Bauliche Konzeptentwicklung für eine 3‐Liter‐Reihenhauszeile im Rahmen von Modernisierungsmaßnahmen in Mannheim‐Gartenstadt

Structural concept and detailing of a 3‐litre‐terraced houses on the occasion of modernization measures. Between 2001 and 2008, extensive refurbishment measures including partial renovation, complete modernisation, demolition works and subsequent new building development are scheduled for the residential area of Mannheim‐Gartenstadt. A total of 10 two‐storey residential houses built in the 1930s and the 1950s (comprising about 230 flats) are going to be refurbished. The flats are in a poor condition, not meeting nowadays standards regarding construction and technical installations. By conducting these structural measures, the GBG Mannheim housing society also follows the aim of improving the residential quarter’s attractiveness. Three buildings, including 68 flats, were to be modernised by the end of 2003. So far, refurbishment measures merely complied with the statutory requirements stipulated in the German regulations on energy conservation (EnEV), but future retrofitting measures for a terrace with 6 dwelling houses are to achieve a level of energy which will exceed these requirements by far. The energy performance of these buildings is to be substantially improved, with the aim of turning them into ’3‐litre houses’. Though this concept has been successfully implemented in new residential buildings, it is still a challenge for construction in existing buildings. Low‐energy buildings with an annual primary energy demand for heating of less than 34 kWh/m²a (inclusive of auxiliary energy) are referred to as ’3‐litre houses’. This corresponds to the primary energy content of 3 litres of heating oil.     

Bautechnisch‐bauphysikalische Beurteilung der Wirksamkeit energetischer Sanierungen am Beispiel städtischer Wohnhausanlagen in Wien

Study on the efficiency of thermal refurbishment of residential buildings in Vienna. In the framework of the Kyoto Protocol Austria has committed to reduce its greenhouse gas emissions until 2008/2012 by 13% on the base of 1990. Therefore the Federal Government as well as the provincial governments have implemented programs for the protection of climate including several measures to reduce the emission of hazardous greenhouse gases mainly CO₂. Regarding the enormous potential reduction activities were mainly focused on residential buildings. The refurbishment of the building envelope reduces the heating costs as well as the carbon dioxide emissions and improves the indoor climate. Several investigations were taken to check the utility of thermal refurbishment under structural and physical conditions. Plenty of data available in the line of several expertises of existing residential buildings were analysed and completed by additional investigations. The economic efficiency of thermal insulations is pointed out as well as the period of repayment or the influence of the thickness of insulation on the heating energy demand or possible CO₂‐reductions.     

Evaluation of traditional architecture in terms of building physics: Old Diyarbakír houses

Diyarbak?r is located in the southestern part of Turkey. Traditional Diyarbak?r houses are successful examples of buildings adapted to a hot dry climate. This is achieved by conforming to an old style of living and by the requirements and the use of local materials. In this study, the general architectural properties of the traditional houses of Diyarbak?r, their layouts, plan types, building envelope and facade elements are evaluated in terms of building physics criteria. Today, in spite of new technological advances, techniques and materials, identical buildings are still being built, and climatic design is not considered important in Diyarbak?r. As a result these buildings do not provide shade and cool spaces, and thus cause thermal discomfort, or increase in the use of energy. The aim of this study is to emphasize the importance of the features of traditional buildings in terms of designing energy efficient, to provide appropriate buildings for the environment.     

Energy conservation in 29 historic school buildings in Palermo

In the rehabilitation programme of 29 old school buildings in Palermo energy conservation measures were included.

By means of simulation models, several options were examined, ranging from solar active systems to properly designed heating systems.

The study showed, because of the characteristics of the buildings, their occupation pattern and the mild climate, that the most cost-effective option was a properly controlled heating system.

Italian energy conservation building regulations were shown to be scarcely suitable to the cases examined, and a certain resistance to technological innovation was found in some designers, especially the older ones.     

Zero energy balance and zero on-site CO2 emission housing development in the Mediterranean climate

Zero energy balance (ZEB) is an essential and paramount topic in building design. The paper addresses this important research area with special regard to the Mediterranean climate.To deal with ZEB in architecture, a final design proposal for a new housing development in the peri-urban context of Tricase - a town located in the south of Italy - is presented and used for energy investigation. With reference to this pilot case study, the paper highlights that high performing and zero energy balance buildings cannot be reached by technology alone, but by the search for an integrated design combining passive tools (high thermal mass brick wall structures - as an evolution of the traditional stone construction of the region, high reflective materials, solar shading devices, ventilation strategies, etc.) with solar and wind energy micro-generation.Results show that zero energy balance and zero local CO₂ emission houses in the Mediterranean climate present high levels of feasibility, which can be simply achieved by energy-efficient solutions using local materials and traditional construction processes, thus resulting into high quality performing buildings within recognisable urban environments.     

The potential and need for energy saving in standard family detached and semi-detached wooden houses in arctic Greenland

The paper gives an account of the potential and need for energy saving in standard family detached and semi-detached wooden houses in Greenland. It is based on studies of house construction compared with Building Regulation requirements and the spread of buildings over time. In the climatic conditions of Greenland, there is considerable potential for energy saving in houses due to their construction, shape and condition. To estimate the total potential for energy saving and thus reducing CO₂ emissions, we carried out a detailed investigation of three typical standard semi-detached family houses (type 18D). Temperature, relative humidity and air tightness were measured, and thermal bridges were determined from drawings, visual inspection, and by using a thermal camera. The findings show a current energy consumption of up to 383 kWh/(m² a) for heating, poor air tightness, a large number of thermal bridges, and high indoor temperatures. We demonstrate a potential for a reduction in CO₂ emission by a factor of 10. Finally, the paper describes a practical way of reducing thermal bridges significantly, increasing air tightness, upgrading insulation and adding mechanical ventilation to approximately half of the housing stock without changing the architectural expression or having to relocate the occupants during the renovation.     

代际互助模式下东北寒地城市住宅改造研究

在严酷的气候背景及社会发展背景下,东北寒地城市具有大量既有住宅亟待改造,全面的改造不仅仅是建筑节能性能的提高,也包含居住模式变化对建筑空间环境产生的改造要求。近年来,我国应对老龄化趋势在人口政策方面做出了大幅度调整,通过解析东北寒地城市既有住宅的本质特征及适老化需求特点,分析其改造关键问题,以积极老龄化理念为指引,发掘"代际互助模式"在该地区住宅改造中应用的可行性,建构基于此模式的东北寒地城市既有住宅改造研究平台。     

The impact of thermal bridges on the energy demand of buildings with double brick wall constructions

The implementation of the European Directive on the Energy Performance of Buildings (EPBD) is a milestone towards the improvement of energy efficiency in the building sector. However, even in cases where impressive measures can be implemented in the densely built urban environment, the less glamorous measure of building's envelope thermal insulation remains a prerequisite towards the improvement of the building's energy efficiency. Despite the insulation requirements specified by national regulations, thermal bridges in the building's envelope remain a weak spot in the constructions. Moreover, in many countries construction practices tend to implement only partially the insulation measures foreseen by regulations. As a result, thermal losses are in practice greater than those predicted during the design stage. This paper presents a study on representative wall thermal insulation configurations used in Greek buildings, in order to investigate the impact of the thermal bridges on the energy consumption. The double wall construction, used widely in Greece and not only there, is rather susceptible to the occurrence of thermal bridges, in contrast to a typical thermal insulating façade, like the one applied in Central Europe. The analysis of the thermal bridges’ impact will in that sense also highlight the potential for energy renovation measures in older buildings.     

Climate change adaptation pathways for Australian residential buildings

Climate change can significantly impact on the total energy consumption and greenhouse gas (GHG) emissions of residential buildings. Therefore, climate adaptation should be properly considered in both building design and operation stages to reduce the impact. This paper identified the potential adaptation pathways for existing and new residential buildings, by enhancing their adaptive capacity to accommodate the impact and maintain total energy consumption and GHG emissions no more than the current level in the period of their service life. The feasibility of adaptations was demonstrated by building energy simulations using both representative existing and new housing in eight climate zones varying from cold, temperate to hot humid in Australia. It was found that, in heating dominated climates, a proper level of adaptive capacity of residential buildings could be achieved simply by improving the energy efficiency of building envelop. However, in cooling dominated regions, it could only be achieved by introducing additional measures, such as the use of high energy efficient (EE) appliances and the adoption of renewable energy. The initial costs to implement the adaptations were assessed, suggesting that it is more cost-effective to accommodate future climate change impacts for existing and new houses by improving building envelop energy efficiency in cooling dominated regions, but installing on-site solar PVs instead in heating and cooling balanced regions.     

Dauerthema Wärmebrücken – Praxishinweise zur Anwendung von DIN 4108 Beiblatt 2 und zum energetischen Einfluß von Wärmebrücken

Endless story thermal bridges – practical remarks regarding the use of DIN 4108 Supplement 2 and the influene of thermal bridges on energy use The concept of dealing with the influence of thermal bridges on the energy use of buildings is given in the current German ordinance on energy savings in buildings (EnEV 2001). The well established approach is adopted and enhanced for thermal bridges both in new and existing buildings in the future edition of that ordinance, EnEV 2006 and in DIN V 18599‐2 which is to be used for non‐residential buildings in the future. When using the reduced (estimated value) for thermal bridges in the legal energy saving calculation, the planner of the building has to consider the examples for planning and performance in DIN 4108 Supplement 2. He also has to confirm that his individual solution for a thermal bridge is equivalent in energy terms to the given examples.In time for the new EnEV 2006, the DIN 4108 Supplement 2 is currently under revision. The once introduced concept is kept in principle and at a few points made more real‐life compatible or amended. The paper describes how thermal bridges are taken into account in the named legislation and gives remarks as to scope and meaning of DIN 4108 Supplement 2. Using practical examples the pssoble influence of thermal bridges on overal thermal transmission is demonstrated.     

Study of thermal environment inside rural houses of Navapalos (Spain): The advantages of reuse buildings of high thermal inertia

The main purpose of a residential building is to provide a comfortable environment for human activities. Nowadays this objective is the responsible for the consumption of more than 40% of total energy demand in European Union. The construction sector in Spain has been in rapid growth in the last decades, yet there exists many abandoned buildings in rural areas. In this article we try to analyze the environmental advantages of reuse abandoned rural buildings. Due to their thick exterior walls of high thermal inertia, the indoor environment inside them can be comfortable with less energy consumption than new buildings. Here we show the monitoring results of three different houses, two traditional and one modern building, constructed of different building materials. The aim of this work is to analyze and compare the thermal behaviour of existing constructive solutions in a Spanish district, not to improve them. The field test results show better indoor conditions inside the traditional houses. In summer, thermal comfort is achieved with no energy supply inside traditional houses but not inside the modern one. In winter, the indoor environment is more stable inside the traditional houses, however none of them were able to provide thermal comfort naturally. In the case studied, the only inhabitant of a small village lives in a prefabricated wooden house, and it is demonstrated that the indoor conditions of traditional houses in the same location are of higher quality.     

The use of tuff stone cladding in buildings for energy conservation

Heating the houses in cold climates requires large quantities of heat energy to be spent. The building sector consumes more energy in the form of heat than other sectors. Therefore, considerable energy savings can be obtained by using natural rocks with low thermal conductivity in insulating the buildings. In this study, the amount of energy conserved by using porous tuff stone in external walls of buildings is calculated. It was shown that considerable energy savings can be achieved by using tuff stone for facing buildings in cold climate zones such as Isparta region. The cost of installing tuff stone panels for facing buildings will be paid back in four years by savings in heat energy.     

Longitudinal prediction of the operational energy use of buildings

Thus far most studies of operational energy use of buildings fail to take a longitudinal view, or in other words, do not take into account how operational energy use changes during the lifetime of a building. However, such a view is important when predicting the impact of climate change, or for long term energy accounting purposes. This article presents an approach to deliver a longitudinal prediction of operational energy use. The work is based on the review of deterioration in thermal performance, building maintenance effects, and future climate change. The key issues are to estimate the service life expectancy and thermal performance degradation of building components while building maintenance and changing weather conditions are considered at the same time. Two examples are presented to demonstrate the application of the deterministic and stochastic approaches, respectively. The work concludes that longitudinal prediction of operational energy use is feasible, but the prediction will depend largely on the availability of extensive and reliable monitoring data. This premise is not met in most current buildings.     

Impact of constructional energy‐saving measures on radon levels indoors

Energy‐efficient building refurbishment has the aim of saving energy and thus reducing CO₂ emissions. Increased energy efficiency of a building often implies reduced air exchange. Together with other indoor air quality problems, this may lead to an increase in indoor radon concentration (Rn‐222). In order to investigate the extent of this problem, measurements of radon concentration in energy‐efficient refurbished and low‐energy houses (passive houses) were carried out. Track etch detectors were exposed in each type of building over a period of 1 year. A reference sample of non‐refurbished non‐passive buildings was drawn from the National Radon Database for comparison. Buildings were selected that have the same radon relevant properties and were built on comparable geological subsoil like those investigated. The reference sample was compiled in such a way that the measured values from the rooms on the ground floor of the refurbished and passive houses were each assigned a measured value from the database. The statistical analysis shows that the houses refurbished for energy efficiency have a wider distribution of radon concentrations indoors than the non‐refurbished ones. Both the mean value and the median of the radon concentration have nearly doubled in buildings refurbished for energy efficiency. The difference is statistically significant. On the other hand, there is no significant difference between the distributions of passive houses and houses not refurbished for energy efficiency.     

Energetischer Wärmeschutz versus hygienischer Wärmeschutz – Sind die derzeitigen Auslegungsklimate für den winterlichen Wärmeschutz geeignet zur Beurteilung der Schimmelpilzgefährdung alter und neuer Bausubstanz?

Energy aspects vs. hygiene aspects of thermal insulation. Are current design criteria for thermal insulation in winter suitable for assessing mould risk in older and new buildings? Determining minimum surface temperatures in affected areas with the aid of thermal bridge calculations is an important basis for analysing mould growth. According to the generally recognised state of the art, calculations are usually based on steady‐state conditions and design data for minimum thermal insulation requirements in winter. This article initially explains the origins of these boundary conditions in the field of thermal insulation and current options and requirements for assessing calculation results. The article then illustrates that, contrary to the conventional view, the “cold, dry” boundary conditions currently used do not necessarily represent the worst case of external climate conditions that can be expected. The authors suggest that the boundary conditions for the calculations should be amended, so that less favourable “mild, damp” external conditions during spring and autumn can be taken into account. Suitable approaches are proposed.     

寒区近零能耗建筑能耗分析

严寒和寒冷地区冬季对化石能源需求量较大,“近零能耗建筑”是我国降低采暖能耗的有效途径.我国之前主要参照德国被动房的设计规范,但严寒和寒冷地区与德国的气候并不完全相同.文中利用DeST建立寒区居住建筑和办公建筑模型,以哈尔滨、沈阳和北京为代表城市,对基准建筑和“近零能耗建筑”进行模拟,结合中德两国近零能耗建筑技术标准,进...     

The impact of zoning regulations on thermal comfort in non-conditioned housing in hot,humid climates: findings from Dhaka,Bangladesh

In parts of the developing world where densities are high but the availability of air conditioning is limited, building massing and height regulations can influence interior comfort levels. Dhaka, Bangladesh, is characterized by high population densities, a lack of open spaces, and high poverty levels, combining to produce living conditions which are not only uncomfortable, but may lead to the spread of disease. A recent change in zoning regulations provides an opportunity to assess the success of building heights and setbacks in improving indoor thermal comfort conditions. We assess the impact on thermal comfort within Dhaka’s non-conditioned apartment buildings of four zoning schemes which differ in their specifications for setbacks, maximum buildable area, and building heights; but that maintains the current density. Computer simulation techniques model the buildings to test solar, daylight, and ventilation inside the central building to calculate resultant indoor temperature, mean radiant temperature, relative humidity and air velocity. Comparison between these values helps to determine which zoning schemes produce the most favorable thermal conditions. Findings suggest that zoning schemes that provide better solar protection and better natural ventilation are able to reduce indoor temperature and increase indoor air velocity over that provided by current zoning regulations. Recommendations for revising current zoning regulations are given along with general recommendations for how buildings in hot, humid climates can maximize passive cooling, encouraging energy savings and environmental sustainability.     

节能建筑中热桥对供暖负荷和能耗指标的影响

作者用所编制的计算机程序对嵩山节能小区内各建筑物的热桥节点做了详细计算，发现热桥不仅对能耗指标和供暖热负荷影响甚大，而且对不同构造的建筑物的影响大不相同。在传统４９０砖墙的建筑物中，热桥的附加值只占按一维传热计算的５％￣７％，而在砖与岩棉的复合外墙中，却占到２０％以上。     

Life cycle cost implications of energy efficiency measures in new residential buildings

The importance of the built environment from an environmental impact and energy use perspective is well established. High thermal efficiency of the constructed building envelope is a key strategy in the design and construction of buildings which limit use of active space conditioning systems. Australia's current housing stock is thermally poor and national energy performance standards are relatively weak when benchmarked against international best practice. A lack of data has impeded the policy debate and a significant gap in analysis remains a lack of empirical research into the life-cycle cost implications of increased building thermal efficiency, particularly for residential buildings. This paper applies an integrated thermal modeling, life cycle costing approach to an extensive sample of dominant house designs to investigate life cycle costs in a cool temperate climate, Melbourne Victoria. Empirical analysis provides new insights into lifetime costs and environmental savings for volume housing design options and identifies sensitive factors. Results suggest that the most cost-effective building design is always more energy efficient than the current energy code requirements, for the full time-horizon considered. Findings have significant policy implications, particularly in view of present debates which frequently present higher energy efficiency standards as prohibitive from a costs perspective.     

Identification of key factors for uncertainty in the prediction of the thermal performance of an office building under climate change

There is growing concern about the potential impact of climate change on the thermal performance of buildings. Building simulation is well-suited to predict the behaviour of buildings in the future, and to quantify the risks for prime building functions like occupant productivity, occupant health, or energy use. However, on the time scales that are involved with climate change, different factors introduce uncertainties into the predictions: apart from uncertainties in the climate conditions forecast, factors like change of use, trends in electronic equipment and lighting, as well as building refurbishment / renovation and HVAC (heating, ventilation, and air conditioning) system upgrades need to be taken into account. This article presents the application of two-dimensional Monte Carlo analysis to an EnergyPlus model of an office building to identify the key factors for uncertainty in the prediction of overheating and energy use for the time horizons of 2020, 2050 and 2080. The office has mixed-mode ventilation and indirect evaporative cooling, and is studied using the UKCIP02 climate change scenarios. The results show that regarding the uncertainty in predicted heating energy, the dominant input factors are infiltration, lighting gain and equipment gain. For cooling energy and overheating the dominant factors for 2020 and 2050 are lighting gain and equipment gain, but with climate prediction becoming the one dominant factor for 2080. These factors will be the subject of further research by means of expert panel sessions, which will be used to gain a higher resolution of critical building simulation input.