Whole building life cycle assessment at the design stage: a BIM-based framework using environmental product declaration

PurposeWhole building life cycle assessment (WBLCA) is a key methodology to reduce the environmental impacts in the building sector. Research studies usually face challenges in presenting comprehensive LCA results due to the complexity of assessments at the building level. There is a dearth of methods for the systematic evaluation and optimization of the WBLCA performance at the design stage. The study aims to develop a design optimization framework based on the proposed WBLCA method to evaluate and improve the environmental performance at the building level.Design/methodology/approachThe WBLCA development method is proposed with detailed processes based on the EN 15978 standard. The environmental product declaration (EPD) methods were adopted to ensure the WBLCA is comprehensive and reliable. Building information modeling (BIM) was used to ensure the building materials and assembly contributions are accurate and provide dynamic material updates for the design optimization framework. Furthermore, the interactive BIM-LCA calculation processes were demonstrated for measuring the environmental impacts of design upgrades. The TOPSIS-based LCA results normalization was selected to conduct the comparisons of various building design upgrades.FindingsThe case study conducted for a residential building showed that the material embodied impacts and the operational energy use impacts are the two critical factors that contribute 60–90% of the total environmental impacts and resource uses. Concrete and wood are the main material types accounting for an average of 65% of the material embodied impacts. The air and water heating for the house are the main energy factors, as these account for over 80% of the operational energy use. Based on the original WBLCA results, two scenarios were established to improve building performance through the design optimization framework.Originality/valueThe LCA results show that the two upgraded building designs create an average of 5% reduction compared with the original building design and improving the thermal performance of the house with more insulation materials does not always reduce the WBLCA results. The proposed WBLCA method can be used to compare the building-level environmental performances with the similar building types. The proposed framework can be used to support building designers to effectively improve the WBLCA performance.

Life cycle energy analysis of a green building in Vietnam

The paper presents the life cycle energy analysis (LCEA) of an office green building in Hanoi, Vietnam to prove the advantages of green buildings regarding energy efficiency and environmental effects. The case study building is a concrete structured one, which consists of 3 basements, 17 floors, and 1 attic with a gross area of 14,112 m2. In the study, the building’s embodied energy is determined based on the contained energy coefficient of the ith material and its quantity needed. Whereas, the operating energy is computed according to the annual energy consumption of the building, which is stimulated by the EnergyPlus simulation software. Relying on the relative share of the demolition energy with the life cycle energy that has been proposed by previous publications, this category will be estimated. Results showed that the initial embodied energy contributed the largest share to the life cycle energy (61.37%), followed by operational energy (27.61%). It also indicated that the percentage share of the operational energy of a green building is much lower than that of other buildings. The primary reason for this is associated with the usage of environmentally friendly materials and energy-saving equipment in the design option of the green building. Therefore, it can be convincing evidence that may help to change the mindset of decision-makers in Vietnam about green buildings.

Two-Stage Lifecycle Energy Optimization of Mid-Rise Residential Buildings with Building-Integrated Photovoltaic and Alternative Composite Façade Materials

Reducing the lifecycle energy use of buildings with renewable energy applications has become critical given the urgent need to decarbonize the building sector. Multi-objective optimizations have been widely applied to reduce the operational energy use of buildings, but limited studies concern the embodied or whole lifecycle energy use. Consequently, there are issues such as sub-optimal design solutions and unclear correlation between embodied and operational energy in the current building energy assessment. To address these gaps, this study integrates a multi-objective optimization method with building energy simulation and lifecycle assessment (LCA) to explore the optimal configuration of different building envelopes from a lifecycle perspective. Major contributions of the study include the integrated optimization which reflects the dynamics of the whole lifecycle energy use. Insights from the study reveal the optimal configuration of PV and composite building façades for different regions in sub-Saharan Africa. The lifecycle energy use for the optimized building design resulted in 24.59, 33.33, and 36.93% energy savings in Ghana, Burkina Faso, and Nigeria, respectively. Additionally, PV power generation can efficiently cover over 90% of the total building energy demand. This study provides valuable insights for building designers in sub-Saharan Africa and similar areas that minimize lifecycle energy demand.

Application of Artificial Neural Networks for Virtual Energy Assessment

A Virtual energy assessment (VEA) refers to the assessment of the energy flow in a building without physical data collection. It has been occasionally conducted before the COVID-19 pandemic to residential and commercial buildings. However, there is no established framework method for conducting this type of energy assessment. The COVID-19 pandemic has catalysed the implementation of remote energy assessments and remote facility management. In this paper, a novel framework for VEA is developed and tested on case study buildings at the University of Melbourne. The proposed method is a hybrid of top-down and bottom-up approaches: gathering the general information of the building and the historical data, in addition to investigating and modelling the electrical consumption with artificial neural network (ANN) with a projection of the future consumption. Through sensitivity analysis, the outdoor temperature was found to be the most sensitive (influential) parameter to electrical consumption. The lockdown of the buildings provided invaluable opportunities to assess electrical baseload with zero occupancies and usage of the building. Furthermore, comparison of the baseload with the consumption projection through ANN modelling accurately quantifies the energy consumption attributed to occupation and operational use, referred to as ‘operational energy’ in this paper. Differentiation and quantification of the baseload and operational energy may aid in energy conservation measures that specifically target to minimise these two distinct energy consumptions.

Reducing Gas Emission Mechanisms for Hydrocarbon Storage Tanks

Volatile Organic Compounds (VOC) which are emitted from tank farms of petroleum refineries are considered to cause harmful impacts to the environment and people. This paper presents the methodology of assessing potential targets for reduction of emissions, as well as proposed control mechanisms and their reductions, for hydrocarbon storage tanks at Jebel Al Dhanna Terminal. Some of the emissions reduction opportunities which are covered include aluminum dome retrofits, seal integrity improvement and guide pole treatments. The objective is to find significant reduction opportunities (from between 50% to 90% of current tank configurations) using passive technologies which prevent or inhibit emissions without the use of additional operational energy or active systems that would otherwise require significant maintenance or operational expense.

Significant effect of SDS on the optimum operating temperature of ZnO nanosheets gas-sensitive materials

Many methods have been used to reduce the operational energy consumption of ZnO gas-sensitive material effectively. In this paper, different morphologies of ZnO nanomaterials are respectively prepared in the anionic hydrophilic surfactant sodium lauryl sulfate (SDS) with different concentrations as soft templates by hydrothermal method. The influence of SDS concentrations is investigated on the morphology of materials under the conditions of a weak alkali environment with the same pH, and their gas sensitivity after annealing with the same temperature and time. The morphologies and phase structures of all samples are characterized by FESEM and XRD, and their gas-sensitive properties are analyzed by CGS-1TP. Interestingly, the experimental results show that the optimal working temperature of ZnO gas-sensitive materials containing low concentration SDS is reduced by nearly 55% than that of containing 10 times this concentration, and its sensitivity is also slightly improved. The possible mechanism by which the SDS concentration affects the gas sensitivity of the material is also proposed.

Towards an integrated multi-scale zero energy building framework for residential buildings

<p>In most developed economies, buildings are directly and indirectly accountable for at least 40% of the final energy use. Consequently, most world cities are increasingly surpassing sensitive environmental boundaries and continue to reach critical biophysical thresholds. Climate change is one of the biggest threats humanity faces today and there is an urgent need to reduce energy use and CO₂ emissions globally to zero or to less than zero, to address climate change. This often leads to the assumption that buildings must reduce energy demand and emit radically less CO₂ during construction and occupation periods. Certainly, this is often implemented through delivering ‘zero energy buildings’. The deployment of residential buildings which meet the zero energy criteria thereby allowing neighbourhoods and cities to convert to semi-autonomous energy systems is seen to have a promising potential for reducing and even eliminating energy demand and the associated greenhouse gas emissions. However, most current zero energy building approaches focus solely on operational energy overlooking other energy uses such as embodied energy and user transport energy. Embodied energy constitutes all energy requirements for manufacturing building materials, construction and replacement. Transport energy comprises the amount of energy required to provide mobility services to building users. Zero energy building design decisions based on partial evaluation and quantification approaches might result in an increased energy demand at different or multiple scales of the built environment. Indeed, recent studies have demonstrated that embodied and transport energy demands account for more than half of the total annual energy demand of residential buildings built based on zero energy criteria. Current zero energy building frameworks, tools and policies therefore may overlook more than ~80% of the total net energy balance annually. The original contribution of this thesis is an integrated multi-scale zero energy building framework which has the capacity to gauge the relative effectiveness towards the deployment of zero energy residential buildings and neighbourhoods. This framework takes into account energy requirements and CO₂ emissions at the building scale, i.e. the embodied energy and operation energy demands, and at the city scale, i.e. the embodied energy of related transport modes including infrastructure and the transport operational energy demand of its users. This framework is implemented through the development of a quantification methodology which allows the analysis and evaluation of energy demand and CO₂ emissions pertaining to the deployment of zero energy residential buildings and districts. A case study, located in Auckland, New Zealand is used to verify, validate and investigate the potential of the developed framework. Results confirm that each of the building (embodied and operational) and transport (embodied and operational) energy requirements represent a very significant share of the annual overall energy demand and associated CO₂ emissions of zero energy buildings. Consequently, rather than the respect of achieving a net zero energy building balance at the building scale, the research has revealed that it is more important, above all, to minimise building user-related and transportation energy demand at the city scale and maximise renewable energy production coupled with efficiency improvements at grid level. The application of the developed evaluation framework will enable building designers, urban planners, researchers and policy makers to deliver effective multi-scale zero energy building strategies which will ultimately contribute to reducing the overall environmental impact of the built environment today.</p>

Towards an integrated multi-scale zero energy building framework for residential buildings

<p>In most developed economies, buildings are directly and indirectly accountable for at least 40% of the final energy use. Consequently, most world cities are increasingly surpassing sensitive environmental boundaries and continue to reach critical biophysical thresholds. Climate change is one of the biggest threats humanity faces today and there is an urgent need to reduce energy use and CO₂ emissions globally to zero or to less than zero, to address climate change. This often leads to the assumption that buildings must reduce energy demand and emit radically less CO₂ during construction and occupation periods. Certainly, this is often implemented through delivering ‘zero energy buildings’. The deployment of residential buildings which meet the zero energy criteria thereby allowing neighbourhoods and cities to convert to semi-autonomous energy systems is seen to have a promising potential for reducing and even eliminating energy demand and the associated greenhouse gas emissions. However, most current zero energy building approaches focus solely on operational energy overlooking other energy uses such as embodied energy and user transport energy. Embodied energy constitutes all energy requirements for manufacturing building materials, construction and replacement. Transport energy comprises the amount of energy required to provide mobility services to building users. Zero energy building design decisions based on partial evaluation and quantification approaches might result in an increased energy demand at different or multiple scales of the built environment. Indeed, recent studies have demonstrated that embodied and transport energy demands account for more than half of the total annual energy demand of residential buildings built based on zero energy criteria. Current zero energy building frameworks, tools and policies therefore may overlook more than ~80% of the total net energy balance annually. The original contribution of this thesis is an integrated multi-scale zero energy building framework which has the capacity to gauge the relative effectiveness towards the deployment of zero energy residential buildings and neighbourhoods. This framework takes into account energy requirements and CO₂ emissions at the building scale, i.e. the embodied energy and operation energy demands, and at the city scale, i.e. the embodied energy of related transport modes including infrastructure and the transport operational energy demand of its users. This framework is implemented through the development of a quantification methodology which allows the analysis and evaluation of energy demand and CO₂ emissions pertaining to the deployment of zero energy residential buildings and districts. A case study, located in Auckland, New Zealand is used to verify, validate and investigate the potential of the developed framework. Results confirm that each of the building (embodied and operational) and transport (embodied and operational) energy requirements represent a very significant share of the annual overall energy demand and associated CO₂ emissions of zero energy buildings. Consequently, rather than the respect of achieving a net zero energy building balance at the building scale, the research has revealed that it is more important, above all, to minimise building user-related and transportation energy demand at the city scale and maximise renewable energy production coupled with efficiency improvements at grid level. The application of the developed evaluation framework will enable building designers, urban planners, researchers and policy makers to deliver effective multi-scale zero energy building strategies which will ultimately contribute to reducing the overall environmental impact of the built environment today.</p>