scholarly journals In search of optimal consumption: A review of causes and solutions to the energy performance gap in residential buildings

2021 ◽  
pp. 111253
Author(s):  
Stefano Cozza ◽  
Jonathan Chambers ◽  
Arianna Brambilla ◽  
Martin K. Patel
Keyword(s):  
Residential Buildings ◽  
Energy Performance ◽  
Optimal Consumption ◽  
Performance Gap

scholarly journals Examining the performance gap in LEED certified murbs

2021 ◽  
Author(s):  
Kaitlin Paige Carroll
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Performance Outcomes ◽  
Design Stage ◽  
Contributing Factors ◽  
Performance Gap ◽  
Greater Toronto Area ◽  
Energy Modelling

This study assesses the performance gap between actual energy performance and desired energy performance outcomes for a case study of 19 LEED-certified multi-unit residential buildings in the Greater Toronto Area. The study examines 1) how accurately design-stage energy modelling predicts actual energy use, 2) how much variation of energy performance can be seen between buildings of the same level of certification, and 3) the key contributing factors of this performance gap. Using EUI as the basis of comparison, trend analysis was carried out. It was determined that a performance gap between modelled and actual building energy use does exist. When compared to a larger sample of existing buildings, the case study buildings show no real improvement, on average. Regression models revealed no strong correlation between LEED Level or LEED EAc1 credits and reduced EUIs.

Measuring the thermal energy performance gap of labelled residential buildings in Switzerland

Energy Policy ◽  
2020 ◽  
Vol 137 ◽  
pp. 111085 ◽  
Author(s):  
Stefano Cozza ◽  
Jonathan Chambers ◽  
Martin K. Patel
Keyword(s):  
Thermal Energy ◽  
Residential Buildings ◽  
Energy Performance ◽  
Performance Gap

scholarly journals Energy Performance Gap Analysis in Energy Efficient Residential Buildings in Lithuania

2021 ◽  
Vol 25 (1) ◽  
pp. 610-620
Author(s):  
Violeta Motuzienė ◽  
Vilūnė Lapinskienė ◽  
Genrika Rynkun ◽  
Jonas Bielskus
Keyword(s):  
Energy Demand ◽  
High Performance ◽  
Gap Analysis ◽  
Residential Buildings ◽  
Energy Performance ◽  
High Energy ◽  
Positive Energy ◽  
Performance Gap ◽  
Class A ◽  
Very High Energy

Abstract Implementing provisions of the EPBD all Member States require to provide EPC (Energy Performance Certificate) when buildings are c onstructed, sold or rented. The purpose of the certificate is to compare buildings’ performance and inform the end-users. However, quite many mismatches and discrepancies could be found when comparing actual energy consumption with the once declared by the EPC. This mismatch of energy demand is known as Energy Performance Gap (EPG). It was analysed by different researchers on national levels. In the study, an overall overview of the high-performance buildings in Lithuania is performed and EPG is analysed using statistical indicators. Analysis has shown that for class A the EPG varies from −101 % to +77 %. More buildings are found to have a positive Energy Performance Gap. For class A+ and A++ variations are within a narrower interval: from +18 to 76 % and from +23 to 77 % accordingly. It confirms the findings in the other countries that very high-energy performance buildings tend to consume more than predicted. Also it is confirmed that despite differences in national certification methodologies, the same problem (just of different scale) exists and EPC schemes need revisions.

scholarly journals The Energy Performance Gap in Swiss residential buildings: a roadmap for improvement

2021 ◽  
Vol 2042 (1) ◽  
pp. 012143
Author(s):  
Stefano Cozza ◽  
Jonathan Chambers ◽  
Martin K. Patel
Keyword(s):  
Energy Consumption ◽  
Residential Buildings ◽  
Qualitative Interviews ◽  
Energy Performance ◽  
Extensive Literature ◽  
Existing Buildings ◽  
Accurate Calculation ◽  
Performance Gap ◽  
The Difference ◽  
Theoretical Energy Consumption

Abstract This work deals with the Energy Performance Gap (EPG) in buildings, defined as the difference between actual and theoretical energy consumption. This paper investigates how to close the EPG of existing buildings in Switzerland, by which measures, until when, and at which costs. To address these questions an extensive literature review was conducted combined with qualitative interviews in order to better understand practitioners’ experience and to support the findings from the literature. Several approaches have been found to reduce the EPG. These include both measures to make the building consume as expected and to arrive at a more accurate calculation of the theoretical consumption. We highlight the most relevant solutions for the Swiss context.

scholarly journals Examining the performance gap in LEED certified murbs

2021 ◽  
Author(s):  
Kaitlin Paige Carroll
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Performance Outcomes ◽  
Design Stage ◽  
Contributing Factors ◽  
Performance Gap ◽  
Greater Toronto Area ◽  
Energy Modelling

This study assesses the performance gap between actual energy performance and desired energy performance outcomes for a case study of 19 LEED-certified multi-unit residential buildings in the Greater Toronto Area. The study examines 1) how accurately design-stage energy modelling predicts actual energy use, 2) how much variation of energy performance can be seen between buildings of the same level of certification, and 3) the key contributing factors of this performance gap. Using EUI as the basis of comparison, trend analysis was carried out. It was determined that a performance gap between modelled and actual building energy use does exist. When compared to a larger sample of existing buildings, the case study buildings show no real improvement, on average. Regression models revealed no strong correlation between LEED Level or LEED EAc1 credits and reduced EUIs.

scholarly journals Testing a Gypsum Composite Based on Raw Gypsum with a Direct Admixture of Paraffin and Polymer to Improve Thermal Properties

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3241
Author(s):  
Krzysztof Powała ◽  
Andrzej Obraniak ◽  
Dariusz Heim
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Phase Change ◽  
Large Scale ◽  
Building Materials ◽  
Residential Buildings ◽  
Energy Performance ◽  
Polymer Content ◽  
Volumetric Heat Capacity

The implemented new legal regulations regarding thermal comfort, the energy performance of residential buildings, and proecological requirements require the design of new building materials, the use of which will improve the thermal efficiency of newly built and renovated buildings. Therefore, many companies producing building materials strive to improve the properties of their products by reducing the weight of the materials, increasing their mechanical properties, and improving their insulating properties. Currently, there are solutions in phase-change materials (PCM) production technology, such as microencapsulation, but its application on a large scale is extremely costly. This paper presents a solution to the abovementioned problem through the creation and testing of a composite, i.e., a new mixture of gypsum, paraffin, and polymer, which can be used in the production of plasterboard. The presented solution uses a material (PCM) which improves the thermal properties of the composite by taking advantage of the phase-change phenomenon. The study analyzes the influence of polymer content in the total mass of a composite in relation to its thermal conductivity, volumetric heat capacity, and diffusivity. Based on the results contained in this article, the best solution appears to be a mixture with 0.1% polymer content. It is definitely visible in the tests which use drying, hardening time, and paraffin absorption. It differs slightly from the best result in the thermal conductivity test, while it is comparable in terms of volumetric heat capacity and differs slightly from the best result in the thermal diffusivity test.

scholarly journals Life Cycle GHG Emissions of Residential Buildings in Humid Subtropical and Tropical Climates: Systematic Review and Analysis

Buildings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
Daniel Satola ◽  
Martin Röck ◽  
Aoife Houlihan-Wiberg ◽  
Arild Gustavsen
Keyword(s):  
Systematic Review ◽  
Life Cycle ◽  
Residential Buildings ◽  
Construction Materials ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Cycle Performance ◽  
Tropical Climates ◽  
Building Life Cycle ◽  
Total Life

Improving the environmental life cycle performance of buildings by focusing on the reduction of greenhouse gas (GHG) emissions along the building life cycle is considered a crucial step in achieving global climate targets. This paper provides a systematic review and analysis of 75 residential case studies in humid subtropical and tropical climates. The study investigates GHG emissions across the building life cycle, i.e., it analyses both embodied and operational GHG emissions. Furthermore, the influence of various parameters, such as building location, typology, construction materials and energy performance, as well as methodological aspects are investigated. Through comparative analysis, the study identifies promising design strategies for reducing life cycle-related GHG emissions of buildings operating in subtropical and tropical climate zones. The results show that life cycle GHG emissions in the analysed studies are mostly dominated by operational emissions and are the highest for energy-intensive multi-family buildings. Buildings following low or net-zero energy performance targets show potential reductions of 50–80% for total life cycle GHG emissions, compared to buildings with conventional energy performance. Implementation of on-site photovoltaic (PV) systems provides the highest reduction potential for both operational and total life cycle GHG emissions, with potential reductions of 92% to 100% and 48% to 66%, respectively. Strategies related to increased use of timber and other bio-based materials present the highest potential for reduction of embodied GHG emissions, with reductions of 9% to 73%.

scholarly journals Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

2021 ◽  
Vol 13 (4) ◽  
pp. 1595
Author(s):  
Valeria Todeschi ◽  
Roberto Boghetti ◽  
Jérôme H. Kämpf ◽  
Guglielmina Mutani
Keyword(s):  
Machine Learning ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Space Heating ◽  
Engineering Model ◽  
Building Energy Use ◽  
The Impact ◽  
The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

scholarly journals Managing energy performance in buildings from design to operation using modelling and calibration

2021 ◽  
pp. 014362442110083
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Dejan Mumovic ◽  
Mike Davies
Keyword(s):  
Best Practice ◽  
Good Practice ◽  
Energy Performance ◽  
Operating Conditions ◽  
Design Stage ◽  
Performance Gap ◽  
Actual Performance ◽  
Simulation Tools ◽  
Calibration Protocol ◽  
Covering Design

To manage the concerns regarding the energy performance gap in buildings, a structured and longitudinal performance assessment of buildings, covering design through to operation, is necessary. Modelling can form an integral part of this process by ensuring that a good practice design stage modelling is followed by an ongoing evaluation of operational stage performance using a robust calibration protocol. In this paper, we demonstrate, via a case study of an office building, how a good practice design stage model can be fine-tuned for operational stage using a new framework that helps validate the causes for deviations of actual performance from design intents. This paper maps the modelling based process of tracking building performance from design to operation, identifying the various types of performance gaps. Further, during the operational stage, the framework provides a systematic way to separate the effect of (i) operating conditions that are driven by the building’s actual function and occupancy as compared with the design assumptions, and (ii) the effect of potential technical issues that cause underperformance. As the identification of issues is based on energy modelling, the process requires use of advanced and well-documented simulation tools. The paper concludes with providing an outline of the software platform requirements needed to generate robust design models and their calibration for operational performance assessments. Practical application The paper’s findings are a useful guide for building industry professionals to manage the performance gap with appropriate accuracy through a robust methodology in an easy to use workflow. The methodological framework to analyse building energy performance in-use links best practice design stage modelling guidance with a robust operational stage investigation. It helps designers, contractors, building managers and other stakeholders with an understanding of procedures to follow to undertake an effective measurement and verification exercise.

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