ISVS-­‐6 th
6 International Seminar on Vernacular Settlements, Contemporary Vernaculars: Places, Processes and Manifestations, April 19-­‐21, 2012, Famagusta, North Cyprus. ISVS-­‐6 – Climate & Comfort: LOCATION Hanspeter Bürgi, Sonja Huber Competence Centre for Materials, Structure and Energy in Architecture (CC MSE A), Focus Energy Lucerne University of Applied Science and Arts – School of Engineering & Architecture, Lucerne, Switzerland Abstract The research project “Climate & Comfort: LOCATION” (Klima & Komfort: ORT) studies the problem of globally conceived energy targets such as the 2000-­‐Watt society and their local implementation. Today’s energy policy focuses strongly on reducing energy consumption in industrialised countries. Concurrently, the need for action in developing countries, which still have low energy consumption levels, requires study. Their energy consumption will rise quickly due to steadily growing industrialisation and simultaneously increasing comfort demands. Low-­‐energy construction methods are investigated by precisely studying vernacular buildings in two different cultural environments with similar geographic and climate conditions – Switzerland (Alps) and Bhutan (Himalayas). Realising the fact of finite resources, current architectural developments face similar questions to those faced by vernacular architecture. Therefore above all vernacular buildings often show clever and simply implemented principles for a low-­‐energy construction method. The research work studies and adapts these vernacular approaches so they can be implemented in locally and culturally related architecture (new vernacular architecture). In this way, the principle of the central stove that heated several rooms can be adapted and applied as a “Thermo Space”, which is comparable with a voluminous stove in a central location in the building. Room units requiring high temperatures, such as sanitary facilities, can be integrated into that central core and directly heated. The solid construction method allows the thermo space to store heat and pass it on to surrounding rooms. In the study “Climate & Comfort: LOCATION”, such principles are researched further and defined in concrete to allow their global application both in industrialised and developing countries. Targeted adaptation to local climatic, technical and cultural conditions thereby becomes concretely feasible. Different regions can learn from each other and use global exchange to plan locally appropriate advances: “think global, act local”. Keywords: Sustainability and energy focus, global principle and local implementation, locally and culturally related architecture Hanspeter Bürgi, Sonja Huber Introduction The theme of energy efficiency is and will remain an increasingly important factor in contemporary architecture. Especially in Europe, hardly a building can be constructed without carefully taking its energy consumption into account. A turnaround in energy policy, which is becoming especially apparent through initial international framework conditions as the 2005 Kyoto Protocol comes into effect, demands constantly new developments for energy-­‐optimised construction methods. Laws, guidelines and labels have led to a reduction in energy consumption in the field of buildings. Targets such as the 2000-­‐Watt society aim their strategies on a global level, which is why we intend not only to concentrate on industrialised countries when addressing the question of energy efficiency, but also look at emerging and developing countries. They currently have relatively low levels of energy consumption. But as they close the development gap and their energy demands grow, these regions experience rapid rises in energy consumption. High demands for levels of comfort in our society significantly contribute to excessive energy consumption. This is the very reason for today’s special emphasis on further technological developments. High-­‐tech solutions, for instance to create or recover heat, or solar power generation, are constantly being researched. In our research work, we intend to focus on low-­‐
tech systems and seek solutions that use predominantly architectural and typological approaches to achieve energy-­‐optimised, economic construction methods. Question The question of how our society’s energy consumption can be reduced in the long term is addressed on many levels. Since the energy consumption of buildings makes up a very large proportion of a population’s overall energy consumption – in Switzerland buildings require around 50% of all energy consumption and create 40% of total CO2 emissions – there is a great need for the construction industry to react [7]. In numerous European countries, targets for energy-­‐efficient buildings were formulated, labels and certification systems were launched and state subsidies were institutionalised. In the case of Switzerland, the multi-­‐level Minergie label introduced in 1998 and the 2000-­‐Watt society target advocated by Novatlantis since 2001 are worth mentioning in this respect. 2000-­‐Watt society, global and local The globally envisaged goal of a 2000-­‐Watt society aims at the fair distribution of energy resources for the entire world population by 2150. With respect to today’s limited energy resources, the targets address energy consumption as an answer to advancing climate change, as well as emissions values. From a global perspective, 2000 Watt is already the current average energy requirements of one person. In the long term, the aim is to reduce the current 6500 Watt requirements in industrialised countries to 2000 Watt. At the same time, the demand from developing countries, which is currently 500 Watt, should not grow beyond the target value (Figure 1). A further aim is minimising CO2 emissions to one tonne of CO2 per person. Both intentions go hand in hand and especially require replacing fossil fuels with renewable energy resources, as well as a significant reduction in overall energy consumption [8, 9]. ISVS-­‐6, April 19-­‐21, 2012, Famagusta, North Cyprus Figure 1: Per capita energy requirements: Developing countries – World – Industrialised countries [9] Technical advances and architectural intervention The period since 1950 has brought industrialised countries great technological transformation. The introduction of central heating and air conditioning systems seemed to solve all heat-­‐related problems in buildings, regardless of the location and climate situation. At the same time, initiated by advanced technological solutions, public demand for comfortable living rapidly increased. This interaction accelerated the increase in the consumption of resources and CO2 emissions. The stringent energy targets of new buildings today are above all achieved through technical advances. For instance high performance insulation, new sources of energy, heat distribution systems and controlled ventilation with heat recovery are common solutions. However these approaches are also cost-­‐intensive factors and are therefore rarely used in developing countries. Furthermore, the international sale and distribution of technical advances beyond local regions also encourages the loss of locally anchored and culturally-­‐related construction methods. Vernacular architecture – one that is connected to its location and develops out of a specific culture – is increasingly disappearing. Aim of the research work To implement energy targets such as the 2000-­‐Watt society, it is necessary and interesting to seek simply implementable solutions approaches in addition to technical means. They allow an energy-­‐optimised construction method and can be cheaply applied both in industrialised and developing countries. Instead of devices that optimise the energy balance of a building, the aim is to find constructive, spatial and architectural approaches. In the first phase of the research project, vernacular buildings in the mountainous regions of the Alps and the Himalayas are comparatively analysed. Like earlier examples of vernacular buildings, their initial situation today and the question of limited energy resources are similar. Vernacular architecture requires exact knowledge of the local conditions and is characterised by the adapted, economic and simply implemented principles of a construction method that uses materials and energy sparingly. Further study picks up on these principles and formulates them in a way that makes them both globally applicable and adaptable in a targeted way to local climatic, technical and cultural conditions. They should lead to a vernacular architecture – one that fulfils energy targets, while also being economically and culturally feasible, as well as being developed in a locally specific way. Hanspeter Bürgi, Sonja Huber Method and research Research work is based on the exact analysis of the idea of comfort in both mountainous regions of the Alps and the Himalayas. These are then compared with global energy targets in order to determine target conflicts and the need to act. In-­‐depth research of vernacular buildings in both mountain regions also reveals locally and culturally specific principles of original construction methods. Current research at the Lucerne University of Applied Science and Arts The study “Climate as a Design Factor” was published in 2009 as part of previous research work by the CC MSE A [3]. Complementary to the publication, which studied the external influences on the energy management of a building, the research work “Climate & Comfort: LOCATION” will address the theme from inside a building outwards. In late 2009, underlying principles were developed in the CC MSE A and supported by a field study in the Himalayas in Bhutan, as documented in the status report entitled “Climate and Comfort – Energy and Buildings: basic (1)” [4]. It discusses the effects of climatic influences and changed comfort demands for the building shell and building technology using the case study of Bhutan. Leading on from that, the MA course in Architecture “A house in the Alps – A house in the Himalayas: Continued construction in contrasting cultural contexts, focusing on energy” was held in the autumn semester of 2010. The students analysed and compared vernacular and modern buildings in the Alps and the Himalayas, developing architectural projects for both regions based on the insight gained from the analysis [5]. Figure 2: Alps, Himalayas and other mountain regions (basis in [10]) ISVS-­‐6, April 19-­‐21, 2012, Famagusta, North Cyprus The idea of comfort compared to energy targets Building on the already existent studies, the research project will study the term “comfort” using the two climatically and topographically similar mountainous regions of Switzerland and Bhutan. Similarities and differences with respect to demands for the level of comfort from the two regions’ users, the causes of such differences and the contrasting implementation methods they require in the building are all aspects of study. Themes such as room temperature requirements, use and occupancy, as well as hot and cold water requirements, are interesting aspects to study. For instance, if one studies room temperature requirements in both cultures, there are clear differences. Demand for a uniform temperature in all rooms of one’s home was established after the introduction of central heating in Switzerland. In Bhutan, such temperature demand is much more differentiated and use-­‐specific. Instead of comprehensive floor-­‐heating, which even heats auxiliary rooms and storerooms, only selected rooms where people spend long periods of time are heated using individual devices. So a direct correspondence between the relevant comfort demands, the heating and cooling devices used and therefore the energy consumption is evident (Figure 3). Based on these studies, the idea of comfort can be grasped as an abstract demand with effects on architectural, spatial and infrastructural implementation. The conclusions can be used as a basis for studying a building and its energy balance from inside out. Figure 3: Switzerland: Comprehensive room heating, Bhutan: Heating for selected rooms The conclusions of the study on comfort demands and their relevant local implementation can be compared with the global energy aim of a 2000-­‐Watt society. The comparison determines concrete target conflicts both in existing buildings and in future construction trends, as well as the need for action in the relevant regions. The study includes qualitative and quantitative aspects (e.g. energy and life cycle assessment). For instance the question arises whether defining a minimum requirement for building shells is the only correct approach with respect to low heating requirements, or whether greater attention to the relationship between heated and unheated surfaces, i.e. minimising the heated perimeter, could also be a useful. Analysing vernacular types of architecture Together with the study of the idea of comfort on a social, historical and sociological level and its implementation, case studies of vernacular buildings in Bhutan and Switzerland are also investigated. Floor plans and sectional analyses provide information on temperature-­‐dependent typological disposition and the distribution of heating energy, as well as passive heating. The construction method, material, construction types and energy-­‐relevant elements were also manually implemented in intensive analytical study as part of the 2010 Architecture MA course using building models. Hanspeter Bürgi, Sonja Huber One example of such studies is presented here: the Haus Dellenstein in Engelberg in the central Swiss Alps (which was originally constructed in the 15th century). The building has three storeys. A solid soapstone stove heats the living rooms on the middle floor. Due to its stone construction, it also acts as a heat store that gives off warmth long after the stove fire extinguishes. The stove is positioned centrally in the building and adjoins with two rooms that it also heats. Separated by a central corridor, the building’s kitchen and auxiliary rooms are situated to the rear. The bedrooms, which require a lower temperature, are situated directly above the heated rooms and are only warmed by the rising heat via ceiling apertures and the warm chimneys. The cellar area is underground on the slope side. It thereby remains cool even on warm summer days, allowing it to be used for storing foodstuffs such as cheese. The cellar combines with the unheated roof structure and the partially covered balconies at the side to create a climatic buffer zone around the warm rooms, thereby reducing external heat-­‐loss. (Figure 4). Figure 4: Haus Dellenstein in Engelberg, Switzerland (basis in [2]) An example of a vernacular building in the Punakha Valley, Bhutan (which was built in the late 19th, early 20th century) shows typological principles that are related to those in the Haus Dellenstein. Instead of having a central stove that heats several rooms, this building only heats one central room. It serves both as a kitchen and a living room and is situated directly above the stables to benefit from the heat produced by the animals. Unlike the Haus Dellenstein, where the living room is integrated into a regular floor plan structure, the living room in Bhutan is constructed massively and forms the centre of the building. Auxiliary rooms are aligned around the core in a light construction method, thereby benefiting from the heat emanating from the core and also acting as an insulating layer (Figure 5). Figure 5: Rural House in Punakha Valley, Bhutan (basis in [6]) When analysing such vernacular buildings, it is noticeable how certain principles of spatial and energy phenomena are repeated in both mountain regions. Naturally, differences due to the relevant regional, social and cultural context remain definitive with respect to the material, constructive details and in some aspects the typological and design expression.
ISVS-­‐6, April 19-­‐21, 2012, Famagusta, North Cyprus Implementation A second phase of research work seeks synergies in the principles of different cultures on the basis of the analysis. Building upon this, concepts for energy-­‐optimised construction methods are formulated that can be applied globally. In order to develop a new form of vernacular architecture in the sense of locally and culturally related architecture, implementation examples are presented as prototypes together with their relocalisation and cultural integration. Synergies between different cultures and global concepts The studied vernacular approaches reveal synergies between the different regional construction cultures. Often, related principles, such as the two above-­‐mentioned temperature-­‐related typological dispositions, are implemented in slightly different ways. In-­‐depth analysis, including typological aspects, technical construction details, constructive solutions and building technology developments in vernacular buildings, is complemented by the study of buildings as they are currently used, and today’s technical solutions. Insight from both regions can interact with architecture and technical innovations to develop globally applicable concepts for a sustainable construction method. They represent general principles that can be applied globally in their present form and contain both aspects of architecture and construction technology: including the building technology, the building shell and spatial, typological solution approaches. In the 2010 autumn semester of the Architecture MA course, four initial theses were established, which serve as examples for such global concepts: “Polar Compact”, “Thermo Space”, “Climate Zone” and “Solar Active”. These theses represent a typological process for related systems and each include several related principles. The “Polar Compact” thesis addresses the form factor of a building and its implantation into the terrain. For instance the relation between the façade surface and the volume can be minimised by adapting the building volume to a compact optimum, thereby significantly reducing the building’s heat-­‐loss. When studying vernacular buildings, it becomes clear that the building is usually constructed in a very compact way, often with an almost square ground plan and similar proportions in the height of the building. In applying such a principle, the influence of context on the building is often especially strong. Although the form of a circle is mathematically the most efficient form, it can very often only be partially implemented out of respect for the existing urban structure. Other aspects within the “Polar Compact” thesis are therefore also highly significant in addition to the building’s shape. The structural design of the building shell and integration into the terrain can decisively influence the heat balance of a building. The earth only adopts the temperature fluctuations of the outside air in a reduced way. Constructing targeted parts of the building underground can keep them cool in the summer and warm in the winter. So no additional energy consumption is required for cooling in the summer and heating requirements are reduced in the winter (Figure 6). Figure 6: “Polar Compact”: Form factor, building shell, reference to terrain Hanspeter Bürgi, Sonja Huber The thesis of a “Thermo Space” draws on elements of typological disposition described in the previous chapter. For instance it includes the principle of a central room in the heart of the building, with a massive construction method, to act as a heat store and heating element. It is the only heated room. All room units requiring lower temperatures are aligned around this central room and warmed by the heat lost from the central room. Questions of comfort requirements are decisive for the effectiveness of the concept. Studies of individual room units and their room temperature show that such a room would not act as a living room today, as used to be the case in vernacular buildings. Today, bathrooms for instance are integrated into the building. They are rooms with high temperature requirements and are predestined for central locations. Following similar principles, such thermo spaces can be applied on a smaller scale. That means that specific uses could disappear as a result and the massive heat source could be reduced to a single hypocaust heating unit integrated into a central wall or a storage mass with heat radiation (Figure 7). Figure 7: “Thermo Space”: Heating core, hypocaust heating wall The “Climate Zone” thesis is also based on the thermally dictated typology. The individual room units of a typology are studied to determine the required room temperature and then grouped and aligned in the floor plan. Warm rooms are thereby individually heated to the temperatures they require, while cooler rooms can act as an insulating layer against the outside space. The “Climate Zone” thesis can be applied to the entire floor plan to develop a thermally optimised typology. To do so, the warmest rooms are situated at the centre of the building and rooms with lower temperature requirements are located around the central rooms to form an insulating mantel. A natural temperature development from the centre of the floor plan to the outside is thereby achieved, keeping heating requirements to a minimum. The thesis can also be applied in a reduced form to specifically selected zones of the floor plan. For instance a voluminously designed window can create a transitional climate between the inside and outside, thereby fulfilling the task of a partially usable buffer zone. Atria and conservatories can similarly form a transition zone and, in addition to acting as an insulating layer, can also be used for solar power generation (Figure 8). Figure 8: “Climate Zone”: Thermally optimised typology, voluminous window, atrium The fourth thesis, “Solar Active”, stems from constructive considerations. It includes active construction elements and components that are used to generate energy and solar power. For ISVS-­‐6, April 19-­‐21, 2012, Famagusta, North Cyprus instance this thesis was used to develop the prototype for a wall construction that acts both as a thermoactive construction element and as room ventilation with preconditioned external air (student: Reto Meier MA course, Architecture 2010). The structure is derived from traditional clay construction methods and consists of a wall element in three layers. The clay wall has a dark exterior colour and is enveloped again by an air space and glass. The sun shines through the glass and warms up the clay wall, which stores the warmth in the form of latent storage and can pass that heat on to the interior space in an out-­‐of-­‐phase cycle. Targeted openings both in the clay and glass layers allow the interior of the building to be directly heated or ventilated as required using the thermoactive component. On its way from the outside to the inside, the air streams along the wall that has been warmed by the sun and is already conditioned on arriving inside the room. Depending on the region of the construction site, the clay wall can be replaced by a local, solid construction material. The thesis can also include similar constructions and be combined with technical innovations (Figure 9). Figure 9: “Solar Active”: Thermoactive wall construction (prototype: Reto Meier) These theses were presented and critically examined during a continuing education course for the humanitarian aid staff of the Swiss Agency for Development and Cooperation (SDC) in the autumn of 2011. Participants, who work in many different regions of the world, especially stressed the costs that material acquisition entails and the time pressure in the case of reconstruction following disasters to be problems of energy-­‐optimized construction methods in developing countries. At the same time, acceptance by the public towards new building methods was often a central problem. It highlights the importance of localising globally conceived concepts. Local prototypes for a new vernacular architecture The globally applicable concepts form a basis that can be used in many areas with the same climatic conditions: in high-­‐technology countries such as Switzerland, but also in Bhutan and other emerging and developing countries. The development of prototypes that can be locally implemented demonstrates possible application and acts as an example for numerous further locally specific applications – always with the aim of a global energy policy under local conditions. So starting with global concepts, the focus moves to regional localisation. The above mentioned concepts are developed further into locally implementable prototypes and elements, taking the local architectural culture and social and cultural aspects, as well as technical and economic possibilities into account. Examples of a new vernacular architecture are developed by integrating local conditions such as standard construction methods, local craftsmanship and sensible application of locally available materials. One good example of localising and applying such global concepts was shown by a project presented in the MA course in Architecture in 2010, which studied Engelberg in Switzerland Hanspeter Bürgi, Sonja Huber (student: Juliane Reuther). In Engelberg, an Alpine climate dominates with an average annual temperature of just over 5 °C. The project combined results from the theses “Polar Compact” and “Climate Zone” and particularly addresses the thesis “Thermo Space”, due to the massive core at the centre of the building. Individual pellet stoves and cooking niches are directly integrated into the concrete wall of the core and heat the entire core using warm air circulation, which is integrated into the solid walls in a similar way to a hypocaust heating system. This central stove core forms the only heating element in the building. Sanitary rooms, which have the highest temperature requirements due to the nature of their use, are organised inside the warm walls, allowing them to be directly heated. The surrounding living rooms benefit from the heat loss of the core (Figure 10). Figure 10: Central heating core with pellet stove and heat distribution (project: Julia Reuther) According to the “Climate Zone” principle, rooms with functions requiring low temperatures are organised around the outer shell. Traditional covered walkways and storerooms form a kind of buffer zone, an insulating layer between the living rooms and the exterior space. The outer design and construction pays great attention to applying regional craftsmanship and local materials. The upper floors are finished in wood upon a solid base, as is usual for the traditional construction methods of the region. A wooden frame construction can be developed in detail with local businesses using standard regional carpentry skills. The ceilings are made of concrete and act as heat storage mass (Figure 11). Figure 11: Floor plans, 2nd and 3rd floors and façade (project: Julia Reuther) Conclusion The results of research work to date clearly show similar principles of energy behaviour with respect to buildings in regions with similar geographic, topographic and climatic conditions. The analysis and interpretation of vernacular buildings, focusing specifically on energy, discussion in workshops and the application-­‐oriented further development of prototype concepts highlight ISVS-­‐6, April 19-­‐21, 2012, Famagusta, North Cyprus their great relevance. Actual localisation – i.e. the search for regional architectural approaches and cultural connections, for precise local placement – has a special significance. Without a reference to a location that thereby strengthens its identity, even the cleverest concept is hardly feasible. If however the wealth of local and simultaneous global principles is applied in a way that is relevant to the situation, real added value can be achieved. Adaptability demands a high degree of open systems and concepts. This especially applies to economic aspects if implementation is to be achieved both in highly and less industrially developed regions. Therefore robust, simple principles are required for quality, affordable solutions that are gentle on resources. A balance must be found between ecological, economic, social and cultural requirements: concrete sustainability. For instance initial case studies illustrate how traditional construction methods and techniques of craftsmanship can be intelligently combined with optimised high-­‐tech products used in a targeted way to create new overall systems. Locally related architectural approaches therefore – in combination with sensibly deployed, globally available technical solutions – uphold local cultures and strengthen their identities. References [1] Bürgi, H. Architektur-­‐Tradition. Tec 21: Bauen in Bhutan, Vol. 38 (2010), pp. 16-­‐19. [2] Kanton Obwalden, Inventar der schützenswerten Bau-­‐ und Kulturdenkmäler, 1992, R43 [3] Hönger, C., Brunner, R., Menti, U-­‐P., Wieser, C. Das Klima als Entwurfsfaktor, Quart Verlag, Luzern, 2009 [4] Bürgi, H. Klima und Komfort – Energie und Gebäude: basic (1) Dokumentation / Statusreport, Hochschule Luzern – Technik und Architektur, Luzern, 2010 [5] Bürgi, H., Herres, U.M. Weiterbauen in den Alpen und im Himalaya, Dokumentation, Hochschule Luzern – Technik und Architektur, Luzern, 2011 [6] Department of Works, Housing and Roads An Introduction to Traditional Architecture of Bhutan, Wah Meh Press Pte Ltd, Singapore, 1993 [7] Schweizerische Energiestiftung, 50% weniger Energieverbrauch im Gebäudesektor bis 2050, http://www.energiestiftung.ch (Januar 2012) [8] Novatlantis, Sustainability at the ETH Domain, Die 2000-­‐Watt Gesellschaft, http://www.novatlantis.ch (Januar 2012) [9] Fachstelle 2000-­‐Watt-­‐Gesellschaft, Die 2000-­‐Watt-­‐Gesellschaft, http://www.2000watt.ch (Januar 2012) [10] Konrad Weber, Geografische Projekte, http://www.reliefs.ch (Januar 2012) Hanspeter Bürgi, Architect ETH SIA FSU, Professor of Architecture, Head of energy focus at CC MSE A Sonja Huber, Architect EPFL, Scientific fellow at CC MSE A