Statistical analysis of the Greek residential building stock

The latest developments in the field of energy supply, along with the major issue of the environment protection, set new priorities and yardsticks concerning the energy policies implemented worldwide. The development and implementation of effective energy conservation policies has been a target of the European Union ever since the days when it was still called European Economic Community. In this framework, and despite the successes already monitored, the need for further energy conservation in the building sector is a both an aim and a tool. Emphasis is being placed on the residential building stock and the improvement of its energy performance. Greece has been one of the last countries to adopt the Directive on the Energy Performance of Buildings. A thorough research regarding the nature of the Greek residential building stock helps in highlighting the problems associated with this delay, but also the perspectives for catching up with the other EU member states and achieving the aims set for the coming years. This paper aims at providing detailed information on the residential urban building stock, as determined in a field study in typical big and smaller Greek cities.     

Policy options towards an energy efficient residential building stock in the EU-27

The EU-27 residential building stock offers high potential for energy efficiency gains. The policies already in place or proposed to improve the energy efficiency and thus the environmental performance focus on new buildings and major renovations of existing buildings. However, there might be additional measures that could lead to further energy efficiency improvements. In particular, the installation of roofs or windows that show a high thermal efficiency outside major renovations offer a large improvement potential. In this study, the potential environmental and economic impacts of two types of such policy options were analysed: first, measures that require high energy efficiency standards when roofs or windows have to be replaced; and, second, measures that accelerate the replacement of building elements. The results suggest that the two policies offer the potential for substantial additional energy savings. In addition, the installation of energy efficient building elements comes at negative net cost. When the replacement of building elements is accelerated, however, the additional costs do not outweigh the energy cost savings.     

The characteristics and the energy behaviour of the residential building stock of Cyprus in view of Directive 2002/91/EC

The significance of the residential building sector in terms of energy consumption is well acknowledged. In this view the knowledge of the way the residential building stock of Cyprus behaves in terms of energy consumption is quite valuable since it will assist policy makers to formulate targeted measures aiming the improvement of energy efficiency and setting current legal standards and benchmarks in the energy performance certificate, a requirement of the 2002/91/EC Directive. Unfortunately, the existing knowledge on this subject is quite poor. As a remedy a research project supported by a national research grant is in operation since December 2008. This paper presents the outline, goals and methodology of this research project and the findings regarding the energy behaviour and other characteristics of the residential building stock of Cyprus. From the analysis of the results for 500 residential buildings, it seems that the energy demand and primary energy required is lower than that of other European countries. Moreover, it seems that the age of residential buildings has low correlation with the energy demand while in contrast with other Northern and Central European countries, it is clear that the contribution of cooling energy requirements to the overall energy demand is quite significant.     

A methodology for assessing the energy performance of large scale building stocks and possible applications

From energy statistics (primary energy consumption) and a few Census data (residential buildings floor area) the average specific primary energy use (kWh/m²) of a territorial (Regional or National) building stock may be easily evaluated. However, can we achieve a deeper insight on this building stock using basically the same data bases? This is the question which this paper is aiming at, and the results is an analytical methodology to determine the Statistical Distribution Of residential Buildings according to primary Energy consumption for heating purposes (E-SDOB) at a Regional or National scale. This tool may allow the legislator to define a performance scale for building energy certification, to introduce mandatory measures and incentives for building energy retrofits, to evaluate the potential of new technologies, etc. The main source of data required for determining E-SDOB is still the National Census, but it has to be integrated by energy standards and laws, literature and a few data taken from the authors’ experience and in situ analysis. The results obtained have been compared with those derived from two Italian Regional (Piedmont and Lombardy) energy statistics, with excellent agreement.     

A review of bottom-up building stock models for energy consumption in the residential sector

Efficient and rational implementation of building stock CO₂ emission reduction strategies and policies requires the application of comprehensive building stock models that have the ability to: (a) estimate the baseline energy demand of the existing building stock, (b) explore the technical and economic effects of different CO₂ emission reduction strategies over time, including the impact of new technologies, and (c) to identify the effect of emission reduction strategies on indoor environmental quality.     

The effect of occupancy and building characteristics on energy use for space and water heating in Dutch residential stock

As a consequence of the improved quality of thermal properties of buildings due to energy regulations, overall energy use associated with building characteristics is decreasing, making the role of the occupant more important. Studies have shown that occupant behaviour might play a prominent role in the variation in energy consumption in different households but the extent of such influence is unknown. The impact of the building's thermal characteristics on space heating demand has been well studied. There is however, little work done that incorporates the impact of consumer behaviour. This study aims to gain greater insight into the effect of occupant behaviour on energy consumption for space heating by determining its effect on the variation of energy consumption in dwellings while controlling for building characteristics. The KWR database from the Ministry of Housing in the Netherlands was used. This study showed that occupant characteristics and behaviour significantly affect energy use (4.2%), but building characteristics still determine a large part of the energy use in a dwelling (42%). Further analysis showed that some occupant behaviour is determined by the type of dwelling or HVAC systems and, therefore, the effect of occupant characteristics might be larger than expected, since these determine the type of dwelling.     

福建省典型气候区居住建筑适时通风节能研究

本文基于福建近年新建住宅的调查调查结果,提取了1梯2户住宅的模式;根据这种模式和现有节能标准,构建了2单元6层住宅,并用软件模拟分析了其在福建典型气候区适时通风与非适时通风的能耗状况。模拟分析表明：（1）无论气候区如何,通风是否适时,住宅南北向布置时能耗最小,而东西向布置时能耗最大;（2）适时通风的节能效果与地区气候有...     

A cost effective approach to design of energy efficient residential buildings

The objective of this study is to identify cost-optimal efficiency packages at several levels of building energy savings. A two-story residential building located in Jordan is selected as a case study. DesignBuilder software is used to predict the annual energy usage of a two-story residence in Irbid, Jordan. Real-time experimental data from a single isolated controlled room was used to verify the proposed model. In addition to energy analysis, the economic, environmental, and social benefits of the proposed design have been investigated. The sequential search optimization approach is used to estimate the minimum cost of the building while considering various design scenarios. In addition, the impact of various energy conservation techniques on residential buildings is assessed, and the payback period for each program is calculated. Ultimately, the optimal combination of design to achieve energy efficiency measures has been identified in several climate regions. The simulations results predict that the annual electricity consumption can be reduced up to 50% if the proper combinations of energy conservation measures are selected at the lowest cost. The payback period is 9.3 years. Finally, energy efficiency measures can lead to a total of 9470 jobs/year job opportunities.The study provide practical framework to link between energy performance criteria and economic goals of building. Linking the energy performance requirements to economic targets provides guidelines for homeowners, contractors, and policymakers for making a suitable decision regarding the retrofitting of existing residential buildings. The study focuses on developing new methodologies that support minimizing costs during a building's lifecycle while maximizing environmental benefits which can not be identified by a series of parametric analyses using individual energy-efficient measures.     

Resilience to increasing temperatures: residential building stock adaptation through codes and standards

The resilience of the current Spanish residential building stock to increased temperatures is modelled. Homogenized daily temperature data recorded at 50 Spanish meteorological stations for the periods 1950–1979 and 1981–2010 were used to investigate anticipated climate warming on the Spanish residential building stock by means of the degree-day method. Impacts on residential buildings were investigated for three different future time periods (2011–2040, 2041–2070 and 2071–2100) for three representative Spanish provincial capitals. Future climate change scenarios comprising two statistical downscaling methods, three general circulation models and two carbon emission scenarios were used to project local climate. Results show that 72% of current residential building stock in Spain is thermally unprotected. In addition, the energy demand for heating the building sector in Spain is expected to decrease by between 30% (Barcelona, B2 scenario) and 36% (Valencia, A2 scenario) by 2100, while the respective energy demand for cooling could increase by between 107% (Valencia, B2 scenario) and 296% (Madrid, A2 scenario) by 2100. To increase resilience to higher winter and summer temperatures, strategies for modifying the built environment are needed, particularly for the role of building codes and standards.

La résilience du parc bâti résidentiel espagnol actuel face à l'augmentation des températures est modélisée. Les données homogénéisées des température journalières enregistrées dans 50 stations météorologiques espagnoles pour les périodes 1950–1979 et 1981–2010 ont été utilisées pour étudier le réchauffement climatique prévu sur le parc bâti résidentiel espagnol en utilisant la méthode des degrés-jours. Les répercussions sur les immeubles résidentiels ont été étudiées pour trois périodes futures différentes (2011–2040, 2041–2070 et 2071–2100) et pour trois capitales provinciales espagnoles représentatives. Il a été utilisé des scénarios de changement climatique futur comprenant deux méthodes de réduction d'échelle statistique, trois modèles de circulation générale et deux scénarios d'émission de carbone pour prévoir le climat local. Les résultats montrent que 72 % du parc bâti résidentiel actuel de l'Espagne est dépourvu de protection thermique. Il est en outre prévu que la demande énergétique liée au chauffage dans le secteur du logement en Espagne diminue de 30 % (Barcelone, scénario B2) à 36 % (Valence, scénario A2) d'ici à 2100, tandis que la demande énergétique respective liée à la climatisation pourrait augmenter de 107 % (Valence, scénario B2) à 296 % (Madrid, scénario A2) d'ici à 2100. Afin d'augmenter la résilience face à des températures hivernales et estivales plus élevées, il est nécessaire de disposer de stratégies de modification du cadre bâti, concernant en particulier le rôle des codes et des normes du bâtiment.

Mots clés: stratégies d'adaptation, performances des bâtiments, réglementation du bâtiment, parc bâti, changement climatique, degrés-jours, surchauffe, confort thermique, vulnérabilité, Espagne     

Energy,economic and environmental performance of heating systems in Greek buildings

The introduction of natural gas in the Greek energy market broadened the options in the field of space heating. Residents in five major Greek cities can choose from a variety of different fuels and systems for heating their houses or working spaces; 12 more cities will be connected to the gas network within the next 5 years. Considering that space heating is the major energy consuming activity in the Greek building sector and that the environmental constrains imposed by the Kyoto protocol will be met only with difficulty, if at all, a strategy concerning the developments in space heating seems to be necessary. This however presupposes an elaborate analysis of the overall performance of the alternative systems, taking into consideration the particular conditions of the Greek energy system and the ‘established’ way of designing residential and mixed-use buildings. The present paper aims to present the empirical comparative results related to the three most popular heating systems operated in Greek multi-apartment and mixed-use buildings, which use three different fuels, respectively: a central oil-fired boiler, a unitary gas-fired boiler and unitary heat pumps.     

建筑节能在居住建筑设计中的应用

从建筑节能与规划设计、围护结构设计、周围环境设计这三个方面综合考虑建筑节能的一些技术手段,从设计的角度提出建造节能建筑的新思路,以引导人们进一步重视建筑节能,提高资源利用率,改善生态环境。     

Building typologies as a tool for assessing the energy performance of residential buildings - A case study for the Hellenic building stock

Successful strategies towards minimizing the energy consumption and greenhouse gas emissions attributed to the building sector require knowledge on the energy-related characteristics of the existing building stock. Despite the numerous studies on energy conservation applications in buildings, current knowledge on the energy-related characteristics of the building stock still remains limited. Building typologies can be a useful instrument to facilitate the energy performance assessment of a building stock. This work is based on a harmonised structure for European building typologies (TABULA) developed for residential buildings, but the methodology may be extended to the tertiary sector as well. National typologies are sets of model buildings with characteristic energy-related properties representative of a country's building stock. The model buildings are used as a showcase for demonstrating the energy performance and the potential energy savings from typical and advanced energy conservation measures (ECMs) on the thermal envelope and the heat supply system. The proposed Hellenic residential building typology is presented for the first time along with an assessment of various ECMs that are used for an estimate of the energy performance of building stock in Greece in an effort to meet the 9% indicative national energy savings target by 2016.     

住宅建筑防火层数确定的若干问题

本文通过"住建规"、"建规"、"高规"对住宅建筑层数折算不同规定的分析,仔细探讨了底层与顶部跃层扣减以及"临界层"的问题。希望通过对问题的探讨,扩展大家的视野以及解决疑难问题的思路。     

Modelling building stock geometry for energy,emission and mass calculations

The effect of energy efficiency measures is generally evaluated for one or only a few houses. While the energy and environmental optimization of a particular building design is crucial, this cannot easily draw generic conclusions for future building designs. A method is presented for considering the effect of building geometry in simplified energy and life cycle assessment studies. Based on architectural and functional considerations, realistic ranges were determined for the parameters describing the geometry of ‘technically feasible’ buildings and their relationships. These parameters include floor area, the number of storeys, the perimeter-to-floor area ratio, the ratio of the building envelope adjoining neighbouring heated buildings, the window ratio and frame factor, the density of partition walls, and the roof slope. An algorithm is developed for the random generation of a large building sample based on the realistic ranges of these geometric parameters. By analysing the results, it is possible to calculate the expected value, standard deviation and confidence interval of the sample. The application of the method is shown in an example. The cumulative non-renewable energy demand is calculated for the whole life cycle and for different building types.

On évalue généralement l'effet des mesures de l'efficacité énergétique sur une ou seulement quelques habitations. Alors que l'optimisation énergétique et environnementale d'un modèle de bâtiment particulier est essentielle, elle ne permet pas de tirer facilement des conclusions génériques pour les futurs concepts de bâtiments. Cet article présente une méthode qui permet de prendre en considération l'effet de la géométrie d'un bâtiment dans des études d'évaluation simplifiées de l'énergie et du cycle de vie. En s'appuyant sur des considérations architecturales et fonctionnelles, on a défini des plages réalistes pour les paramètres décrivant la géométrie de bâtiments « réalisables sur le plan technique » et leurs relations. Ces paramètres incluent la surface au sol, le nombre de niveaux, le ratio entre le périmètre et la surface au sol, le ratio de l'enveloppe de bâtiments chauffés se trouvant à proximité, le ratio des fenêtres et le facteur de châssis, la densité des cloisons et la pente du toit. Un algorithme a été calculé pour la génération d'un grand échantillon aléatoire de bâtiments basé sur des plages réalistes de ces paramètres géométriques. En analysant les résultats, on peut calculer les valeurs escomptées, les écarts standard et l'intervalle de confiance de l'échantillon. L'application de cette méthode est décrite au moyen d'un exemple. La demande cumulée en énergie non renouvelable est calculée pour l'ensemble du cycle de vie et pour différents types de bâtiments.

Mots clés: géométrie des bâtiments, morphologie des bâtiments, parc bâti, efficacité énergétique, évaluation du cycle de vie, bâtiments résidentiels, Hongrie     

Assessment of climate change impact on residential building heating and cooling energy requirement in Australia

This study investigated the potential impact of climate change on the heating and cooling (H/C) energy requirements of residential houses in five regional climates varying from cold to hot humid in Australia. Nine General Circulation Models (GCMs) under three carbon emission scenarios were applied to project the local climate. It was found that significant climate change impact on H/C energy requirements may occur within the lifespan of existing housing stock. The total H/C energy requirement of newly constructed 5 star houses is projected to vary significantly in the range of −26% to 101% by 2050 and −48% to 350% by 2100 given the A1B, A1FI and 550 ppm stabilisation emission scenarios, dependent on the existing regional climate. In terms of percentage change, houses in an H/C balanced temperate climate such as Sydney is found to be the most sensitive to climate change, potentially posing more pressures on the capacity of local energy supply. It was also found that energy efficient or high star rating houses may experience less absolute changes in energy requirement. However, they appear to experience higher percentage changes in the total H/C energy requirement. Especially in the regions with an H/C balanced temperate climate such as Sydney, the increase in the total H/C energy requirement is projected up to 120% and 530% for a 7 star house when the global temperature increases 2 °C and 5 °C respectively. The high sensitivity to global warming may need to be considered in the planning of future energy requirement for energy efficient buildings.     

A statistical method to investigate national energy consumption in the residential building sector of China

The purpose of this research is to found a national statistical system of energy consumption in the residential building sector of China, so as to look into the actuality of residential energy consumption, and to provide data support for building energy efficiency work in China. The frame of a national statistical system of residential energy consumption is presented in this paper, according to current status of the climate, social and historic conditions, and energy consumption characteristics in the five architecture climate divisions in China. The statistical index system of residential energy consumption is constituted which refers to housing unit characteristics, household characteristics, possession and utilization of energy consuming equipment, and residential energy consumption quantities. This index system suits for all the different utilization structures of residential energy consumption in different architecture climate divisions. On this base, a complete set of statistical reports is worked out to measure the energy consumption of cities, provinces and the country stage by stage. Finally the statistical method above is applied to measure residential energy consumption by case studies, in order to validate the feasibility of this method. The research in this paper covers the first step of the elaboration of the statistical method to investigate energy consumption in China, and more work will be done in future to further impel national statistics of residential energy consumption.     

Application of energy rating methods to the existing building stock: Analysis of some residential buildings in Turin

The objective of this work is to contribute to the recent standardisation activity, finalized to apply the Energy Performance of Buildings Directive (EPBD). Through the energy assessment of some residential buildings in Turin (Italy), the work investigates the application of the calculation methods that have been specified in the recent European standard for the so-called “standard energy rating”. A comparison of the “calculated energy rating” with the “measured energy rating” is used to investigate the effect of user behaviour and weather conditions. Moreover, in order to draft the energy certificate and make an appropriate classification, the last part of the work investigates the way to find energy reference values of the building stock, through the study of the correlation between the input and the output data of an energy rating and the comparison of the analysed buildings.     

Modelling a whole building stock: domestic,non-domestic and mixed use

ABSTRACT

Work on energy use in buildings – in university research, professional practice and government – has tended to draw a broad distinction between ‘the domestic stock’ and ‘the non-domestic stock’. A further tendency has been to focus attention on types of non-domestic buildings devoted to single uses (e.g. offices, shops or hospitals). This paper reports an empirical research programme in which the complete building stock in large areas of England and Wales is comprehensively represented in great detail, using a new method and model called 3DStock. The model breaks down activities by floor level and within each floor of every building. The results show that the extent of mixing of uses is much greater than has previously been acknowledged, especially towards the centres and in the older parts of towns and cities. These mixed-activity buildings are sometimes relatively simple combinations of domestic and non-domestic, e.g. urban retail with flats above, while others are complex mixtures of different non-domestic activities. The model can be used to investigate how these complex relationships influence energy use. It is argued that, at the larger scale, explicit account needs to be taken of the mixing of uses in future stock models for research and policy-making.     

Understanding the New Zealand non-domestic building stock

Unlike the residential building stock, most countries have poor information on their non-domestic stock. This necessitates the use of other data sources. In the mid-1980s the (then) New Zealand Department of Valuation digitized its valuation records. This permitted the first analysis of an entire country's non-domestic buildings. A very long-tail probability density function was identified, with the largest 5% of buildings containing more than 40% of the floor space. This knowledge informed the development of research for understanding non-domestic buildings as well as underpinning the 1996 revision of the NZ Building Code Clause H1 Energy Efficiency. More recently an analysis of valuation data has provided the Building Energy End-use Study (BEES) with a national sampling frame to examine energy and water end-uses in non-domestic buildings. The development of processes for collecting and analyzing data is described. Considerable changes in understanding of valuation data have occurred for documenting the non-domestic building stock. New online and geographic information sources can validate and improve building data. The use of such a database supports improved understanding of the changing nature of the building stock and potential intervention points, as well as harnessing regulatory and market forces.     

浅析住宅建筑施工中防渗漏的控制措施

针对住宅工程施工中由于所采取的技术措施不当造成的渗漏质量通病,提出了在施工实践中应采取的屋面防渗漏、外墙面防渗漏、外墙窗口防渗漏、楼层及卫生间的防渗漏措施,以提高住宅建筑施工质量.