scholarly journals Benchmarks for Embodied and Operational Energy Assessment of Hellenic Single-Family Houses

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4384
Author(s):  
Elena G. Dascalaki ◽  
Poulia A. Argiropoulou ◽  
Constantinos A. Balaras ◽  
Kalliopi G. Droutsa ◽  
Simon Kontoyiannidis
Keyword(s):  
Energy Use ◽  
Energy Intensity ◽  
Construction Materials ◽  
Energy Performance ◽  
Embodied Energy ◽  
Single Family ◽  
Zero Energy ◽  
Relative Significance ◽  
Climate Conditions ◽  
Operational Energy

Building energy performance benchmarking increases awareness and enables stakeholders to make better informed decisions for designing, operating, and renovating sustainable buildings. In the era of nearly zero energy buildings, the embodied energy along with operational energy use are essential for evaluating the environmental impacts and building performance throughout their lifecycle. Key metrics and baselines for the embodied energy intensity in representative Hellenic houses are presented in this paper. The method is set up to progressively cover all types of buildings. The lifecycle analysis was performed using the well-established SimaPro software package and the EcoInvent lifecycle inventory database, complemented with national data from short energy audits carried out in Greece. The operational energy intensity was estimated using the national calculation engine for assessing the building’s energy performance and the predictions were adapted to obtain more realistic estimates. The sensitivity analysis for different type of buildings considered 16 case studies, accounting for representative construction practices, locations (climate conditions), system efficiencies, renovation practices, and lifetime of buildings. The results were used to quantify the relative significance of operational and embodied energy, and to estimate the energy recovery time for popular energy conservation and energy efficiency measures. The derived indicators reaffirm the importance of embodied energy in construction materials and systems for new high performing buildings and for renovating existing buildings to nearly zero energy.

Zero Energy Houses and Embodied Energy: Regulatory and Design Considerations

2008 ◽  
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.

scholarly journals Strategies to Improve the Energy Performance of Buildings: A Review of Their Life Cycle Impact

Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  
Keyword(s):  
Life Cycle ◽  
Case Studies ◽  
Environmental Impacts ◽  
Energy Use ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Environmental Benefits ◽  
Embodied Energy ◽  
Trade Offs ◽  
Operational Energy

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.

scholarly journals Analysing energy upgrading projects of single-family houses towards a Norwegian nZEB level

2021 ◽  
Vol 2069 (1) ◽  
pp. 012112
Author(s):  
R Moschetti ◽  
B Time ◽  
L Gullbrekken ◽  
V Heide ◽  
L Georges ◽  
...  
Keyword(s):  
Energy Use ◽  
Thermal Environment ◽  
Energy Performance ◽  
High Energy ◽  
Building Envelope ◽  
Interdisciplinary Teams ◽  
Single Family ◽  
Zero Energy ◽  
Use Of Resources ◽  
Definition Of

Abstract As the existing building stock is responsible for high energy use and greenhouse gas emissions, energy upgrading projects have been acknowledged as crucial for the energy performance improvement of existing buildings, as well as for environment preservation and rational use of resources. The aim of this article is to investigate the definition of a nearly zero-energy building (nZEB) level for the energy upgrading of single-family houses. In particular, the findings from a research project, i.e., “energy upgrading of wooden dwellings to nearly zero energy level” (OPPTRE), are presented and discussed. A core task of OPPTRE was to carry out an architectural competition, where six interdisciplinary teams proposed innovative solutions for upgrading to a nZEB level representative Norwegian wooden single-family houses, from the period 1950-1990. The upgrading measures proposed in the OPPTRE competition focused on several aspects, such as architectural quality, indoor thermal environment, energy use/generation, carbon footprint, and cost effectiveness. General principles for a nZEB level achievement in upgrading projects are discussed in this article, as deducted from the evaluation of the results of the OPPTRE architectural competition. In particular, the focus is on examining the solutions proposed for upgrading building envelope and technical building systems. Energy use, energy generation, investment costs, and CO2 emissions are examined across the various OPPTRE projects, striving to define a trade-off among different parameters for the achievement of a nZEB level. The findings of this paper support the creation of knowledge in nearly zero-energy upgrading of wooden single-family houses, aiming to a more systematic definition of a nZEB level in such projects. This can be relevant for several stakeholders, such as governmental institutions, homeowners, builders, and private or public decision makers, towards the market uptake of nZEB upgrading by 2030.

scholarly journals Embodied Energy versus Operational Energy. Showing the Shortcomings of the Energy Performance Building Directive (EPBD)

2012 ◽  
Vol 730-732 ◽  
pp. 587-591 ◽  
Author(s):  
F. Pacheco-Torgal ◽  
Joana Faria ◽  
Saíd Jalali
Keyword(s):  
Power Plants ◽  
Building Materials ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Hot Water ◽  
Embodied Energy ◽  
Mineral Admixtures ◽  
High Efficient ◽  
Operational Energy

Energy is a key issue for Portugal, it is responsible for the higher part of its imports and since almost 30% of Portuguese energy is generated in power stations it is also responsible for high CO2 emissions. Between 1995 and 2005 Portuguese GNP rise 28%, however the imported energy in the same period increased 400%, from 1500 million to 5500 million dollars. As to the period between 2005 and 2007 the energy imports reach about 10,000 million dollars. Although recent and strong investments in renewable energy, Portugal continue to import energy and fossil fuels. This question is very relevant since a major part of the energy produced in Portugal is generated in power plants thus emitting greenhouse gases (GHGs). Therefore, investigations that could minimize energy use are needed. This paper presents a case study of a 97 apartment-type building (27.647 m2) located in Portugal, concerning both embodied energy as well as operational energy (heating, hot water, electricity). The operational energy was an average of 187,2 MJ/m2/yr and the embodied energy accounts for aprox. 2372 MJ/m2, representing just 25,3% of the former for a service life of 50 years. Since Portuguese energy efficiency building regulation made under the Energy Performance Building Directive (2002/91/EC-EPBD) will lead to a major decrease of operational energy this means that the energy required for the manufacturing of building materials could represent in a near future almost 400% of operational energy. Replacement up to 75% of Portland cement with mineral admixtures could allow energy savings needed to operate a very high efficient 97 apartment-type building during 50 years.

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

2021 ◽  
Author(s):  
◽  
Dekhani Juvenalis Dukakis Nsaliwa
Keyword(s):  
Energy Demand ◽  
Energy Use ◽  
Residential Buildings ◽  
Embodied Energy ◽  
Energy Requirements ◽  
Zero Energy ◽  
Multi Scale ◽  
Energy Demands ◽  
Zero Energy Building ◽  
Operational Energy

<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>

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

2021 ◽  
Author(s):  
◽  
Dekhani Juvenalis Dukakis Nsaliwa
Keyword(s):  
Energy Demand ◽  
Energy Use ◽  
Residential Buildings ◽  
Embodied Energy ◽  
Energy Requirements ◽  
Zero Energy ◽  
Multi Scale ◽  
Energy Demands ◽  
Zero Energy Building ◽  
Operational Energy

<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>

scholarly journals Operating energy demand of various residential building typologies in different European climates

2018 ◽  
Vol 7 (3/4) ◽  
pp. 226-250 ◽  
Author(s):  
Brian Cody ◽  
Wolfgang Loeschnig ◽  
Alexander Eberl
Keyword(s):  
Energy Demand ◽  
Energy Production ◽  
Energy Performance ◽  
Electricity Production ◽  
Single Family ◽  
Content Type ◽  
Climate Conditions ◽  
Apartment Buildings ◽  
Operational Energy ◽  
Family Home

Purpose The work described below compares three very different residential typologies in terms of their energy performance in operation. The purpose of this paper is to identify the influence of building typologies and corresponding urban morphologies on operational energy demand and the potential for building integrated energy production. Design/methodology/approach Two of the typologies studied are apartment buildings while the third comprises single-family homes located on small plots. An important factor under consideration is the insertion into the respective urban design configuration so that mutual shading of the buildings and the ensuing impact on energy performance is evaluated. Heating and cooling demands, as well as the potential for building-integrated electricity production were investigated for four different European climates in a dynamic thermal simulation environment. Findings The results show that the investigated apartment buildings have a lower operational energy demand than the single-family home in all climates. This advantage is most pronounced in cool climate conditions. At the same time the investigated single-family home has the highest potential for building integrated renewable energy production in all climates. This advantage is most pronounced in low latitudes. Originality/value The study builds up on generic buildings that are based on a common urban grid and are easily comparable and scalable into whole city districts. Still, these buildings are planned into such detail, that they provide fully functional floor plans and comply with national building regulations. This approach allows us to draw conclusions on the scale of individual buildings and at an urban scale at the same time.

scholarly journals UNDERSTANDING THE EMBEDDED CARBON CHALLENGES OF BUILDING SERVICE SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 3279-3288
Author(s):  
Maria Hein ◽  
Darren Anthony Jones ◽  
Claudia Margot Eckert
Keyword(s):  
Energy Use ◽  
Cooling System ◽  
Current System ◽  
Energy Performance ◽  
Service Systems ◽  
Carbon Footprints ◽  
Embodied Carbon ◽  
Study Results ◽  
Operational Energy

AbstractEnergy consumed in buildings is a main contributor to CO2 emissions, there is therefore a need to improve the energy performance of buildings, particularly commercial buildings whereby building service systems are often substantially over-designed due to the application of excess margins during the design process.The cooling system of an NHS Hospital was studied and modelled in order to identify if the system was overdesigned, and to quantify the oversizing impact on the system operational and embodied carbon footprints. Looking at the operational energy use and environmental performance of the current system as well as an alternative optimised system through appropriate modelling and calculation, the case study results indicate significant environmental impacts are caused by the oversizing of cooling system.The study also established that it is currently more difficult to obtain an estimate of the embodied carbon footprint of building service systems. It is therefore the responsibility of the machine builders to provide information and data relating to the embodied carbon of their products, which in the longer term, this is likely to become a standard industry requirement.

CITIES, ENERGY AND CLIMATE: SEVEN REASONS TO QUESTION THE DENSE HIGH-RISE CITY

2020 ◽  
Vol 15 (3) ◽  
pp. 197-214
Author(s):  
Chris Butters ◽  
Ali Cheshmehzangi ◽  
Paola Sassi
Keyword(s):  
Land Use ◽  
Energy Supply ◽  
Energy Use ◽  
Green Space ◽  
Embodied Energy ◽  
Heat Island ◽  
Medium Density ◽  
Ongoing Research ◽  
High Rise ◽  
Operational Energy

ABSTRACT Dense high-rise cities offer some advantages in terms of sustainability but have considerable downsides. Low-dense and medium-rise typologies have been shown to offer good social qualities; their potential energy and carbon advantages have received less attention. As the energy consumption, emissions of cities and heat island effects increase; we question whether dense, high-rise cities offer optimal sustainability. We discuss seven areas where medium density and lower rise typologies offer advantages in terms of energy and climate including: land use/density; microclimate/green space; energy supply; transports; operational energy/carbon; embodied energy/carbon; and resilience. The aim is to discuss the cumulative importance of these areas in the context of sustainable energy use and climate emissions. These areas are subject to ongoing research and are only discussed briefly, since the overarching synthesis perspective for urban planning is our focus. The picture that emerges when these points are seen together, suggests that medium density and lower rise options—like traditional European typologies—may offer, in addition to social qualities, very significant advantages in terms of energy, carbon and climate emissions.

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

2018 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
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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