Academic literature on the topic 'Embodied Energy (EE)'

Siklus bangunan terdiri atas berbagai tahapan sepanjang daur hidup bangunan tersebut, dimana setiap tahapan mengandung kebutuhan energi yang menyertai aktivitasnya. Energi ini disebut Embodied Energy (EE). Nilai EE dapat menjadi dasar perhitungan potensi besaran Emission Carbon (EC) yang akan ditimbulkan suatu bangunan sehingga potensi dampak lingkungan akibat EC dapat diukur. Paper ini bertujuan menjelaskan hasil perhitungan EE material pada pembangunan perumahan sederhana di Indonesia. Harapannya adalah nilai EE ini dapat digunakan sebagai pertimbangan dalam upaya mitigasi energi, yang pada akhirnya akan menjadi mitigasi potensi EC dan mencegah dampak kerusakan lingkungan sejak dini. Di sisi lain, kebutuhan perumahan sederhana yang bersifat massal membutuhkan pasokan material bangunan dalam jumlah besar. Mitigasi energi akibat penggunaan material yang besar ini diharapkan dapat dilakukan melalui pengukuran nilai EE. Metode penelitian yang digunakan adalah metode perhitungan nilai EE material perumahan sederhana serta analisis data secara kuantitatif, sehingga diketahui nilai EE yang signifikan dihasilkan oleh jenis pekerjaan tertentu, yang hasilnya digunakan untuk merumuskan usulan mitigasi. Hasil perhitungan EE material pada tipe-tipe perumahan sederhana menunjukkan bahwa komponen bangunan dengan nilai EE terbesar adalah pada pekerjaan dinding (35%-45%) dan pekerjaan atap bangunan (46%-48%). Berdasarkan hal itu, maka kedua item pekerjaan tersebut akan menjadi fokus mitigasi, melalui upaya penurunan nilai EE material yang tinggi melalui perencanaan desain dan usulan subtitusi material. Kunci keberhasilan dari kedua mitigasi energi tersebut ada pada efisiensi penggunaan volume material dan penggunaan material alternatif dengan nilai EE rendah yang dipilih untuk subtitusi.

Abstract Buildings present a unique opportunity to not just effectively decrease global energy use but also drastically reduce nearly 40% of global carbon emissions to help mitigate the ongoing climate change. Although most of the building energy use is attributed to building operations as operational energy (OE), a portion of it is termed embodied energy (EE) that is consumed in building construction, transportation, and material production activities. EE of a building, therefore, includes energy consumed directly in onsite and offsite construction and transportation and indirectly through material consumption since each construction material consumes energy in its production and transportation. Like EE, buildings also consume significant amounts of fresh water directly and indirectly as embodied water (EW) in their construction, which is becoming a major concern globally. As fresh water is also depleted in producing and refining energy sources used as EE, a portion of this EW is attributed to energy-related water use (EREW). Most research so far has been focusing on the energy and carbon emission dimensions of buildings overlooking the equally important aspect of water use, which is also crucial for delivering a truly environmentally sustainable building. In this study, an input-output-based hybrid (IOH) model is created to compute and compare EE and EW of 10 higher education buildings and examine the correlation of the calculated EE and EW values. The results demonstrate that the total EE and electricity EE of the study buildings share a very strong positive correlation (r2 = 0.93-0.99) with the buildings’ total EW at the building level. This correlation, however, weakens at the material level. The share of EREW in the total EW ranges from 9-13%, which indicates that reducing just EE may not help decrease EW, and additional efforts may be needed to address EW and reduce fresh water use in building construction.

Abstract Buildings consume over 40% of global energy in their construction and operations contributing to over 39% of global carbon emission each year. This huge environmental footprint presents an excellent opportunity to reduce energy use and help deliver an environmentally sustainable built environment. Most of the energy is consumed by buildings as embodied energy (EE) and operational energy (OE). EE is used directly and indirectly during buildings’ initial construction, maintenance and replacement, and demolition phases through construction products and services. OE is used in the processes of heating, cooling, water heating, lighting, and operating building equipment. Most environmental optimization research has been centered on energy and carbon emission overlooking another critical sustainability aspect, water use. Each building also consumes a significant amount of freshwater as embodied water (EW) or virtual water in its initial construction, maintenance and replacement, and demolition phases. Since each primary and secondary energy source depletes water in its extraction, refinement or production, there is also a water expense associated with EE and OE use that must also be included in total EW use. The total EW, therefore, includes both non-energy and energy related water use. Research suggests that there are tradeoffs between EE and EW that may complicate design decisions such as material selection for environmental sustainability. In other words, a material selected for its lower EE may have higher EW and selecting such a material may not help reach environmental sustainability goals since water scarcity is becoming a grave problem. In this paper, we created an input-output-based hybrid (IOH) model for calculating and comparing EE and EW of building materials frequently used in building construction. The main goal is to examine and highlight any tradeoffs that may exist when selecting one material over another. The results reveal that there is a weak correlation between EE and total EW that is the sum of energy and non-energy water use, which means that a design decision made solely based on EE may conflict with EW. The share of energy related water use in total EW of construction materials also varies significantly (2.5%-31.2%), indicating that reducing energy use alone may not be sufficient to reduce freshwater use; additional efforts may be needed to decrease the use of materials and processes that are water intensive. The results of this study are significant to achieving the goal of creating a truly sustainable built environment.

Abstract Buildings consume over 40% of global energy annually in their initial construction and operation as embodied and operational energy, contributing to over 39% of global carbon emissions. Embodied energy (EE) is consumed directly in construction processes and indirectly using construction materials, each of which uses energy during its manufacturing. All direct and indirect embodied energies used in maintenance, repair, and replacement processes of buildings is termed recurrent embodied energy (REE). Because REE accrues over 50-100-year life cycle of buildings, it may be equal to, or more than the initial embodied energy (IEE) used during buildings’ construction. Both REE and IEE must be optimized to help effectively reduce the environmental burdens of buildings. However, calculating IEE and REE is a data-intensive process requiring temporally representative data that may not be readily available. Consequently, studies may use older data. This paper offers a temporal analysis of the IEE and REE of healthcare buildings to demonstrate how energy source-specific EE values may change over time and introduce errors in IEE and REE calculations if old data is used. Using macroeconomic modeling, the IEE and REE intensities of healthcare building sector are computed. The results indicate that using 5-year and 10-year-old data may underestimate IEE by 5% and overestimate it by 26%, respectively, whereas the REE may be overestimated by 20% and 33%, respectively. The results also show that the share of electricity in EE may be increasing over time. The findings underscore the importance of using temporally representative EE data for energy analysis.

Embodied energy (EE) property of building material is a great determinant of the performance of a building. The dearth of information on EE of locally sourced building materials (LSBMs) constitutes a challenge to affordable housing in Nigeria. In this paper, a review of the previous literature, unfilled gaps in those works, and future directions in embodied energy research for LSBMs is presented to evolve a Nigerian perspective. A constructive non-meta analytic methodology was adopted for the paper. This was followed by classification and comparison of snapshot literature in the embodied energy of building materials. Insightful sources of information for the study were drawn from a vast body of knowledge both documented literature and some interviews with knowledgeable personnel in the area of a built environment. From the survey, energy management opportunities were revealed, which would not have been apparent from a specific building case study alone. There are distinctions in the literature with this currentpaper for a Nigerian case study: none have addressed the embodied energy coefficient of materials. Also, the status of embodied energy studies, for these materials, is at a low profile and the few investigations carried out focused on life cycle operating energy of buildings. These research gaps evidently imply abundant research opportunities that await exploitation in the building industry. This paper adds to an existing body of knowledge on the use of EE index to promote and optimize the selection of LSBMs as alternative to imported building materials. We hope engineers, estate developers and architects would find it useful for making an informed decision in the design of resilient buildings using indigenous materials. Keywords: building material, embodied energy, system boundary, capacity, building information modelling, Nigeria.

Two important factors that have been put in the limelight in the current age are environmental concerns and sustainable future. The building sector has emerged as an important player in this matter due to their contribution into the large share of resources and energy consumption as well as harmful greenhouse gas emission. This paper discusses the percentage of embodied energy (EE) in two common building wall materials in Malaysia: steel and concrete. Concrete is used in concrete non-load bearing walls and steel is used to manufacture curtain walls. Although there are more materials used in the selected case studies, steel and concrete possess the high amount of embodied energy. Thus, the concrete wall and curtain wall in the lifecycle analysis (LCA) pre-use phase in high-rise office buildings in Malaysia are considered in this research. GaBi software is used to evaluate and calculate embodied energy in the case studies. The functional unit for this LCA study is determined as one cubic meter of concrete non-load bearing wall and curtain wall. In order to determine the components included in the analysis, input-output flowcharts are created for each process. The comparison of these walls shows that curtain wall has more embodied energy than concrete. The highest amount of embodied energy in curtain wall construction for case B is 4873.89 MJ, and for the case A is 4851.09 MJ approximately. The amount of EE in the concrete non-load bearing wall for both case studies are the lowest amount, with 278.85 MJ for case A and 280.66 MJ for case B. Results also show that the manufacturing of materials is the biggest contribution to the amount of EE at more than 50%, whereas transportation is between 1.83% and 3.77% only.

This paper empirically investigates the variations of embodied energy (EE) and carbon (EC) intensities of materials and identifies their parameter variations in hybrid life cycle assessment (LCA). These parameters include energy tariff, primary energy factor, disaggregation constant, emission factor, and price fluctuation. Hybrid LCA has been conducted to expand the system boundary by filling the gaps in traditional LCA data inventories. The Malaysian Input-Output (I-O) tables are used to derive indirect energy and carbon intensities which are then combined to take advantages of detailed process LCA. The results revealed that maximum increase in energy tariffs and material price fluctuations were the key parameters and issues leading to higher variations in EE and EC intensity values. Other parameters – such as maximum increase in primary energy factor, emission factor and excluding disaggregation constant – have a slight impact upon EE and EC intensity variations. Building materials with high indirect energy in the upstream boundary of materials production have high influence on hybrid LCA variation. Therefore, any decision relating to these materials should be considered carefully.

Purpose Many studies have focused on embodied energy (EE) and operational energy (OE), but a shortage of studies on decision making, which involves several decision makers whose decisions can affect the energy performance of buildings, is evident. From the stages of the project life cycle, the design stage is identified as the ideal stage for integrating energy efficiency into buildings. Therefore, the purpose of this paper is to revisit the role of professionals in designing energy-conscious buildings with low EE and OE. Design/methodology/approach This study administered a qualitative approach. Data were collected through semi-structured interviews only with 12 experts, due to the lack of expertise in the subject matter. The data were analyzed using manual content analysis. Findings The outcomes revealed the necessity to revisit the role of construction professionals in terms of adopting energy-efficient building design concepts from the project outset. The roles of the key professional groups (i.e. architects, structural engineers, services engineers and quantity surveyors) were identified through this research. Common issues in designing energy-efficient buildings and the means of addressing such problems were outlined. Originality/value This study contributes to the knowledge by revisiting the roles of construction professionals and proposing how they could leverage their strengths to play the important role and contribute collectively to design buildings with both low OE and EE.

This work assesses the energy requirements and CO2 emissions of a building made of Lime Hemp Concrete (LHC) with alternative unfired binders as lime replacement, compared to buildings made of standard LHC, and several conventional building materials. The assessment is based on ISO 14040, which deals with Life Cycle Assessment (LCA), and examines two aspects: energy, including pre-use phase Embodied Energy (EE), and use phase Operational Energy (OE); and CO2 emissions, including pre-use phase Embodied Carbon (EC), and use phase Operational Carbon (OC). The EE and EC calculations are based on published databases, while OE and OC were obtained with EnergyPlus simulations. The assessment refers to a specific case study in an arid region, with extreme diurnal and seasonal fluctuations of temperature and relative humidity. Using LHC with 100% unfired binder as lime replacement was shown to save up to 90% of the total energy consumption and CO2 emissions, as compared to conventional building materials. The findings of this research clearly demonstrate the high potential of LHC with unfired binders as lime replacement, which possesses the lowest energy requirements and CO2 emissions, illustrating the potential for a building with significantly low environmental impact over its life cycle, i.e., when calculating both EE and EC, and OE and OC.

Abstract Most research on the environmental sustainability of buildings often centers on reducing energy use and may overlook an equally crucial aspect of freshwater use. Buildings consume 1/5th of global fresh water in their construction as embodied water (EW) that must be reduced for long-term sustainability. Like embodied energy (EE), the EW of a facility is composed of a direct component used in construction processes and an indirect component that includes water used in manufacturing construction materials. An equally important component rarely covered in EW calculations is the energy-related embodied water (EREW), which comes from different energy sources that are consumed as EE, each of which depletes a significant amount of water in its generation, refinement, and transmission/transportation. This paper presents a macroeconomic model to compute and analyze not only the direct and indirect EW but also EREW of healthcare facilities. A wide variation is observed in calculated EW values associated with facilities’ initial construction (1,010-38,750 gallons/m²) and life cycle management (1,335-51,250 gallons/m²). The findings further show that EREW may represent 7.7% and 6% (average 6.7%) of the total EW of healthcare facilities relating to their initial construction and facilities management, respectively, including interior and exterior maintenance, repairs, and replacement activities. The significance of these findings is twofold. First, it shows that reducing EE may not help decrease most EW of a facility, and additional measures must be applied to decrease water use holistically. Second, it highlights the urgency of decreasing the water footprint of both renewable and non-renewable energy sources.

The role of the built environment and the construction industry in sustainable development gained global attention due to their significant share in global warming, GHG emissions, energy demand and depletion of non-renewable resources. Residential buildings carry the largest share amongst buildings and place heavy demands on natural resources for building materials, energy and water. The significant share of energy and natural resources involved in the production of building materials emphasizes the need for appropriate conservation strategies based on scientific study. This initiated efforts for comprehensive assessment of a building’s energy consumption and environmental impacts over its life span, termed as life cycle. Life Cycle Energy (LCE) in buildings comprises two major components, Embodied Energy (EE) and Operational Energy (OE). EE comprises the net energy involved in production of building materials, its transportation to the construction site, and construction. OE in buildings comprises energy required for occupant comfort and productivity which includes energy for lighting, heating, cooling and ventilation, normally excluding energy used for appliances (plug loads). While OE reflects the direct energy consumption in buildings, EE primarily comprises inherent capital energy associated with materials and building construction. Conventional approaches to energy conservation focus on OE as it affords some degree of active measures to regulate energy consumption. However, in addition to the EE already expended, the climatic-response of the specific building design and material used can have a significant bearing on the OE. Assessing the life-cycle energy of a building is thus complex. Moreover, EE assessment to support low-energy building design currently lack consensus on the methodology to be adopted. This is further exasperated by the lack of data on the energy involved in manufacture of building materials. The current study attempts to address these challenges by proposing and adopting a practical framework for EE assessment and generating data for prominent building materials in India based on first-hand data collection. The study reveals that a range of EE value for a building material is more practical to define, as a unique value does not hold good. This is attributed to the fact that the parameters determining EE of a material differ widely depending on the type of industrial process employed, its energy efficiency, geographical location, raw materials adopted, etc. Earlier studies on building energy conservation addressed only OE, as it generally carried a large share of the life cycle energy. But the fact that in some cases EE can outweigh OE of the building over its life, is gradually receiving attention. With improvements in OE efficiency of buildings, EE can constitute a greater share of the net life cycle energy. Lower the OE, higher the share of EE in LCE. Assessing relative share of EE and OE in buildings becomes a significant input to identify the potential areas for energy conservation. With this objective, the present study assessed EE and OE for few traditional and conventional dwellings in different climate zones of India using field survey data on building materials, construction technologies and OE etc. This study provides and insight into the energy in buildings with particular reference to the climatic-response associated with the thermal performance of traditional and modern buildings in India. The study reveals a wide range of EE value of rural and urban dwellings studied. The analysis for both rural and urban dwellings results did not reveal any definite correlation between EE and OE, and EE and LCE. However, the relative significance of EE and OE in LCE varied for urban dwellings depending on the climate zone. The results reiterate the importance of EE assessment for LCE analysis in buildings. Given available computational support, attempts are made to assess OE in buildings at the design stage itself adopting building simulation models. There has been extensive research since last few decades in developing various simulation tools for modeling building energy performance including that of air-conditioning, ventilation, lighting and other plug-loads. Building simulation studies facilitate OE analysis for various design alternatives keeping in mind low-energy performance. OE in buildings is greatly influenced by the local climate and the specific thermal characteristics of the building envelope. The thermal performance of the building envelope determines its ability to regulate indoor thermal comfort in response to external climatic conditions. To assess the thermal performance of building envelope, it is crucial to ascertain the thermal properties of constituent materials. Thermal conductivity, in addition to specific heat and density, is paramount to ascertain to understand thermal behavior, and also as crucial data to support OE building simulation studies. The present study includes experimental investigation on thermal properties of different envelope materials, to generate input data for building simulation studies. An ideal building envelope would passively regulate indoor thermal comfort through the year, so as to place no demand on OE to maintain thermal comfort. Building simulation studies enable proper designs for suitable thermal performance of building envelope to achieve minimum OE. In this perspective, the present study includes building modeling and simulation study of traditional and conventional dwelling for their influence on OE. One of the objectives of this section of the study is to understand the intricacies involved in building modeling and simulation. The study examines OE in traditional and conventional dwellings for various wall materials in different climate zones. The results reveal variations in OE for various climatic conditions, but limited variation for different walling materials. In the traditional dwelling, natural ventilation was found to play a dominant role in regulating indoor thermal comfort while in the conventional dwelling thermal performance of the fenestration (glazing) strongly influenced indoor thermal comfort. Thus, the present work links studies on energy in buildings and associated aspects of building materials in a systematic manner to present a comprehensive research study.

AbstractThe paper proposes considerations stemming from the analysis of twenty-two buildings that show different approaches to ‘vegetarian architecture’—a theoretical stance based on principles learnt from agriculture and nutrition. The first phase consisted in a systematic investigation of the constructional characteristics of each building, and the cataloguing of their components. The ‘cradle to gate’ embodied energy (EE) and ‘embodied carbon’ (EC) were then calculated, based on two open access databases: ICE and Ökobaudat. The applicability of these databases was considered, as they do not cover low industrialised bio-based construction materials. For some materials, data are missing; while in others, EE values are overestimated since high energy-intensive manufacturing processes seem to be assumed. In a second phase, the uses and production process of some non-conventional materials was investigated, evidencing their variability. Building technologies that are not just aimed at low operational energy but at a more holistic understanding of low environmental impact represent a paradigm shift in ‘sustainable’ construction practices. Despite ongoing actions and policies, as long as these materials and techniques are not suitably represented in reliable and accessible databases, it will be difficult to make such a shift happen. Manufacturers and contractors who produce and use such materials would benefit from the availability of easily applicable, scientific data demonstrating environmental advantages offered by non-conventional materials.