Effects Of Low Energy Architecture On Building Cost Within The Scope Of Economic Feasibility Studies

Abstract

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1996Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 1996Ekolojik dengeyi korama ve doğal kaynaklan hesaplı tüketme zorunluluğu, yapının tasarlanma ve inşaası aşamalarında karar vericileri yeni tedbirler almaya yöneltmektedir. Bu amaç için yapının ekonomik ve teknolojik olarak yapılabilirliğinin mümkün olması gerekir. Bu çalışmada, özellikle petrol krizi sonrası, dünyada artan bir ivmeyle kabul gören Düşük Enerji Mimarlığı Yaklaşımının ekonomik yapılabilirlik çalışmaları kapsamında maliyete etkileri irdelenmektedir. Ekonomik Yapılabilirlik Çalışmaları Kapsamında Düşük Enerji Mimarlığı Yaklaşımının Maliyete Etkisi konusu; Giriş, Düşük Enerji Mimarlığı, Fizibilite ve Düşük Enerji Mimarlığı Yaklaşımının Bina Maliyetine Etkileri olmak üzere dört bölümde incelenmiştir. Giriş Bölümü'nde problemin tanımı yapılmış ve araştırma metodolojisi özetlenmiştir. Düşük Enerji Mimarlığı Bölümü'nde, kuramsal ve tarihi gelişim ile araştırma kapsamında, yerleşim ölçeğinden malzeme seçimine dek dizayn ve imalat kriterleri tariflenmiştir. Fizibilite Bölümü'nde, kuramsal ve tarihi gelişim ile Fizibilite kapsamında yapılan çalışmalar teknik, örgütsel ve ekonomik değerlendirme bazında ve herbirinin alt açılımlarından bahsedilmek suretiyle tariflenmiştir. Dördüncü Bölüm olan, Düşük Enerji Mimarlığı Yaklaşımının Bina Maliyetine Etkileri, ikinci ve üçüncü bölümlerde tariflenen konuların çakışma noktasında, ve araştırmanın amacı doğrultusunda yer verilen değerlendirmelerden oluşmaktadır.The value to the user of any building resides its ability to promote well-being and encourage people to perform at their best. For designers to meet this challenge requires a proper response to the findings of many studies. Architecture is a process; the art and science of designing buildings and also a product; the buildings that this design process creates. Architecture therefore embraces the design process, the construction process, the building as it is intended to be used, and the building as it actually performs and used in practice. All buildings require energy inputs at various points in their life cycle. The amount, type and uses of energy vary across buildings, regions and countries. In general, combustible fuels and electricity are supplied for lighting and equipment, cooking, hot water, heating and cooling, and mechanised access. Other energy inputs are derived as incidental heat gains from these services, from the sun and from people. Solar radiation in particular can make significant contributions to heating, cooling and lighting loads. In "low energy buildings" designed to minimise energy consumption, these incidental gains can meet %70 of the total energy needed. Energy efficient design embraces the design and building process, the building as it is intended to be used, and the building as it is actually used. Energy efficient design therefore priorities' energy efficiency for human factors, the environment, economics, architecture, building elements, solar applications and monitoring. Energy efficient design demands an exchange of energy conscious information among designers, building managers and users. This exchange can occur at two levels; Short- term feedback at local level, and long-term feedback at global level. VIII One of the main functions of a building is to create an environment that is less varied and therefore more usable than that outside. Energy efficient design enables this system to be controlled from the perspective of energy efficiency. It gives buildings the ability to control energy gains, losses and demands, and gives users the ability to control energy gains, losses and demands, and give users the ability to control the building and its technology. Energy efficiency is also affected by the characteristics of the services within the building. The technology selected for these services should be appropriate for context, cost, function and use, and should be capable of being installed, operated and maintained without undue difficulty. In terms of an overall strategy, energy efficient design also provides a feedback loop for designers to understand and act upon the consequences of design decisions, and to design in more control. An energy efficient design strategy therefore embraces the whole project, including design and construction process, intended use and actual use, all within a responsive and functionally appropriate environment. Through energy efficient design, economic savings are made in the energy consumed during a building's life. Because running costs are lower than for a conventional building, after a period of time any extra design and construction costs are recovered. Savings are than made in running costs for the rest of the buildings life. A short payback period therefore means greater cost effectiveness. New buildings should only be constructed where there is sufficient purpose. More energy can be consumed as a result of building location and operation. Free solar energy is relatively easy to obtain, even at northern latitudes. The problem for designers is to make sensible use of it inside the building. A building should not waste energy by being over-sized or inefficient in the use of space. In addition energy savings may be provided by controlling the design of the building fabric, materials and elements. Running costs for services can be reduced by using efficient systems and good control equipment which is conveniently located, easy to understand and not too complex can repay its costs within a few years. Management can be effective in new and existing buildings. Installing control equipment and providing user training in its use can produce savings of over 25%. For example, a reduction of 1°C in the average temperature levels can often save 5% of the midwinter heating cost and up to 10% of the annual heating cost. IX The most important factors influencing energy-efficient design are, the location of the building, positioning on site, the direction it faces, arrangement of internal rooms, building size, building type, building function, the primary structure, construction methods, material specification, the building in use and legal obligations for the designer and building. Each of the above parameters are explained from the perspective of energy-efficient design to allow new designs to be explored and existing designs to be verified for energy efficiency. The design of individual components and building details may then be undertaken with a full understanding of the larger energy efficiency framework. Capital is needed to design and builds a building. Energy efficient buildings often cost more to design and build. The size of this overcost differs between countries, buildings and designs. In general, overcosts average 10% of design and construction costs within a range of 1 0-15%, and are lower for designs using conventional construction, materials and technology. Finance of overcosts may come from a number of sources. Building clients and designers may bear overcosts, governments at all levels may finance overcosts, particularly for programmes such as the use of insulation. Professional Institutions may finance designs which promote the profession. Private sector manufacturers and commercial interests may finance overcosts where designs demonstrate the value of their products or services. Such as private patrons, financial institutions, charities and development agencies may finance the over costs. In addition to the finance one of the most important item for the feasibility of the building is the payback period. The payback period is the time it takes for the overcosts of enrgy-efficient design to be repaid as reduced running costs. For long- life measures, such as increased insulation, a payback period of 10-20 years may be considered reasonable. Shorter life measures such as mechanized shading devices, need to pay for themselves more quickly. The most important running costs are energy, maintenance and improvement, life expectancy and added value. The amount and cost of energy consumed is the main determinant of running costs. Lower energy consumption and rising energy prices means relatively lower running costs compared with conventional buildings, and therefore shorter payback periods. Designs for conventional construction, materials and technology, such as exploiting orientation for solar radiation and light, require less attention. Complex technology İs often less successful; for example, mechanical ventilation systems with heat recovery and movable shutters can lessen energy efficiency or fall if badly maintained. As many energy-efficient buildings are experimental or one-off designs, allowance must be made for higher maintenance levels and improvements. The payback period should usually be less than half the expected overall life of the measure. High replacement costs of building elements and solar applications also add to running costs and mean longer payback periods. Positive factors which cannot be easily costed should also be considered; for example, sunspaces raise internal quality, amenity and property value. Feasibility studies represent a decision making approach with a long history. Through the techniques still require refinement they offer a systematic approach to establish the likely outcome of decisions and the costs involved. Through these predictions about the future are by no means certain, their usefulness lies in the hope that the results may be nearer to expectations if they are based on an objective assessment of the costs and benefits of a scheme rather than if decisions are based purely on intuition, then the exercise may be said to be worthwhile undertaking. Moreover using cost benefit analysis, it's possible to relate detailed analyses of building costs to complex notional costs which might only arise in the far distant future. With the increasing awareness of environmental and ecological problems that are accumulating in the world at an alarming rate, it is likely that building projects with expected useful lives of 50 to 100 years must begin to anticipate some of these future implications, especially those relating to energy use and pollution as well as the consumption of diminishing raw material resources. In this thesis not only the economic feasibility but also all design levels and prefeasibility of probable subsystem alternatives to build a low energy building has discussed. The main structure of the investigation consists of four chapters, named introduction, the definition of low energy building, feasibility studies and economic feasibility of low energy buildings. XI At first chapter the problem undertaken in the thesis is defined. Then the early studies carried on Turkey and at abroad about the problem is briefly explained and the objectives of the research are stated with its scope and limitations. In addition to the definition of the problem, the method of investigation is explained. The investigation results are based on scanning literature, lessons of the construction management programme of ITÜ, Architecture Faculty, practice at design and construction of low energy buildings at Frankfurt in Germany, interviews with the specialists working both at Turkey and Germany and examining the world-wide publications. The second chapter is devoted to a full analysis of the Low Energy Building's aspects, design criterias, building materials and subsystems. At the third chapter the history and the limitations of Feasibility Studies are defined. The subject is observed in three sections; Technical analysis, Organizational analysis and economical analysis. The fourth chapter; Effects of Low Energy Architecture Approach on Building Cost expresses the importance of energy expences on building investments and the prefeasibility studies and sampling the world-wide applied Low Energy Buildings within the scope of building performance. As a result of the thesis, an approach have been stated which could be used as a check-list during the design prossesses and feasibility studies. According to this statement the 15% additional cost used to promote the performance of a building can provide 70% energy saving which could also be paid back by the reduction of maintenance and running costs.Yüksek LisansM.Sc

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