and the adopted pump control logic. The reported results highlight the role that PICVs can play to ensure energy savings in HVAC systems without penalizing users' indoor comfort conditions. [ABSTRACT FROM AUTHOR]

With the accelerating pace of urbanisation around the world, the planning, development and operation of buildings and precincts have become increasingly important with respect to energy use and the associated carbon footprint of the modern built environment. Over recent decades, much effort, both in research and in practice, has been devoted to building construction and urban planning for the improvement of energy efficiency and greenhouse gas emissions. However, the accuracy of modelling and evaluation of energy and carbon performance for buildings and urban precincts remains limited, affected by inadequate energy intensity data and highly integrated building systems, as well as the complex interactions between buildings and the urban eco-system. This paper presents a critical review of current measures and models for representing and assessing life cycle energy as well as associated emissions profiles at both the building and the precinct levels. It also identifies influential factors and explores interactions among buildings, surrounding environment and user behaviours at the urban precinct level by taking a systems perspective. Based on such a review, this study maps out some key challenges for integrating energy and carbon metrics, and finally proposes a precinct-level system boundary definition and an integrated model following systems thinking. The proposed model can facilitate a critical thinking approach about the evaluations of global energy and emissions, and support the quantification of energy consumption and associated emissions for building precinct systems. [ABSTRACT FROM AUTHOR]

Policy makers have realized that without significant increases in the energy efficiency and notable reductions in the energy use of the household sector, it will be impossible to lower carbon dioxide emissions and mitigate the risks of climate change at the global level. The energy demand in residential buildings is influenced by several parameters, such as national economic growth, climate and weather, demographic structure, and technological development. In this paper, we analyze the determinants of electricity and natural gas consumptions in Italy during the period from 2004 to 2013. We provide estimates of price and income elasticities of the demand for both the energy sources in the residential sector. The role played by both energy price and household income is worth attention because it provides evidence for the occurrence of the direct rebound effect. Therefore, the economic drivers of the energy demand are important to improve the policies meant to reduce greenhouse gas emissions and contrast the global warming. [ABSTRACT FROM AUTHOR]

The overall aim of this work is to develop a thermoelectric (TE) heating system powered by renewable energy that could compete, in the future, with current domestic heating system to reduce the greenhouse gas emissions. In this paper, our results suggest that TE modules can potentially be a solution for domestic indoor space heating whilst using renewable electricity. The test results of the space heating application of TE modules in a laboratory environment (19–21 °C) and outside courtyard low-temperature environment (1–5 °C) demonstrate that sufficient temperature difference can be achieved with TE modules so as to satisfy UK thermal comfort levels. The heating COP test results of TE modules also suggest an acceptable heat pump efficiency for the domestic heating application. Consequently and in order to ascertain its potential feasibility, a domestic heating application of TE modules to a Pre-1900s mid-terrace UK dwelling using hybrid renewable energy of solar energy and wind energy is presented. Our calculations suggest that a TE heating system, powered by local hybrid renewable energy and energy storage, can partly meet the domestic heating demand and could achieve a theoretical energy saving efficiency of 64.03% and reduce the CO 2 emission of 4305.40 kg/year compared with using generic electricity radiator for the domestic space heating whilst the average heating COP remains at 1.8. [ABSTRACT FROM AUTHOR]

In the building sector, the energy and the greenhouse gases embodied in the building materials are becoming increasingly important. Combined with the operational primary energy demand and the end-of-life, the whole life cycle of buildings can be assessed. In this paper, a comprehensive method for calculating the life cycle of individual buildings is presented. First, their material composition has been determined and generic values for the embodied energy, embodied greenhouse gases, energy needed and greenhouse gases emitted during disposal of the different building materials have been calculated. Subsequently these values have been integrated into an urban energy simulation software to simulate energy and emission values for buildings. A given building geometry with four different building standards was considered. The results can help to decide between building refurbishment or demolition and new construction. For example it could be shown that the share of the life cycle stage production compared to the total value rises with a better building insulation standard, as the share of the use stage decreases. The highest building refurbishment standard resulted in the best life cycle performance when compared with less ambitious refurbishment or construction of a new building of today’s standards. [ABSTRACT FROM AUTHOR]

• A methodology for identifying cost-effective solutions for districts is presented. • The usefulness of the methodology is shown in a Case study located in Portugal. • All the analysed centralised approaches are cost-effective. • A carbon emissions neutral district can be achieved maintaining cost-effectiveness. Building renovation plays a key role in reducing greenhouse gas emissions and achieving the climate protection goals. The district scale approach is one of the most effective approaches to accelerate this process of reducing the energy consumption in the building sector as increasing its renovation rates. In this context, the Energy in Buildings and Communities Programme of the IEA, IEA-EBC started in 2017 the project "Annex 75: Cost-Effective Building renovation at District Level Combining Energy Efficiency and Renewables" aiming to explore optimal opportunities of district renovations from a cost-benefit perspective. IEA Annex 75 is a co-operative effort of participants from 13 different countries: Austria, Belgium, China, Czech Republic, Denmark, Germany, Italy, The Netherlands, Norway, Portugal, Spain, Sweden and Switzerland. In this paper, key elements of the methodology developed in Annex 75 project are presented. This methodology aims to facilitate the identification of optimal solutions in different European countries, enabling to explore similarities and differences amongst them, with a particular focus on the balance between energy efficiency measures and renewable energy measures. After a detailed description of the developed methodology, it is also applied to a case study located in Portugal and results obtained are analysed in detail. The paper demonstrates the usefulness of the methodology for evaluating and identifying optimal solutions in renovations at district scale, as well as for successfully addressing the research questions investigated by the Annex 75 project. They also provide some insights regarding the specific case study, showing that, although district systems are not usual in the current Portuguese context, these centralised solutions in renovations at district level are cost-effective interventions that can lead to significant reductions of greenhouse gas emissions and non-renewable primary energy use. [ABSTRACT FROM AUTHOR]

Nowadays, it is well recognized at the international level that the building sector is one of the biggest energy consumers, which made the intervention in this sector the greatest potential for energy consumption reduction and greenhouse emissions mitigation. In Algeria, building sector is responsible of more than 40% of the final energy consumption. Solar energy systems integrated in buildings can be an important solution to this dual problem. The aim of this paper is to estimate the energy performance of a typical single-family bioclimatic house equipped with a solar heating system located in the north Algeria (Algiers) and to investigate its conversion into a zero energy house by installing a grid connected PV system. To achieve this goal, a numerical model of the bioclimatic house coupled with the solar heating system is developed and validated with experimental data. Then, the validated model is used to optimize the adequate size of the solar heating system and to determine its contribution in the production of thermal energy for both DHW preparation and space heating of the house. Finally, a PV system is sized to supply, in parallel with the utility grid, the house with electricity for lighting, appliance and auxiliary electric heater. Furthermore, an economic analysis is made to show the profitability of integration of grid connected PV and solar thermal systems in building. Results show that the conversion of a bioclimatic house into a ZEH using a grid connected PV system, in the north of Algeria weather conditions, present high level of feasibility. However, the return on investment is very high due mainly to the high cost of solar energy components and the very low costs of conventional energy in Algeria. [ABSTRACT FROM AUTHOR]

One of the most lucrative renewable energy sources for supplying energy in future decades is the solar energy. Solar energy can be utilized through both active and inactive systems. Inactive solar systems are the ones which collect and store solar energy without the use of energy-consuming devises such as pumps or controllers, so that the energy can be used at the time of need. This causes the amount of energy consumption in different parts of a building to reach their point of minimum. There are different methods for the utilization of the solar energy in an inactive way, namely solar windows, solar greenhouse method, Trombe wall and aqua wall, atriums, and pools on the roof tops. In this paper, the most common methods of using solar energy in inactive ways, which are atriums, Trombe wall, and solar greenhouse are analyzed. The method of the research is descriptive-analytic so that with better knowledge, modern designs can gain full benefit from these techniques. [ABSTRACT FROM AUTHOR]

Improvements of energy efficiency and reduction of Electricity Consumption (EC) could be pushed by increased knowledge on consumption profiles. This paper contributes to a comprehensive understanding of the EC profiles in a Southwest European city through the combination of high-resolution data from smart meters (daily electricity consumption) with door-to-door 110-question surveys for a sample of 265 households in the city of Évora, in Portugal. This analysis allowed to define ten power consumption clusters using Ward's method hierarchical clustering, corresponding to four distinct types of annual consumption profiles: U shape (sharp and soft), W shape and Flat. U shape pattern is the most common one, covering 77% of the sampled households. The results show that three major groups of determinants characterize the electricity consumption segmentation: physical characteristics of a dwelling, especially year of construction and floor area; HVAC equipment and fireplaces ownership and use; and occupants’ profiles (mainly number and monthly income). The combination of the daily EC data with qualitative door-to-door survey-based data proved to be a powerful data nutshell to distinguish groups of power consumers, allowing to derive insights to support DSOs, ESCOs, and retailers to design measures and instruments targeted to effective energy reduction (e.g. peak shaving, energy efficiency). [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]

Reducing the energy consumption and associated greenhouse gas emissions of urban areas is paramount in research and practice, encompassing strategies to both reduce energy consumption and carbon intensity in both energy supply and demand. Most methods focus on one of these two approaches but few integrate decisions for supply and demand simultaneously. This paper presents a novel model that endogenously simulates energy supply and demand at a district scale on an hourly time scale. Demand is specified for a variety of building uses, and losses and municipal loads are calculated from the number of buildings in the district. Energy supply is modeled using technology-specific classes, allowing easy addition of specific equipment or types of energy generation. Standard interfaces allow expansion of the model to include new types of energy supply and demand. The model can be used for analysis of a single design alternative or optimization over a large design space, allowing exploration of various densities, mixes of uses, and energy supply technologies. An example optimization is provided for a community near San Francisco, California. This example uses 21 building types, 32 combined heat and power engines, and 16 chillers. The results demonstrate the ability to compare performance trade-offs and optimize for three objectives: life cycle cost, annual carbon dioxide emissions, and overall system efficiency. [ABSTRACT FROM AUTHOR]

Building construction has been the main fields of energy consumption and greenhouse gas emission in the world nowadays. With the increase of building height, the amount of carbon dioxide discharged by the building has increased significantly during the entire life cycle. The impact of super tall buildings on the environment has drawn increasing attention due to the huge energy and material consumption. In the life cycle of the building, the carbon emissions are composed of three parts, say embodied carbon, operating carbon and demolition and disposal carbon. Embodied carbon of structural system contributes the most carbon emission during the construction stage of a supper tall building and thus is an important index to measure the environmental impacts of different structural systems for a given super tall building. The embodied carbons and environmental costs of typical super tall building structures for different structural systems are thoroughly analyzed in this study. The distribution of embodied carbons of critical structural members, such as the frame columns, central core walls, structural floors and outrigger trusses are also discussed. At last, this paper analyses the fundamental factors which influence the environmental costs, and the analysis results will provide a guide for the sustainable structural design of super tall buildings. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions are simultaneously exhausting the world's supply of fossil fuels and threatening the global climate. In many developing countries, significant improvement in living standards in recent years due to the accelerating development of their economies has resulted in a disproportionate increase in household energy consumption. Therefore, a major reduction in household carbon emissions (HCEs) is essential if global carbon reduction targets are to be met. To do this, major Organisation for Economic Co-operation and Development (OECD) states have already implemented policies to alleviate the negative environmental effects of household behaviors and less carbon-intensive technologies are also proposed to promote energy efficiency and reduce carbon emissions. However, before any further remedial actions can be contemplated, though, it is important to fully understand the actual causes of such large HCEs and help researchers both gain deep insights into the development of the research domain and identify valuable research topics for future study. This paper reviews existing literature focusing on the domain of HCEs. This critical review provides a systematic understanding of current work in the field, describing the factors influencing HCEs under the themes of household income, household size, age, education level, location, gender and rebound effects. The main quantification methodologies of input–output models, life cycle assessment and emission coefficient methods are also presented, and the proposed measures to mitigate HCEs at the policy, technology and consumer levels. Finally, the limitations of work done to date and further research directions are identified for the benefit of future studies. [ABSTRACT FROM AUTHOR]

Energy consumption forecasting is a critical and necessary input to planning and controlling energy usage in the building sector which accounts for 40% of the world’s energy use and the world’s greatest fraction of greenhouse gas emissions. However, due to the diversity and complexity of buildings as well as the random nature of weather conditions, energy consumption and loads are stochastic and difficult to predict. This paper presents a new methodology for energy demand forecasting that addresses the heterogeneity challenges in energy modeling of buildings. The new method is based on a physical–statistical approach designed to account for building heterogeneity to improve forecast accuracy. The physical model provides a theoretical input to characterize the underlying physical mechanism of energy flows. Then stochastic parameters are introduced into the physical model and the statistical time series model is formulated to reflect model uncertainties and individual heterogeneity in buildings. A new method of model generalization based on a convex hull technique is further derived to parameterize the individual-level model parameters for consistent model coefficients while maintaining satisfactory modeling accuracy for heterogeneous buildings. The proposed method and its validation are presented in detail for four different sports buildings with field measurements. The results show that the proposed methodology and model can provide a considerable improvement in forecasting accuracy. [ABSTRACT FROM AUTHOR]

Naturally ventilated dairy cattle buildings are one of the major sources for ammonia and greenhouse gas emissions to the atmosphere. Generally it is difficult to clean the air from naturally ventilated buildings. In order to reduce the emissions, a hybrid ventilation system, which is natural ventilation combining with mechanical partial pit ventilation, has been developed. By full-scale measurement, this study was to quantify ammonia and methane emissions and to investigate the impacts of climate parameters on gaseous emissions, air exchange rate (ACH) and concentrations at sampling locations in a dairy cattle building with hybrid ventilation. The results revealed that 64–83% of ammonia emissions were collected by partial pit ventilation while 10–50% of methane emission was collected. The results showed that ammonia emission through natural ventilation was around 60% lower than the value found in literatures. ACH was significantly influenced by wind speed and wind direction (wind angle in the range of 135–270°) in summer. The ACH increased generally with wind speed in winter while it hardly changed with wind speed when the windows opening ratio was 6% and even lower. The paper further investigated the impact of wind speed and outdoor temperature on ammonia emissions. [ABSTRACT FROM AUTHOR]

Abstract: High-rise housing, a trend in densely populated cities around the world, increases the energy use for water supply and corresponding greenhouse gas emissions. This paper presents an energy efficiency evaluation measure for water supply system designs and a mathematical model for optimizing pumping energy through the arrangement of water tanks in a building. To demonstrate that the model is useful for establishing optimal design solutions that integrate energy consumption into urban water planning processes which cater to various building demands and usage patterns, measurement data of 22 high-rise residential buildings in Hong Kong are employed. The results show the energy efficiency of many existing high-rise water supply systems is about 0.25 and can be improved to 0.26–0.37 via water storage tank relocations. The corresponding annual electricity that can be saved is 160–410TJ, a 0.1–0.3% of the total annual electricity consumption in Hong Kong. [Copyright &y& Elsevier]

Abstract: The building sector is an energy intensive sector, with great potential to reduce energy needs and environmental pollution. Several measures are being taken to increase the energy efficiency and avoid energy consumption in this sector. A recent trend is the nearly zero energy buildings, which was already adopted by some of the latest regulations, such as the 2010 recast of the European Performance of Buildings Directive (EPBD). However, to reach these goals, especially considering the existing building stock, new retrofit solutions are required, which must be well adapted to the specific building stock needs, and ensure that the building retrofit can achieve the nearly zero energy buildings standards. This paper presents a new prefabricated retrofit module solution for the facades of existing buildings, and also the steps taken to optimise its performance, which includes a judicious choice of materials, 3D modelling, cost–benefit analysis, use of different simulation tools for performance optimisation and prototyping. It is also shown the implementation of the retrofit module within an integrated retrofit approach, whose final goal was to obtain a building with the minimum possible energy consumption and greenhouse gas emissions. [Copyright &y& Elsevier]

Abstract: Retrofitting of existing buildings offers significant opportunities for reducing global energy consumption and greenhouse gas emissions. This is being considered as one of main approaches to achieving sustainability in the built environment at relatively low cost and high uptake rates. Although there are a wide range of retrofit technologies readily available, methods to identify the most cost-effective retrofit measures for particular projects is still a major technical challenge. This paper provides a systematic approach to proper selection and identification of the best retrofit options for existing buildings. The generic building retrofit problem and key issues that are involved in building retrofit investment decisions are presented. Major retrofit activities are also briefly discussed, such as energy auditing, building performance assessment, quantification of energy benefits, economic analysis, risk assessment, and measurement and verification (M&V) of energy savings, all of which are essential to the success of a building retrofit project. An overview of the research and development as well as application of the retrofit technologies in existing buildings is also provided. The aim of this work is to provide building researchers and practitioners with a better understanding of how to effectively conduct a building retrofit to promote energy conservation and sustainability. [Copyright &y& Elsevier]

Abstract: An increasing cause of electricity use and greenhouse gas emissions is from IT equipment such as computers, printers, and servers, with worldwide computer use increasing from 1000 million PCs in 2006, to 1400 million in 2010, and estimated to cause 3% of global electricity demand. Significant energy may be saved if un-used devices are switched off. It was noted that the switch-off rates in the USA for desktop computers in 2006, could be as low as 30%, and there clearly is a need for up-to-date information. It has been difficult to provide accurate figures for switch-off rates, since previous monitoring of IT use has been expensive, requiring specialised equipment and electrical work, labour intensive (using walk-through surveys), or both. This paper demonstrates two low-cost techniques for estimation of unoccupied PC use. Precision and tracking for both were compared with actual power consumption, and subcircuit switch-off rates appeared to be under 76%. Whole building IT related use (including servers) was around 40% of electrical baseload. A desktop switch-off campaign was instigated for accessible equipment, resulting in a 20% reduction in electrical baseload. Extrapolation to a weeknight campaign suggests annual electricity savings of around 12%. [Copyright &y& Elsevier]

Abstract: Nearly two million residential building are built annually in India apart from the offices, commercial and industrial buildings with demand and supply which is increasing year by year. It is essential to conserve the conventional energy by developing energy efficient buildings. Environmental quality and conservation of fossil fuels may become important in the context of limiting of GHGs emission and also reducing cost of materials. The most important stages from point of view of energy intensity: (a) Raw material acquisition; (b) Preparation & Manufacturing;(c) Transportation But this paper broadly considered to analyze the first two parts as the third part of transportation energy vary from location to location, however it has been emphasized in the literature that 1MJ/ tonne /km (diesel) for transporting materials can be integrated for location specific analysis. Besides, Energy estimates given in the literature for various materials such as the Cement 5.85MJ/kg, lime 5.62MJ/kg, LP 2.33MJ/kg (lime 30%, Pozzolana 60% and 10%calcined gypsum), steel 42MJ/kg, Al 236.8MJ/kg, Glass 25.8Mj/kg, Burnt clay brick 4.25MJ, Hollow block 12.3-15MJ, etc have been considered for energy appraisal. It is focused on some issues pertaining to Embodied Energy savings by identifying a few appropriate options for important building components and a comparison of energy in different types of roof and terracing has been made. Energy in different options of alternative systems have been discussed and compared with the energy consumed in conventional specifications to appreciate the consumption of energy in various materials for selection of appropriate materials with reference to energy savings and sustainable development. [Copyright &y& Elsevier]