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Buildings are responsible for the consumption of around 40% of energy in the world and account for one-third of greenhouses gas emissions. In Saudi Arabia, residential buildings consume half of total energy among other building sectors. This study aims to explore the impact of sixteen envelope variables on the operational and embodied carbon of a typical Saudi house with over 20 years of operation.

A simulation approach has been adopted to examine the effects of envelope variables including external wall type, roof type, glazing type, window to wall ratio (WWR) and shading device. To model the building and define the envelope materials and quantify the annual energy consumption, DesignBuilder software was used. Following modelling, operational carbon was calculated. A “cradle-to-gate” approach was adopted to assess embodied carbon during the production of materials for the envelope variables based on the Inventory of Carbon Energy database.

The results showed that operational carbon represented 90% of total life cycle carbon, whilst embodied carbon accounted for 10%. The sensitivity analysis revealed that 25% WWR contributes to a significant increase in operational carbon by 47.4%. Additionally, the efficient block wall with marble has a major embodiment of carbon greater than the base case by 10.7%.

This study is a contribution to the field of calculating the embodied and operational carbon emissions of a residential unit. Besides, it provides an examination of the impact of each envelope variable on both embodied and operational carbon. This study is limited by the impact of sixteen envelope variables on the embodied as well as operational carbon.

This study is the first attempt on investigating the effects of envelop variables on carbon footprint for residential buildings in Saudi Arabia.

Operational energy use in buildings accounts for 28% of global energy demand. One method to reduce operational energy is upgrading old appliances to more efficient ones. In Australia, the most common residential heating type is reverse-cycle heating, followed by gas heating. This article aims to determine the energy balance resulting from a gas heating upgrade through a life cycle assessment (LCA).

Extensive primary data were collected for operational energy performance of 61 ducted gas heating upgrades. To address the scarcity of data on material composition, one ducted gas heater was deconstructed and assessed in terms of material composition (types and weights). The comparison between embodied energy and operational energy savings allows us to establish whether operational energy savings offset the embodied energy incurred with the upgrade. The end of life stage of the old appliance, as well as the production, construction and use stage of the new appliance were assessed.

The results show that the operational energy savings offset the following impact categories: global warming, ozone layer depletion, aquatic acidification, nonrenewable energy and carcinogens. Only the mineral extraction is not offset by the operational energy savings. The results clearly demonstrate that operational energy savings outweigh the embodied energy and therefore contribute positively to the environment.

This study is the first to focus on the LCA of building services through extensive primary data collection and a focus on a high number of appliances. This supports ongoing energy efficient upgrades in Australia and paves the way for further, similar studies to confirm or disprove these findings in other parts of the world.

The construction industry has focused on operational and embodied energy of buildings as a way of becoming more sustainable, however, with more emphasis on the former. The purpose of this paper is to highlight the impact that embodied energy of construction materials can have on the decision making when designing buildings, and ultimately on the environment. This is an important aspect that has often been overlooked when calculating a building's carbon footprint; and its inclusion this approach presents a more holistic life cycle assessment.

A building project was chosen that is currently being designed; the design team for the project have been tasked by the client to make the facility exemplary in terms of its sustainability. This building has a limited construction palette; therefore the embodied energy component can be accurately calculated. The authors of this paper are also part of the design team for the building so they have full access to Building Information Modelling (BIM) models and production information. An inventory of materials was obtained for the building and embodied energy coefficients applied to assess the key building components. The total operational energy was identified using benchmarking to produce a carbon footprint for the facility.

The results indicate that while operational energy is more significant over the long term, the embodied energy of key materials should not be ignored, and is likely to be a bigger proportion of the total carbon in a low carbon building. The components with high embodied energy have also been identified. The design team have responded to this by altering the design to significantly reduce the embodied energy within these key components – and thus make the building far more sustainable in this regard.

It may be is a challenge to create components inventories for whole buildings or for refurbishments. However, a potential future approach for is application may be to use a BIM model to simplify this process by imbedding embodied energy inventories within the software, as part of the BIM menus.

This case study identifies the importance of considering carbon use during the whole-life cycle of buildings, as well as highlighting the use of carbon offsetting. The paper presents an original approach to the research by using a “live” building as a case study with a focus on the embodied energy of each component of the scheme. The operational energy is also being calculated, the combined data are currently informing the design approach for the building. As part of the analysis, the building was modelled in BIM software.

The purpose of this paper is to identify the sustainability conditions of primary schools in Turkey within the scope of the life cycle assessment (LCA). It is aimed to develop optimum alternatives to reduce the environmental impact of primary schools and reach environmental sustainability targets of the sustainable development goals in Turkey.

From the construction project of 103 buildings located in Istanbul, 10 case buildings with various typical plans were chosen for analysis. The results regarding their life cycle energy and carbon emission for material production, operation and maintenance stages were calculated for a lifespan of 50 years. Results were evaluated and compared within the scope of environmental sustainability. Optimum alternatives for improving the environmental sustainability and performances of selected case buildings’ facades were developed, and the life cycle energy and carbon emission for proposed conditions were calculated. The obtained results were evaluated for current and proposed conditions.

Results showed that reinforced concrete material contributes the most to the life cycle-embodied energy and CO₂ emission of buildings. Cooling load increases the life cycle operational energy (LCOE) and CO₂ emission of buildings. Using high-performance glazing significantly reduces LCOE and CO₂ emission. Recycled and fiber-based materials have significant potential for reducing life cycle-embodied energy and CO₂ emission.

This study has been developed in response to achieving sustainable development targets on public buildings in Turkey. In this regard, external walls of primary schools were analyzed within the scope of LCA and recommendations were made to contribute to the policies and regulations requested by the Government of Turkey. This study proves that alternative and novel materials have great potential for achieving sustainable public buildings. The study answers to questions about reducing the environmental impact of primary school buildings by using LCA approach with a holistic point of view.

Global warming and climate change is one of the biggest issues facing humanity in this century; its effects are felt on the highest peaks of Mount Everest to the low-lying islands in the India Ocean. This century marked the highest amount of carbon dioxide (CO₂) emitted, breaking records of the past 650,000 years, and we have pushed the climate to “a point of no return”. Much of the climate contribution has been linked to humanity’s thirst for higher living standards and lifestyle, which has led to higher consumerism, depletion of earth’s resources, production of massive waste and carbon emissions. Fast forward from the sustainability agenda of Brundtland set in 1987 and the increasing demand for energy consumption to cater for the current global inhabitants, many “green” efforts have been taken by the building industry to reduce the overall environmental impact. This purpose of this study is to compare energy performance of a conventional office building with a green certified building.

This paper tries to bridge the performance gap by comparing measured operational energy consumption and carbon emission of Green Building Index (GBI)-certified office buildings in Kuala Lumpur, to determine whether “green buildings” are performing as intended in reducing their environmental impact.

This paper highlighted and compared operational energy consumption and carbon emissions of a GBI-certified office with a conventional office building in Malaysia. The paper also discusses the performance gap issue and its common causes, and aims to compare predicted energy and operational energy performance of buildings.

Initiatives such as “green” or “sustainable” design have been at the forefront of architecture, while green assessment tools have been used to predict the energy performance of a building during its operational phase. There is still a significant performance gap between predicted or simulated energy measurements to actual operational energy consumption. The need to measure actual performance of these so-called “green buildings” is important to investigate if there is a performance gap and whether these buildings can perform better than conventional buildings. Understanding why the performance gap occurs is a step in reducing actual and predicted energy performance in buildings.

This paper aims to consider the embodied energy of building materials in the context of greenhouse gas emission mitigation strategies. Previous practice and research are highlighted where they have the potential to influence design decisions. Latest embodied energy figures are indicated, and the implications of applying these figures to whole buildings are discussed. Several practical examples are given to aid building designers in the selection of building materials for reduced overall life cycle greenhouse gas emissions.

Buildings are major contributors to greenhouse gases (GHG) along the various stages of the building life cycle. A range of tools have been utilised for estimating building energy use and environmental impacts; these are time-consuming and require massive data that are not necessarily available during early design stages. Therefore, this study aimed to develop an Environmental Impacts Cost Assessment Model (EICAM) that quantifies both energy and environmental costs for residential buildings.

An Artificial Neural Network (ANN) was employed to develop the EICAM. The model consists of six input parameters, including wall type, roof type, glazing type, window to wall ratio (WWR), shading device and building orientation. In addition, the model calculates four measures: annual energy cost, operational carbon over 20 years, envelope embodied carbon and total carbon per square metre. The ANN architecture is 6:13:4:4, where the conjugate gradient algorithm was applied to train the model and minimise the mean squared error (MSE). Furthermore, regression analysis for the ANN prediction for each output was performed.

The MSE was minimised to 0.016 while training the model. Also, the correlation between each ANN output and the actual output was very strong, with an R² value for each output of almost 0.998. Moreover, validation was conducted for each output, with the error percentages calculated at 0.26%, 0.25%, 0.03% and 0.27% for the annual energy cost, operational carbon, envelope materials embodied carbon and total carbon per square metre, respectively. Accordingly, the EICAM contributes to enhancing design decision-making concerning energy consumption and carbon emissions in the early design stages.

This study provides theoretical implications to the domain of building environmental impact assessment through illustrating a systematic approach for developing an energy-based prediction model that generates four environmental-oriented outputs, namely energy cost, operational energy carbon, envelope embodied carbon, and total carbon. The model developed has practical implications for the architectural/engineering (A/E) industries by providing a useful tool to easily predict environmental impact costs during the early design phase. This would enable designers in Saudi Arabia to make effective design decisions that would increase sustainability in the building life cycle.

By providing a holistic predictive model entitled EICAM, this study endeavours to bridge the gap between energy costs and environmental impacts in a predictive model for Saudi residential units. The novelty of this model is that it is an alternative tool that quantifies both energy cost, as well as building’s environmental impact, in one model by using a machine learning approach. Besides, EICAM predicts its outcomes more quickly than conventional tools such as DesignBuilder and is reliable for predicting accurate environmental impact costs during early design stages.

Crucial transition of the Indian residential building sector into a low-emission economy require an in-depth understanding of the potentials for retrofitting the existing building stock. There are, however, limited studies that have recognised the interdependencies and trade-offs in the embodied energy and life cycle impact assessment of retrofit interventions. This research appraises the life cycle assessment and embodied energy output of a residential building in India to assess the environmental implications of selected retrofit scenarios.

This study utilises a single case study building project in South India to assess the effectiveness and impact of three retrofit scenarios based on life cycle assessment (LCA) and embodied energy (EE) estimates. The LCA was conducted using SimaPro version 9.3 and with background data from Ecoinvent database version 3.81. The EE estimates were calculated using material coefficients from relevant databases in the published literature. Monte Carlo Simulation is then used to allow for uncertainties in the estimates for the scenarios.

The three key findings that materialized from the study are as follows: (1) the retrofitting of Indian residential buildings could achieve up to 20% reduction in the life cycle energy emissions, (2) the modification of the building envelope and upgrading of the building service systems could suffice in providing optimum operational energy savings, if the electricity from the grid is sourced from renewable plants, and (3) the production of LEDs and other building services systems has the highest environmental impacts across a suite of LCA indicators.

The retrofitting of residential buildings in India will lead to better and improved opportunities to meet the commitments in the Paris Climate Change Agreement and will lead to enhanced savings for building owners.

This paper proposes an intact framework for building life cycle energy estimation (LCEE), which includes three major energy sources: embodied, operational and mobile.

A systematic review is conducted to summarize the selected 109 studies published during 2012–2021 related to quantifying building energy consumption and its major estimation methodologies, tools and key influence parameters of three energy sources.

Results show that the method limitations and the variety of potential parameters lead to significant energy estimation errors. An in-depth qualitative discussion is conducted to identify research knowledge gaps and future directions.

With societies and economies developing rapidly across the world, a large amount of energy is consumed at an alarming rate. Unfortunately, its huge environmental impacts have forced many countries to take energy issues as urgent social problems to be solved. Even though the construction industry, as the one of most important carbon contributors, has been constantly and academically active, researchers still have not arrived at a clear consensus for system boundaries of life cycle energy. Besides, there is a significant difference between the actual and estimated values in countless current and advanced energy estimation approaches in the literature.

The purpose of this paper is to develop the empirically tested framework about the knowledge and perception about sustainability of building materials in Prishtina, Kosovo from the perspective of users, construction industry and facility managers.

A survey of representative sections of the population was designed and carried out in the capital city of Kosovo to determine the knowledge and perception of the population about the sustainability of building materials and to determine the main criteria of selection of sustainable building materials. The study may be used as guidelines for sustainable real estate developers in Prishtina during the materials selection process. Qualitative interviews were conducted with architects, consulting engineering companies, construction companies and facility managers from the region of Prishtina with open-ended questions also being used.

Results of quantitative research find that embodied energy, durability and low energy consumption are used as key criteria that influence the materials selection process on the part of users. The results of the cross-case analysis of qualitative measure the perceptions of construction industry and facility managers, according to which durability to a large degree is the main criterion for selection of sustainable building materials followed by embodied energy and low energy consumption.

The study of measurement of level of knowledge and perception about sustainability of building materials in Kosovo focuses only on one pilot city; hence, further research is needed throughout Kosovo to validate the empirically tested tool within other geographical settings in Kosovo.

This survey represents the first quantification of knowledge and perception regarding the sustainability of building materials among users, construction sector and facility managers.