Energy performance of an exhibition hall in a life cycle perspective: embodied energy, operational energy and retrofit strategies

Globally, the building sector is responsible for more than 40% of energy use and it contributes approximately 30% of the global Greenhouse Gas (GHG) emissions. This high contribution stimulates research and policies to reduce the operational energy use and related GHG emissions of buildings. However, the environmental impacts of buildings can extend wide beyond the operational phase, and the portion of impacts related to the embodied energy of the building becomes relatively more important in low energy buildings. Therefore, the goal of the research is gaining insights into the environmental impacts of various building strategies for energy efficiency requirements compared to the life cycle environmental impacts of the whole building. The goal is to detect and investigate existing trade-offs in current approaches and solutions proposed by the research community. A literature review is driven by six fundamental and specific research questions (RQs), and performed based on two main tasks: (i) selection of literature studies, and (ii) critical analysis of the selected studies in line with the RQs. A final sample of 59 papers and 178 case studies has been collected, and key criteria are systematically analysed in a matrix. The study reveals that the high heterogeneity of the case studies makes it difficult to compare these in a straightforward way, but it allows to provide an overview of current methodological challenges and research gaps. Furthermore, the most complete studies provide valuable insights in the environmental benefits of the identified energy performance strategies over the building life cycle, but also shows the risk of burden shifting if only operational energy use is focused on, or when a limited number of environmental impact categories are assessed.

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Beyond Operational Energy Efficiency: A Balanced Sustainability Index from a Life Cycle Consideration

Sustainability ◽

10.3390/su132011263 ◽

2021 ◽

Vol 13 (20) ◽

pp. 11263

Author(s):

Ming Hu

Keyword(s):

Life Cycle ◽

Energy Savings ◽

Operating Cost ◽

Embodied Energy ◽

Emissions Reduction ◽

Sustainability Index ◽

Trade Offs ◽

Life Cycle Perspective ◽

Operational Energy ◽

Whole Life Cycle

Most deep energy renovation projects focus only on an operating energy reduction and disregard the added embodied energy derived from adding insulation, window/door replacement, and mechanical system replacement or upgrades. It is important to study and address the balance and trade-offs between reduced operating energy and added embodied energy from a whole life cycle perspective to reduce the overall building carbon footprint. However, the added embodied energy and related environmental impact have not been studied extensively. In response to this need, this paper proposes a holistic sustainability index that balances the trade-off between reduced operating energy and added embodied energy. Eight case projects are used to validate the proposed method and calculation. The findings demonstrate that using a balanced sustainability index can reveal results different from a conventional operating energy-centric approach: (a) operating energy savings can be offset by the embodied energy gain, (b) the operating energy savings do not always result in a life cycle emissions reduction, and (c) the sustainability index can vary depending on the priorities the decision makers give to operating carbon, embodied carbon, and operating cost. Overall, the proposed sustainability score can provide us with a more comprehensive understanding of how sustainable the renovation works are from a life cycle carbon emissions perspective, providing a more robust estimation of global warming potential related to building renovation.

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Environmental analysis and a suggestion for assessment of detached houses

International Review of Applied Sciences and Engineering ◽

10.1556/irase.4.2013.2.8 ◽

2013 ◽

Vol 4 (2) ◽

pp. 143-149

Author(s):

K. Minarovičová ◽

R. Rabenseifer

Keyword(s):

Life Cycle ◽

Environmental Analysis ◽

Final Section ◽

Energy Performance ◽

Embodied Energy ◽

Building Performance ◽

Performance Simulation ◽

Building Performance Simulation ◽

Operational Energy ◽

Detached House

Abstract The article presents environmental analysis of a detached house in terms of its life cycle. The analysis is simplified in order to compare the built and operational energy of the building whereas the operational energy is described using computer aided building performance simulation. The input data related to the built (embodied) energy are based on information from classical works on life cycle analysis. The article also justifies the simplification of environmental analysis, which aims to build pragmatically on existing standardization and legislation on energy performance of buildings. The final section provides some considerations concerning the environmental assessment of buildings.

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The applicability of different energy performance calculation methods for building life cycle environmental optimization

International Review of Applied Sciences and Engineering ◽

10.1556/1848.2018.9.2.6 ◽

2018 ◽

Vol 9 (2) ◽

pp. 115-121 ◽

Cited By ~ 2

Author(s):

B. Kiss ◽

ZS. Szalay

Keyword(s):

Life Cycle ◽

Energy Use ◽

Energy Performance ◽

Computational Time ◽

Calculation Methods ◽

Apartment House ◽

Building Stock ◽

Operational Energy ◽

Time Accuracy ◽

Building Life Cycle

Building life cycle assessment is getting more and more attention within the topic of environmental impact caused by the built environment. Although more and more research focus on the embodied impact of buildings, the investigation of the operational energy use still needs attention. The majority of the building stock still does not comply with the nearly zero energy requirements. Also, in case of retrofitting, when most of the embodied impact is already spent on the existing structures (and so immutable), the importance of the operational energy rises. There are several methods to calculate the energy performance of buildings covering the range from simplified seasonal methods to detailed hourly energy simulations. Not only the accuracy of the calculations, but the computational time can be significantly different within the methods. The latter is especially important in case of optimization, when there is limited time to perform one calculation. Our research shows that the use of different calculation techniques can lead to different optima for environmental impacts in case of retrofitting. In this paper we compare these calculation methods with focus on computational time, accuracy and applicability to environmental optimization of buildings. We present the results in a case study of the retrofitting of a middle-sized apartment house in Hungary.

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Application of Life Cycle Energy Assessment in Residential Buildings: A Critical Review of Recent Trends

Sustainability ◽

10.3390/su12010351 ◽

2020 ◽

Vol 12 (1) ◽

pp. 351 ◽

Cited By ~ 3

Author(s):

Hossein Omrany ◽

Veronica Soebarto ◽

Ehsan Sharifi ◽

Ali Soltani

Keyword(s):

Life Cycle ◽

Energy Consumption ◽

Energy Use ◽

Residential Buildings ◽

Current Trend ◽

Energy Performance ◽

Embodied Energy ◽

System Boundary ◽

Energy Assessment ◽

Boundary Definition

Residential buildings are responsible for a considerable portion of energy consumption and greenhouse gas emissions worldwide. Correspondingly, many attempts have been made across the world to minimize energy consumption in this sector via regulations and building codes. The focus of these regulations has mainly been on reducing operational energy use, whereas the impacts of buildings’ embodied energy are frequently excluded. In recent years, there has been a growing interest in analyzing the energy performance of buildings via a life cycle energy assessment (LCEA) approach. The increasing amount of research has however caused the issue of a variation in results presented by LCEA studies, in which apparently similar case studies exhibited different results. This paper aims to identify the main sources of variation in LCEA studies by critically analyzing 26 studies representing 86 cases in 12 countries. The findings indicate that the current trend of LCEA application in residential buildings suffers from significant inaccuracy accruing from incomplete definitions of the system boundary, in tandem with the lack of consensus on measurements of operational and embodied energies. The findings call for a comprehensive framework through which system boundary definition for calculations of embodied and operational energies can be standardized.

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The Life-Cycle Energy Consumption Distribution of Buildings in China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1008-1009.1320 ◽

2014 ◽

Vol 1008-1009 ◽

pp. 1320-1325

Author(s):

Zhao Dong Li ◽

Yu Rong Yao ◽

Geng Dai ◽

Yi Chu Ding

Keyword(s):

Life Cycle ◽

Energy Consumption ◽

Energy Distribution ◽

Building Materials ◽

Policy Formulation ◽

Embodied Energy ◽

Practical Significance ◽

Operational Energy ◽

Materials Recycling ◽

Material Energy

In recent years, continues development of China urbanization gradually increases the energy consumption of buildings. Studies on the life cycle energy distribution of buildings have practical significance to determine energy policy formulation and adjustment. Based on previous studies and the composition of the life cycle energy consumption of buildings, this article constructed a life-cycle energy consumption model, and established the calculation methods of initial embodied energy, operational energy, reset embodied energy ,dismantle embodied energy and recycle embodied energy separately. Based on ICE material energy data and combined rating per machine per team, this article calculated the life cycle energy distribution of a building in Nanjing. We found that the life cycle energy of buildings obeyed normal distribution, the operational energy accounts for a large proportion and it decreases with the decreased life cycle of buildings. The recovery of operational energy can reduce the proportion of the initial embodied energy. Considering the studies, in order to meet the characteristic of the buildings in China which have short life cycle, we should focus on the development of building materials recycling and reusing.

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Selecting Insulating Materials for Building Envelope: A Life Cycle Approach

TECNICA ITALIANA-Italian Journal of Engineering Science ◽

10.18280/ti-ijes.652-426 ◽

2021 ◽

Vol 65 (2-4) ◽

pp. 312-316

Author(s):

Surnam Sonia Longo ◽

Maurizio Cellura ◽

Maria Anna Cusenza ◽

Francesco Guarino ◽

Ilaria Marotta

Keyword(s):

Life Cycle ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Cellulose Fibers ◽

Energy Performance ◽

Embodied Energy ◽

Life Cycle Approach ◽

Insulation Material ◽

Gas Emissions ◽

Building Envelopes

This paper aims at assessing the embodied energy and greenhouse gas emissions (GHGs) of two building envelopes, designed for a two floors semi-detached house located in the Central Italy. The analysis is performed by applying the Life Cycle Assessment methodology, following a from cradle-to-gate approach. Fixtures (windows and doors), external and internal opaque walls, roof and floors (including interstorey floors) make the building envelopes. Their stratigraphy allows for achieving the thermal transmittance values established in the Italian Decree on energy performance of buildings. The two examined envelopes differ only for the insulation material: extruded expanded polystyrene (XPS) or cellulose fibers. The results shows that the envelope using cellulose fibers has better performance than that using XPS: it allows for reducing the embodied energy and the GHGs of about 13% and 9.3%, respectively. A dominance analysis allows to identify the envelope components responsible of the higher impacts and the contribution of the insulating material to the impacts. The study is part of the Italian research “Analysis of the energy impacts and greenhouse gas emissions of technologies and components for the energy efficiency of buildings from a life cycle perspective” funded by the Three-year Research Plan within the National Electricity System 2019-2021.

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Environmental Performance Measures to Assess Building Refurbishment from a Life Cycle Perspective

Energies ◽

10.3390/en12020299 ◽

2019 ◽

Vol 12 (2) ◽

pp. 299 ◽

Cited By ~ 4

Author(s):

Helena Nydahl ◽

Staffan Andersson ◽

Anders Åstrand ◽

Thomas Olofsson

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Environmental Performance ◽

Ghg Emissions ◽

Assessment Method ◽

The European Union ◽

Building Stock ◽

Life Cycle Perspective ◽

Building Refurbishment ◽

Operational Energy

Energy efficiency investments in existing buildings are an effective way of reducing the environmental impact of the building stock. Even though policies in the European Union and elsewhere promote a unilateral focus on operational energy reduction, scientific studies highlight the importance of applying a life cycle perspective to energy refurbishment. However, life cycle assessment is often perceived as being complicated and the results difficult to interpret by the construction sector. There is also a lack of guidelines regarding the sustainable ratio between the embodied and accumulated operational impact. The scope of this study is to introduce a life cycle assessment method for building refurbishment that utilizes familiar economic performance tools, namely return on investment and annual yield. The aim is to use the introduced method to analyze a case building with a sustainability profile. The building was refurbished in order to reduce its operational energy use. The introduced method is compatible with a theory of minimum sustainable environmental performance that may be developed through backcasting from defined energy and GHG emissions objectives. The proposed approach will hopefully allow development of sustainable refurbishment objectives that can support the choice of refurbishment investments.

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The importance of embodied energy in carbon footprint assessment

Structural Survey ◽

10.1108/ss-01-2013-0012 ◽

2014 ◽

Vol 32 (1) ◽

pp. 49-60 ◽

Cited By ~ 31

Author(s):

Zaid Alwan ◽

Paul Jones

Keyword(s):

Life Cycle ◽

Carbon Footprint ◽

Embodied Energy ◽

Total Carbon ◽

Design Team ◽

Content Type ◽

Operational Energy ◽

The Impact ◽

Whole Life Cycle

Purpose – 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. Design/methodology/approach – 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. Findings – 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. Research limitations/implications – 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. Originality/value – 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.

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Zero Energy Houses and Embodied Energy: Regulatory and Design Considerations

ASME 2008 2nd International Conference on Energy Sustainability, Volume 2 ◽

10.1115/es2008-54290 ◽

2008 ◽

Cited By ~ 3

Author(s):

Patxi Hernandez ◽

Paul Kenny

Keyword(s):

Life Cycle ◽

Energy Demand ◽

Energy Use ◽

Construction Materials ◽

Energy Performance ◽

Embodied Energy ◽

Base Case ◽

Life Cycle Approach ◽

Zero Energy ◽

Zero Energy Buildings

Building energy performance regulations and standards around the world are evolving aiming to reduce the energy use in buildings. As we move towards zero energy buildings, the embodied energy of construction materials and energy systems becomes more important, as it represents a high percentage of the overall life cycle energy use of a building. However, this issue is still ignored by many regulations and certification methods, as happens with the European Energy Performance of Buildings Directive (EPBD), which focuses on the energy used in operation. This paper analyses a typical house designed to comply with Irish building regulations, calculating its energy use for heating and how water with the Irish national calculation tool, which uses a methodology in line with the EPBD. A range of measures to reduce the energy performance in use of this typical house are proposed, calculating the reduced energy demand and moving towards a zero energy demand building. A life-cycle approach is added to the analysis, taking into account the differential embodied energy of the implemented measures in relation to the typical house base-case, annualizing the differential embodied energy and re-calculating the overall energy use. The paper discusses how a simplified approach for accounting embodied energy of materials could be useful in a goal to achieve the lowest life-cycle energy use in buildings, and concludes with a note on how accounting for embodied energy is a key element when moving towards zero energy buildings.

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