Energy Performance Certificates Research Articles

Land management criteria for green building certification systems in Turkey.

The issue of energy holds significant implications for nations heavily reliant on it, such as Turkey. In recent times, legislative measures, including the Energy Efficiency Law and the Energy Performance Regulation of Buildings, have been enacted in Turkey. Despite the implementation of the Energy Performance Certificate for buildings, the absence of a national green building certification system remains conspicuous. To address this gap, an examination of globally recognized certification systems and relevant components concerning land management, pertinent to Turkey's context, was undertaken. This involved a comprehensive literature review to establish the foundation for survey inquiries. Subsequently, interviews were conducted with subject matter experts in Turkey to glean valuable insights and perspectives. Utilizing the Analytic Hierarchy Process (AHP) methodology, the responses from these experts were collated and analyzed to delineate the criteria and sub-criteria germane to land management. This study delves into the discourse surrounding the establishment of a green building certification system within Turkey, specifically within the domain of land management, a sector of paramount importance, particularly within the purview of survey engineering. Through a structured survey, the criteria pertinent to land management were identified and subjected to rigorous analysis. Furthermore, the sub-criteria within the land management category were delineated, and their respective weights were computed, thereby providing a comprehensive framework for the envisioned green building certification system in Turkey.

Enhancing buildings' energy efficiency prediction through advanced data fusion and fuzzy classification

This study proposes a method to predict buildings' energy efficiency based on available descriptive information and without a physical visit, by merging diverse datasets and employing advanced classification techniques. By integrating geographical, structural, legal, and socio-economic data with Energy Performance Certificate (EPC) observations, our approach yields a rich learning set. Through variable selection methods like forward selection with KNN and simultaneous perturbation stochastic approximation for fuzzy KNN, we refine model variables. Comparing fuzzy and hard classification using KNN, Kriging or Random Forest approaches, we find fuzzy classification more adept at capturing nuanced energy inefficiency indicators. Our study highlights the importance of mass energy efficiency prediction for sustainable renovation efforts.

Energy Performance of Buildings for Incentivisation in Energy-Efficient Structures: An Analysis of Secondary Data in Malta

High-performance green buildings mitigate the adverse environmental effects of energy consumption and carbon emissions while simultaneously demonstrating that sustainability does not mean compromising utility, productivity, or comfort. We need to address the identified gap in the evolution of energy-efficient structures facilitated in building applications to enhance energy usage without mitigating comfort. The aim of this study was to provide a review of the current methods used to assess energy efficiency in buildings in Malta through secondary data and to supplement this with qualitative data from interviews. The study investigated the importance of certification, compulsory legislation, and regulations implemented by local authorities and the European Union to incentivise energy performance measures. The findings, supplemented with qualitative data from representatives of public entities, show that most participants agreed that the current method of assessing needs requires a complete overhaul in order to promote a proactive approach to sustainable development. Recent public awareness has highlighted the limited understanding of sustainable practices implemented in buildings to capture and conserve energy. However, it is widely recognised that the building industry has significant potential for energy savings, which applies to both new constructions and existing structures, but the current level falls short of what is necessary in Malta. The study findings emphasise the primary energy users and pinpoint the obstacles in the implementation process. In conclusion, the use of software EPRDM, which may be applied to raise the importance of energy performance in building standards, lacks a value-driven focus, resulting in its full utilisation and potential being unexplored. Future applications of this study include the categorisation of old buildings for a possible bid in energy retrofit; campaigns to promote responsiveness; and the utilisation of advanced technological tools, such as DESIGNBUILDER and related software, to enable the simulation of an optimal building envelope. While increased energy efficiency may result in elevated rental and sale prices for buildings, this knowledge, when disseminated to prospective purchasers via the energy performance certificate (EPC) system, can catalyse investments in structures that are more energy efficient for the end user.

Developing a Data-Driven AI Model to Enhance Energy Efficiency in UK Residential Buildings

Residential buildings contribute 30% of the UK’s total final energy consumption. However, with less than one percent of its housing stock being replaced annually, retrofitting existing homes has significant importance in meeting energy-efficiency targets. Consequently, many physics-based and data-driven models and tools have been developed to analyse the effects of retrofit strategies from various points of view. This paper aims to develop a data-driven AI model that predicts buildings’ energy performance based on their features under various retrofit scenarios. In this context, four different machine learning models were developed based on the EPC (Energy Performance Certificate) dataset for residential buildings and standard assessment procedure (SAP) guidelines in the UK. Additionally, an interface was designed that enables users to analyse the effect of different retrofit strategies on a building’s energy performance using the developed AI models. The results of this study revealed the artificial neural network as the most accurate predictive model, with a coefficient of determination (R2) of 0.82 and a mean percentage error of 11.9 percent. However, some conceptual irregularities were observed across all the models when dealing with different retrofit scenarios. All summary, such tools can be further improved to offer a potential alternative or support to physics-based models, enhancing the efficiency of retrofitting processes in buildings.

A Case Study of Nine Post-Hydrocarbon Ready Homes

A typical 2bed dwelling at Howgate Close, after 16months of occupation, has a daily average energy bill of 10pence/day/dwelling [1] It is proffered that Howgate Close may be the most energy efficient group of dwellings of its type, in the UK [2]. Howgate Close is a residential neighbourhood of nine single storey dwellings, operating free of fossil fuels, they are post-hydrocarbon ready. The development is located in Nottinghamshire, UK, and was completed in June 2022. All nine homes are a net annual generator of surplus renewable energy, with little to no heating demand. Six of the nine homes remain naturally heated, with no resort to the electric underfloor heating system. Exceptionally high levels of energy efficiency have been achieved with third-party verification, the As-Built SAP Rating of 143A [3] Such a rating places these homes in the top 0.01% of the 12million registered UK Energy Performance Certificate‘s (EPC) [4]. This paper provides a building Case Study that evidences performance standards making comparisons with the UK Building Regulation Compliance Standards [5] Howgate Close’s exceptional energy efficiency can be described as an aggregation of marginal gains [6] This paper is a prelude to more forensic analysis of Howgate’s in-use building performance, with the installation more advanced monitoring equipment in May 2024 for a period of two years. EWI Pro, Dr Harrall and Nottingham Trent University (NTU) are to undertake further data dissemination, providing a more forensic Howgate Case Study for ISEC 2025.

A Comparative Study on Discrepancies in Residential Building Energy Performance Certification in a Mediterranean Context

Energy Performance Certification (EPC) systems are pivotal in addressing the global energy challenge, particularly in the building sector. This study evaluates the efficacy of the EPC offered by the Simplified Building Energy Model interface designed to indicate compliance with the Cypriot building regulations, widely known as iSBEM-Cy Version 3.4a, by examining a typical residential unit in Cyprus. Data on construction features and electromechanical systems were collected, and actual monthly electricity and oil bills were analyzed to determine the total primary energy consumption. Various factors were considered, including energy efficiency and operational parameters for heating, cooling, lighting, auxiliary systems, and domestic hot water. The building energy performance was simulated using iSBEM-Cy, allowing for comparison with real-world energy consumption. Notable discrepancies were observed, particularly in cooling, with deviations reaching 377.4%. Conversely, domestic hot water consumption exhibited minimal variance at 7%, while heating and lighting showed moderate discrepancies (24.3% and −113.9%, respectively). This study underscores the need for rigorous evaluations to shape effective EPC and provides insights into building energy performance in Mediterranean Cyprus. This research contributes to the broader discourse on sustainable construction practices by aligning simulation results with real-world energy consumption.

Analysis of the Energy Consumption for Heating in Schools

Abstract The aim of the study is to analyse energy consumption for heating in set of the school buildings. Data analysis includes three data sets – predictions from energy performance certificates (EPC), measured data from heat meters and measured climate corrected data. Data sets were statistically checked and processed and represented graphically. The actual energy consumption differs from the one stated in the EPCs in all cases, which means that schools consume on average 15 % more energy than it is stated in the EPC. Overall, the data reveal that the actual energy consumption differs from the theoretical consumption, with all schools having higher actual consumption than the theoretical values. The differences in the data sets are discussed, and possible improvements are suggested taking into account strong relation between energy consumption and indoor air quality.

Sustainability and Resilience Assessment Methods: A Literature Review to Support the Decarbonization Target for the Construction Sector

It is a well-known issue that the 2050 target of carbon emissions neutrality will be reached only with the co-operation of all the interested sectors, and the construction sector could be one of the main contributors to this change. With the built environment globally responsible for about 40% of annual global energy-related CO2 emissions, the construction sector offers an important opportunity to drive transformative change and presents the most challenging mitigation potential among all industrial sectors, which also brings opportunities for adopting sustainability practices and increasing resilience. This paper presents a systematic literature review of those two pivotal concepts to reach the decarbonization goal: sustainability and resilience. Starting from an extensive literature review (2536 scientific documents) based on the PRISMA statement, the definitions and assessment methodologies of those concepts for the construction sector have been studied. The methodological approach followed for their analysis has been conducted on a first selection of 42 documents, further reduced to 12 by using clear inclusion criteria to identify the integrated assessment procedures. The main goal of this study is to clarify the correlation between sustainability and resilience concepts for constructions and their integrated assessment, in line with the latest regulations and market needs. The results show that, currently, sustainability and resilience are mainly evaluated in a distinct way to obtain building energy performance certificates, as well as to quantify the building market value and its complementary contribution to the ‘energy efficiency first’ principle and energy-saving targets towards the emergent issue of climate change. Few works focus on the integrated assessment of both concepts considering the construction industries’ point of view about materials and/or systems for buildings. The novelty of this study is the critical review of the current sustainability and resilience integrated assessment methods used for the construction value chain, declined for four main target groups. Researchers, policymakers, industries, and professionals could gain dedicated insights and practical suggestions to put in practice the elements of circular economy, ecological innovation, and cleaner production, which are essential in order to drive the decarbonization of the built environment.

The effects of Energy Performance Certificates in energy poverty: A brief overview

<p class="MsoNormal" style="margin-top: 8pt; line-height: 14pt; text-align: justify;"><span lang="EN-US" style="font-family: verdana, geneva, sans-serif; color: black;">Energy Performance Certificates are a key tool for achieving energy efficiency in the building sector. The existence of this type of legislation provides incentives for the energy renovation of buildings, increases energy-efficiency investments, and improves social welfare. At the same time, informational asymmetries are mitigated and energy consumption is reduced. However, the decarbonization of the building sector might influence regional energy poverty, especially because the rural energy poor are more vulnerable to energy price increases than their urban counterparts. Empirical research on rural-urban differences and the effects of Energy Performance Certificates is urgently needed, given the rising fuel prices and vulnerabilities of the energy market.</span></p>

Improving the Energy Performance of Public Buildings in the Mediterranean Climate via a Decision Support Tool

Addressing Europe’s decarbonisation challenge involves widespread deployment of nearly zero-energy buildings, deep energy renovations and renewable energy integration in the building sector. Enhancing energy efficiency in public buildings necessitates tailored solutions and strategic planning involving Local Public Administration. This work focuses on advancing insights into the application of the PrioritEE Decision Support Tool in Portuguese public buildings, highlighting the energy and financial savings and carbon dioxide emission reduction potential. Using detailed building characterisation data from energy performance certificates, we applied the tool across 22 public buildings of diverse typologies in three distinct regions of Portugal, representing various public entities. Results demonstrate the tool’s adaptability, enabling a comprehensive assessment of energy performance and facilitating the exploration of customised energy efficiency and renewable energy solutions. The research emphasises the critical role of user-friendly tools in aiding policymakers and local administration technicians in meeting national renovation targets and contributing to the broader energy transition objectives.

New generation Energy Performance Certificate: Development and application in an Italian case study as an EU proof of concept

The Energy Performance of Buildings Directive recast, voted in March 2024, aims to boost the amelioration of the Energy Performance Certificate (EPC) with the introduction of new indicators in a dedicated template (Annex V), as a key tool towards the decarbonization of the building sector, in line with the Green Deal’s climate neutrality goals. In this context, the H2020 Energy Performance Certificate Recast project develops a new generation of EPC focused on existing residential buildings. The paper presents the state of progress of the Energy Performance Certificate Recast methodology, comparing it with the standard national procedure in different EU partner countries. The novelty of the work is the testing methodology of a new generation of this tool, which aims to overcome the barriers identified in the current EPC procedure across Europe and to validate the reliability and user-friendliness of this new approach. The final goal of the work is to prove the applicability and potentialities of this innovative approach, providing a clear and punctual presentation of each step of the assessment and the testing methodology of the new generation of Energy Performance Certificate, coupled with its application in an Italian case study as a Proof of Concept.

Energy Performance Certificates and the Capitalization of Utility Costs in Rents: The Potential Role of Asymmetric Information and Uncertainty

This paper is the first to investigate the relationship between the energy efficiency of dwellings, measured by the energy performance certificate (EPC), and utility cost inclusion in rental prices. First, we investigate potential drivers behind the decision to include utility costs in rents. We find that labeled dwellings are more likely to include utility costs and that this likelihood is higher among energy-efficient dwellings than among inefficient dwellings. Next, we surprisingly find that utility costs seem to be under-capitalized in energy-inefficient dwellings. These results are confirmed with the counterfactual decomposition approach. Overall, the findings indicate that the EPC labeling policy may be important for both landlord and tenant decision-making and may enhance market efficiency.

Improving energy efficiency in Portuguese buildings: Retrofitting façades with high reflectance finishing coat

The European Union must enhance energy efficiency in its building stock, given that buildings account for up to 40% of the EU's energy consumption. Currently, more than 85% of buildings have been in use for over two decades, with at least 75% lacking energy efficiency. Only 10% of the building stock achieves ‘A’ or ‘B’ ratings in energy performance certificates. To meet energy efficiency standards, retrofitting exterior walls with passive techniques, such as enhancing optical properties, proves highly effective. Employing high reflectance surfaces reduces solar heat absorption, thereby lowering cooling energy use. This study examines the impact of reducing surface temperature through an external thermal insulation system with a high reflectance finishing coat during building envelope renovation in various climatic zones in Portugal. Preliminary findings indicate that high reflectance has a more substantial effect on annual heat gain for moderately insulated walls than well-insulated ones. The effect varies with maximum air temperature, especially in hot summers. A change in reflectance can improve heat gain reduction, especially considering the cost of retrofitting with insulation materials. An optimal balance between reflectance and thermal resistance is key to achieving lower surface temperatures and reducing cooling energy demands for Portuguese climates.

Impact of the 2022 Energy Crisis on the Importance of Energy Performance Certificates for the Real Estate Market

This study relies on a unique database covering different segments of the residential real estate market to investigate whether the value of energy performance certificates was affected by the energy crisis in 2022. Based on the relevant literature, the study uses the linear regression estimation method, in which the effect of interaction is examined using the difference-in-difference method. The study shows that energy performance certificates have a significant impact on the estimated market value of properties, both by individual category and in groups. While in 2022 Q2, before the residential energy price increase, an energy-inefficient property cost 12 per cent less on average compared to a property with an average energy rating, controlling for other factors, that difference increased to 20 per cent after the outbreak of the energy crisis. It may therefore be worthwhile for Hungary to consider taking measures to improve the energy efficiency of buildings as soon as possible.

The impact of the new EPBD “Green Houses” in the Italian building context: Technical-economic analysis on improving the energy class of existing buildings

The new European directive “Green Houses” aims at the decarbonization of the existing building stock. In this work, three building types widespread in Italy are analysed, virtually positioned in Palermo, Naples, and Milan. Considering that almost 60% of Italian residential buildings fall within the G and F energy classes, three energy retrofit measures are proposed (thermal insulation of vertical walls and roofs; replacement of the methane gas boiler for building heating and domestic hot water with a high temperature air-to-water heat pump; installation of a photovoltaic system), in order to reach at least D energy class based on Italian energy performance certification. A simulation-based approach is used. A declining tendency is noted in the normalized prices of the interventions when moving from detached house to terraced house and from terraced house to apartment in a tower building. Shifting from an independent to a centralized air conditioning system results in the same savings. Considering equal building features, hotter and milder climate zones reach higher energy classes; this also results in more difficult energy efficiency improvement in colder climates. Potential inequalities result from the implementation of the new European directive. Economic incentives to support the energy efficiency transition should be tailored to more specific conditions.

Assessing energy efficiency at urban scale through the use of energy performance certificates: An application in the Emilia-Romagna region, Italy

Energy retrofitting of residential buildings is considered a challenge to be tackled not only at building level, but also at urban scale, to give a stronger impulse for a concrete transition towards climate neutrality. This paper presents an easy-to-use analysis method based on the elaboration and scaling-up of data collected through the energy performance certificates (EPCs) to identify different urban energy zones distinguished by their energy performance index. This method is therefore conceived for better informing urban planning decisions, thus boosting more effective energy-sensitive urban planning strategies and eventually to foresee dedicated financial instruments to act in the more energy demanding areas of the city, establishing priorities for integrated strategies. This analytical method has been applied and tested in one municipality in the Emilia-Romagna region, Italy, where the recent urban planning law is pushing municipalities towards the development of urban planning strategies oriented to drastically improve the energy efficiency of the existing building stock. Results show that only a small number of areas manage to reach a good performance with fairly low levels of energy performance index, with the most critical situation found in the most central areas of the capital and in the hamlets.

A review of the 1-2 apartment residential building stock in Lithuania based on an analysis of Energy Performance Certificates

One of priorities of the EU’s climate change policy is the energy performance of buildings. This is reflected primarily through the series of Directives the EU has enacted along the years, but is most precisely conveyed in the Energy Performance of Buildings Directive (EPBD). As part of the European Union, Lithuania has enacted its own long-term strategy aimed at transforming the current building stock in one which is more energy efficient. Building energy certification, legalized in accordance with the requirements of the directive is the primary tool used to evaluate the energy-efficiency of a building, which includes determination of the energy consumption of a building and subsequently assigning it with an energy performance class. Energy performance certificates (EPC) are obligatory for new and existing buildings in all European Union (EU) member states and provide not only a description of the energy performance characteristics of individual buildings, but are also useful source of legal information for determination of the achievements of building energy efficiency improvement strategy. Despite the current wide spread presence of EPC analyses in other European countries, similar information on the national EPC register of Lithuania is still hardly present in research studies. To this effect this paper presents a detailed overview of the stock of Lithuanian residential 1-2 apartments buildings using data from the national EPC register. The results obtained present the impact of the implementation of EPBD on Lithuanian residential 1-2 apartments buildings, including changes in thermal insulation of building elements, heating system typology, energy consumption and CO2 emissions.

Over- and underconsumption of residential heating: Analyzing occupant impacts on performance gaps between calculated and actual heating demand

Previous research estimates that building physics and occupant practices equally contribute to the explanation of variations in residential heating consumption. However, the so-called performance gap, where calculated heating demand diverge from actual heating consumption, indicates that the relation between occupant practices and building physics vary across energy efficiency of the building. In this paper, using data from 2019 to 2021, we investigate such interactions 1) by comparing the calculated heating demand with actual energy consumption for residential space heating and domestic hot water (DHW) across energy performance certificates (A to G), and 2) by investigating variations in over- and underconsumption (deviance from calculated to actual) across socio-economic characteristics of households. In line with previous studies, we find that households living in energy inefficient houses tend to have lower heating demand than expected. Moreover, we find that lower-income households and households living in rural area has less overconsumption, indicating that they have more frugal heating practices.

Evaluating the indoor radon concentrations in the Swedish building stock using statistical and machine learning

Exposure to excessive indoor radon causes around 500 lung cancer deaths in Sweden annually. However, until 2020, indoor radon measurements were only conducted in around 16% of Swedish single-family houses and 17% of multifamily houses. It is estimated that approximately 16% of single-family houses exceed the indoor radon reference level of 200 Bq/m3, and the corresponding situation in multifamily houses is unknown. Measuring indoor radon on an urban scale is complicated and costly. Statistical and machine learning, exploiting historical data for pattern identification, provides alternative approaches for assessing indoor radon risk in existing dwellings. By training MARS (Multivariate Adaptive Regression Splines) and Random Forest (RF) regression models with the data labels from the radon measurement records in the Swedish Energy Performance Certification registers, property registers, soil maps, and the radiometric grids, the correlations between response and predictive variables can be untangled. The interplay of the key features, including uranium and thorium concentrations, ventilation systems, construction year, basements, and the number of floors, and their impact magnitudes on indoor radon concentrations, are investigated in the study. The regression models tailored for different building classes were developed and evaluated. Despite the data complexity, the RF models can explain 28% of the variance in multifamily houses, 24% in all buildings, and 21% in single-family houses. To improve model fitting, more intricate supervised learning algorithms should be explored in the future. The study outcomes can contribute to prioritizing remediation measures for building stocks suspected of high indoor radon risk.

Airtightness of Estonian dwellings – median and base-values for heat loss estimation.

The field measurements of airtightness in Estonian detached houses and apartment buildings, conducted between 2003 – 2022, were combined into a large dataset for statistical analysis. The buildings (539 in total) constructed between 1810 and 2022 were classified based on dwelling type, building structure, number of storeys, year of construction, energy classification and compactness factors. The data was statistically analysed to determine the mean and median air leakage rates at 50 Pa and tested (Kruskal-Wallis test with post-hoc Conover test) for significant differences within the grouping factors. Buildings constructed after the enforcement of the compulsory Energy Performance certification have on average across all building structure types significantly lower mean air leakage rate (1.6 m3/(h·m2)) than older buildings (6.9 m3/(h·m2)), although log-wood and brick construction types feature slightly higher average air leakage rate. Previous experience with air leakage measurements help to achieve better airtightness on building site. A systematic and recurring measurement practice within a single construction company leads to significantly lower air leakage also for new concrete buildings. Detailed assessment of older buildings showed that all timber-based construction types had significantly higher air leakage rate along with higher variability compared to precast large concrete panel stone and small block wall and brick buildings. All apartment buildings built before 2010 had significantly lower air leakage rate compared to detached houses while there was no difference in new buildings. Along with the mean and median value a base value of air leakage rate q E50,base was calculated for all construction types and age groups including 50% of measured buildings around the mean within each group with 84 % confidence interval. The calculated mean, median and base values of air leakage rate provide a way for more accurate heat loss estimation at the district-level or building-level modelling of energy saving potential of different retrofitting strategies based on building age, construction type and other building information data.