Zero Energy Houses and Embodied Energy: Regulatory and Design Considerations

Author(s):  
Patxi Hernandez ◽  
Paul Kenny

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.

2013 ◽  
Vol 4 (2) ◽  
pp. 163-169
Author(s):  
Zs. Szalay ◽  
T. Csoknyai

Abstract The recast of the Energy Performance Building Directive contains a new article about the need to increase the number of buildings which go beyond current national requirements, and to draw up national plans for increasing the number of nearly zero-energy buildings (nZEB) with the final target that by 2020 all new buildings shall be nearly-zero energy. Nearly zero-energy buildings are buildings with a very high energy performance, where the remaining low energy demand can be supplied to a significant extent by renewable energy. In this paper, a detached house complying with the proposed Hungarian nZEB requirements is analysed. The life cycle cost and life cycle environmental impacts of the building are assessed for various building service systems to optimise the building design.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4384
Author(s):  
Elena G. Dascalaki ◽  
Poulia A. Argiropoulou ◽  
Constantinos A. Balaras ◽  
Kalliopi G. Droutsa ◽  
Simon Kontoyiannidis

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.


2019 ◽  
Vol 887 ◽  
pp. 335-343
Author(s):  
Nazanin Moazzen ◽  
Mustafa Erkan Karaguler ◽  
Touraj Ashrafian

Energy efficiency has become a crucial part of human life, which has an adverse impact on the social and economic development of any country. In Turkey, it is a critical issue especially in the construction sector due to increase in the dependency on the fuel demands. The energy consumption, which is used during the life cycle of a building, is a huge amount affected by the energy demand for material and building construction, HVAC and lighting systems, maintenance, equipment, and demolition. In general, the Life Cycle Energy (LCE) needs of the building can be summarised as the operational and embodied energy together with the energy use for demolition and recycling processes.Besides, schools alone are responsible for about 15% of the total energy consumption of the commercial building sector. To reduce the energy use and CO2 emission, the operational and embodied energy of the buildings must be minimised. Overall, it seems that choosing proper architectural measures for the envelope and using low emitting material can be a logical step for reducing operational and embodied energy consumptions.This paper is concentrated on the operating and embodied energy consumptions resulting from the application of different architectural measures through the building envelope. It proposes an educational building with low CO2 emission and proper energy performance in Turkey. To illustrate the method of the approach, this contribution illustrates a case study, which was performed on a representative schoold building in Istanbul, Turkey. Energy used for HVAC and lighting in the operating phase and the energy used for the manufacture of the materials are the most significant parts of embodied energy in the LCE analyses. This case study building’s primary energy consumption was calculated with the help of dynamic simulation tools, EnergyPlus and DesignBuilder. Then, different architectural energy efficiency measures were applied to the envelope of the case study building. Then, the influence of proposed actions on LCE consumption and Life Cycle CO2 (LCCO2) emissions were assessed according to the Life Cycle Assessment (LCA) method.


Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  

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.


2020 ◽  
Vol 12 (1) ◽  
pp. 351 ◽  
Author(s):  
Hossein Omrany ◽  
Veronica Soebarto ◽  
Ehsan Sharifi ◽  
Ali Soltani

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.


2021 ◽  
Vol 65 (2-4) ◽  
pp. 312-316
Author(s):  
Surnam Sonia Longo ◽  
Maurizio Cellura ◽  
Maria Anna Cusenza ◽  
Francesco Guarino ◽  
Ilaria Marotta

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.


2019 ◽  
Vol 9 (11) ◽  
pp. 2261 ◽  
Author(s):  
Maria Ferrara ◽  
Federico Prunotto ◽  
Andrea Rolfo ◽  
Enrico Fabrizio

The effective design of nearly zero-energy buildings depends on a large set of interdependent variables, which affect both energy demand and supply. Considering them simultaneously is fundamental when searching for optimal design of nearly zero-energy buildings, as encouraged by the EU in the second recast of the Energy Performance of Building Directive (EPBD). This paper presents the application of the new energy demand and supply simultaneous optimization (EDeSSOpt) methodology to optimize the design of a single-family house in the Italian context. Both primary energy optimization and financial optimization are carried out in the context of European regulations. Robustness of the resulting optimal solution is studied through analysis of optimum neighborhoods. The resulting cost-optimized solution relies on a moderately insulated envelope, a highly efficient system, and 34% of coverage from renewables. The energy-optimized solution requires a higher level of insulation and a higher coverage from renewables, demonstrating that there is still a gap between energy and cost optimums. Beyond the results, integrated optimization by means of EDeSSOpt is demonstrated to better minimize cost functions while improving the robustness of results.


2016 ◽  
Vol 841 ◽  
pp. 110-115
Author(s):  
Gheorge Badea ◽  
Raluca Andreea Felseghi ◽  
Simona Răboaca ◽  
Ioan Aşchilean ◽  
Andrei Bolboacă ◽  
...  

For a good approach to new challenges recommended by EU Energy Performance of Buildings Directive, nearly Zero Energy Buildings (nZEB) concept for new residential buildings is conceived in order to drastically improving the overall performance of classical buildings, especially in terms of energy use, production and CO2 equivalent (CO2e) emissions. This paper shows the results of the case study where was investigated energy, economic and environmental performances of hybrid solar and wind system for neutral in terms of climate parameters nZEB. The aim of this study was to demonstrate the capability and feasibility of RES hybrid technology for the energy supply of Romanian nZEB, and also, was to establish new general criteria with the goal to determinate the optimal design solution and providing general principles for green energy production. The main results reveal that Romania has a potential for green energy to implement the new concept nZEB and the global technical optimum of a hybrid system for nZEB is determined by the optimal interaction between the design parameters. The hybrid solar and wind electric systems are functioned in operational stand alone mode, its are supplied 100% by energy from RES and embedded CO2 emissions are decreased by over 50% compared to the classics systems.


2014 ◽  
Vol 1020 ◽  
pp. 561-565 ◽  
Author(s):  
Rastislav Ingeli ◽  
Katarína Minarovičová ◽  
Miroslav Čekon

Buildings account for 40% of the primary energy use and 24%of the generation of green house gases worldwide. Therefore, a reduction of the specific energy demand of buildings and increased use of renewable energy are important measures of climate change mitigation. On the 18th of May 2010 a recast of the EPBD was approved which further clarifies the intention that buildings shall have a low energy demand. The recast of the EPBD specifies that by the end of 2020 all new buildings shall be “nearly zero-energy buildings”. A nearly zero-energy building is defined as a building with a very high energy performance and very simple shape. The current focusing on the energy efficiency of the building operation may lead to uniform cuboid architecture with heavy insulated building envelopes. The paper deals with the influence of energy concept on architectural elements (and their properties as shape, material, colour, texture etc.)


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