Yaşam döngüsü enerji ve maliyet etkinliği açısından konut binalarının performanslarının değerlendirilmesinde kullanılabilecek bir yaklaşım
An approach for the evaluation of the residential buildings' performances in terms of life cycle energy and cost efficiency
Yazar: SUZİ DİLARA MANGAN
Danışman: PROF. DR. GÜL KOÇLAR ORAL
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Mimarlık Ana Bilim Dalı / Yapı Bilim Dalı
Derece: Doktora, 2015
Konu: Ekonomi = Economics ; Enerji = Energy ; Mimarlık = Architecture
Dizin: Ekonomik performans = Economic performance ; Enerji performans analizi = Energy performance analysis ; Fotovoltaik enerji = Photovoltaic energy ; Karbondioksit salınımı = Carbondioxide emission ; Çok katlı binalar = Multistorey buildings

Özet:
Günümüzde, küreselleşen enerji ve çevre sorunlarının hızlı ve maliyet etkin olarak çözüme ulaştırılması ve sürdürülebilir, ekonomik kalkınmanın sağlanması açısından enerji etkinlik düzeyinin geliştirilmesi, tüm gelişmiş ülkelerin enerji politikalarının odak noktasını oluşturmaktadır. Enerji etkinliği, giderek artan çevresel sorunlar karşısında çevresel gelişme ve ekonomik kalkınma arasındaki dengeyi koruyarak enerji, ekonomi ve çevre ile ilgili politikaların üretilmesini ve sürdürülebilirliğini önemli ölçüde belirleyen bir olgudur. 
Bu bağlamda, dünya genelinde tüketilen enerji ve enerji tüketimlerine bağlı CO2 salımlarından yüksek düzeyde sorumlu olan  konut binalarının enerji, ekonomik ve çevresel açıdan gösterdikleri performansın değerlendirilerek enerji tüketimlerinin azaltılmasına yönelik çözüm önerilerinin geliştirilmesi gerekli olmaktadır. Konut enerji performanslarının iyileştirilmesi ile konut binalarının enerji etkinlik düzeyinin artırılabileceği ve böylece önemli oranda enerji tasarrufunun sağlanabileceği bilinen bir gerçektir. Bu nedenle, tüm dünyada bina enerji performansının iyileştirilmesine ilişkin çalışmalar, hammaddelerin çıkarımı ve malzemelerin üretiminden binaların tasarım, yapım, kullanım ve bakım, yeniden kullanım ya da yıkım evrelerine kadar yaşam döngüsü içerisinde, binaların maliyet ekinliğinin de değerlendirilmesini hedefleyen ve dolayısıyla toplam ekonomik ve çevresel etki ve performanslarını dikkate alan bütüncül süreçlerin tanımlanması çerçevesinde gerçekleştirilmektedir. Özellikle, konut binalarının enerji performanslarının geliştirilmesine yönelik düzenlenen yasal mevzuatlar aracılığı ile her ülke kendi koşulları çerçevesinde uyulması gereken zorunlulukları belirlemekte, Türkiye'de de bu konuda çalışmalar yapılmaktadır. Bu çalışmalar kapsamında konut binalarında enerji ve maliyet etkin çözüm önerilerinin geliştirilmesi giderek artan enerji talebi ve enerji fiyatları göz önünde bulundurulduğunda, ülke enerji ekonomisi açısından büyük önem taşımaktadır.
Tez çalışması kapsamında, ülke kaynakları ve karar vericiler açısından optimum faydanın elde edilmesi hedefine yönelik konut enerji performansını iyileştirmede etkili olan önlemlerin farklı iklim bölgeleri için geliştirilmesi ve bu önlemlere ilişkin konut binalarının enerji, ekonomik ve çevresel performanslarının yaşam döngüsü çerçevesinde değerlendirilmesi amaçlanmaktadır. Bu amaç çerçevesinde geliştirilen yaklaşım;
•	yaşam döngüsü enerji tüketimi, CO2 salımı ve maliyetler açısından konut binalarında optimum performansın sağlandığı iyileştirme önlemlerinin ve
•	farklı iklim bölgeleri için uygun optimum iyileştirme kombinasyonlarının 
tanımlanmasını hedeflemektedir.
Bu hedef doğrultusunda, tez çalışması, altı bölümden oluşmaktadır. 
Bölüm 1'de tez çalışmasının önemi, kapsamı, amacı açıklanmakta, bu amaca yönelik yapılmış önceki çalışmalar ve yöntemler irdelenmekte ve tartışılmaktadır. 
Bölüm 2'de konutlarda enerji ve maliyet etkinliği tanımlanmakta, enerji ve maliyet etkinliğin belirlenmesinde etkili olan değişkenler açıklanmaktadır. 
Bölüm 3'te konutlarda yaşam döngüsü enerji ve ekonomik performanslarının değerlendirilmesine ilişkin kullanılabilecek "Yaşam Döngüsü Değerlendirme", "Yaşam Döngüsü Enerji", "Yaşam Döngüsü CO2" ve "Yaşam Döngüsü Maliyet" yöntemleri açıklanmaktadır.
Bölüm 4'te yaşam döngüsü enerji ve maliyet etkinliği açısından konut binalarının farklı iklim bölgeleri için optimum performanslarının değerlendirilmesinde kullanılabilecek yaklaşım açıklanmaktadır. 
Geliştirilen yaklaşımın başlıca adımları olarak,
•	referans konut binasının tanımlanması,
•	iyileştirme önlemlerinin tanımlanması,
•	referans konut binasının yaşam döngüsü enerji, ekonomik ve çevresel performanslarının değerlendirilmesi,
•	yaşam döngüsü enerji ve maliyet etkinliği açısından farklı iklim bölgeleri için optimum performans gösteren alternatiflerin belirlenmesi ve optimum iyileştirme kombinasyonlarının tanımlanması,
•	optimum iyileştirme kombinasyonlarının referans konut binasına göre yaşam döngüsü enerji ve maliyet etkinlik düzeylerinin belirlenmesi
adımları açıklanmaktadır.
Bölüm 5'te, geliştirilen yaklaşım çerçevesinde farklı iklim bölgeleri için ele alınan referans konut binasına ilişkin yapılan uygulama çalışması açıklanmaktadır. Çalışmada referans konut binası olarak Türkiye'de konut üretiminde etkin rol oynayan TOKİ tarafından inşa edilmiş, yaygın kullanılan yapım teknolojilerini ve tasarım kriterlerini barındıran mevcut bir toplu konut projesi ele alınmaktadır. Toplu konut uygulaması kapsamındaki konut bloklarından biri, referans konut binası olarak tanımlanmakta ve Türkiye'nin farklı iklim bölgelerini temsil eden beş ilde mevcut olduğu varsayılmaktadır. Böylelikle, yapılan uygulama çalışması sonucunda belirtilen amaca uygun olarak konut binalarının farklı iklim bölgeleri için yaşam döngüsü enerji ve maliyet etkinliği açısından optimum performanslarının değerlendirilebildiği ve optimum iyileştirme kombinasyonlarının tanımlanabildiği görülmektedir.
Bölüm 6'da, tez çalışması kapsamında elde edilen sonuçlar açıklanmaktadır.

Abstract:
Today, the speed and cost-effective solutions for globalized energy and environment problems and the improvement of energy efficiency level in terms of establishing a sustainable economic development constitute the basis of energy policies in all developed countries. The energy efficiency keeps the balance between environmental development and economic growth against great environmental problems. Therefore, it considerably determines producing policies of economy and environment and their maintainability. 
In this context, residential buildings are highly responsible for the energy consumed world-wide and CO2 emissions due to the energy consumption. Therefore, it is necessary to evaluate the energy, economic and environmental performance of residential buildings and to suggest solutions to reduce the energy consumption. It is a well-known fact that improving building energy performance may increase the energy efficiency level of residential buildings; so a significant amount of energy saving could be provided. The studies regarding building energy performance are carried on worldwide within the framework of defining integrated processes aiming to evaluate the cost efficiency and also considering total economic and environmental affect and performance of buildings during the life cycle from raw material extraction and material production to the building design, construction, use and maintenance, reuse or demolition stages. Especially, each country determines own obligations by legal regulations with regard to the improvement of energy performance of residential buildings.  
Turkey carries on the studies regarding improvement and application of legislations considering the responsibilities to be met because of being a party of United Nations Framework Convention on Climate Change (UNFCC) (2004) and Kyoto Protocol (2009) and an EU candidate country. Under the light of these studies, it is possible for Turkey to maintain the energy and environment policies by means of increasing the energy efficiency in all sectors. In terms of the national strategic goals such as providing the security of energy supply, environmental protection, raising awareness in the fight against climate change, the existing residential buildings have a significant energy savings potential. Therefore, increasing energy efficiency level in residential buildings should be recognized as an essential solution suggestion in reducing energy consumption. When taken into the account the ever-increasing energy demand and energy prices, this suggestion is essential for the national energy policy. Therefore, it is a primarily considered issue that the building sector, having the highest energy saving performance of all, produces buildings which have less energy consumption and CO2 emission, and lower energy costs. 
The improvement of residential buildings in terms of energy and cost efficiency is a complicated process, which differs from one building to the other and has many requirements. The proper methods considering energy, economic and environmental performances should be used for the proper analyses and the consistent results aimed at solving the complicated interactions in this process.  However, the energy, economic and environmental performances are usually assessed in the design or improvement of the existing buildings according to the fact that whether they meet the requirements defined in the current regulation or not; so the energy and cost efficiency and CO2 emission saving potentials are not analysed detailed.  
Besides, the studies related to the design and the improvement of the building are assessed in the form of different phases. The building performance significantly varies within the framework of the variants defined as data in the first phases. Therefore, it is important to control performance expectations regarding each phase within the building life cycle in order for the buildings to determine the energy saving potential. 
In this context, in terms of life cycle energy and cost efficiency, the methods should be developed for the building improvement under the light of the following objectives: 
•	Determining the energy saving, mitigation of CO2 emission and economic potentials in line with the measures taken during the life cycle,
•	Making analyses about the effects of these measures on life cycle, energy, economic and environmental performance and monitoring the changes according to different circumstances,
•	Assessing the energy and cost effective measures enabling optimum performance in accordance with the climate and in comparison with the current regulation, 
•	Suggesting optimum improvement combinations, which can be used by decision mechanisms for different climate zones.
Within the context of the thesis study, it is aimed that the effective measures on the improvement of building energy performance, which is important for optimum use in the sense of country resources and decision makers, are developed for different climate zones; and also the energy, economic and environmental performances of the residential buildings regarding these measures are assessed in the framework of life cycle. The approach developed in the framework of this purpose aims for the following definitions:
•	Defining the improvement measures enabling optimum performance in residential buildings in terms of life cycle energy consumption, CO2 emission and the costs,
•	Defining the optimum improvement combinations suitable for different climate zones.  
In this study based on life cycle energy, economic and environmental performance, the measures enabling energy saving and energy producing systems are examined with the aim of improving the energy performance of existing residential buildings. In the framework of energy saving measures, the building envelope development from among the passive building sub-systems, and the integration of photovoltaic (PV) systems to building envelope from among the energy producing systems are taken into consideration. In this context, it is aimed to determine the effect of each measure on life cycle energy consumption, CO2 emission and the costs. In order to evaluate the energy and environmental performance of the existing residential buildings, "Life Cycle Energy (LCE)" and "Life Cycle CO2 (LCCO2)" analyses developed based on LCA method are taken into consideration. For the evaluation of economic performance, "Life Cycle Cost (LCC)" analysis is used and "Discounted Payback Period" method as a supplementary method of LCC is additionally taken into account. In the framework of the LCC analysis, "Sensitivity Analysis" method is also considered to determine what extent to the variants developed regarding the defined measures effect the building economic performance. It could be examined the effect of the possible changes in data defined for each economic variant on the optimal solution in terms of life cycle energy and cost efficiency for the different climate zones by this method.
The alternatives with optimum performance are recognized as the ones with the minimum life cycle cost in the framework of the measures taken in terms of life cycle energy and cost efficiency. In line with this, the optimum improvement combinations, which are paired with the alternatives with optimum performance determined for different climate zones to increase the life cycle energy and cost efficiency of the existing residential building stock, can be identified. 
The effects of the measures, which are  considered in the framework of assessing life cycle energy, economic and environmental performances of optimum improvement combinations, can be determined by LCE, LCCO2 and LCC analyses repeated in terms of life cycle energy consumption, CO2 emission and cost. So, a comparison with the current performance level of the reference residential building could be made. As a result, the energy and cost efficiency levels of the optimum improvement combinations according to the current energy, economic and environmental performance of the reference residential building can be determined. 
According to this, the thesis study consists of six chapters. 
Chapter 1 explains the importance, extent and the aim of the thesis study and discusses the previous studies and methods carried out for this aim. 
Chapter 2 gives information about energy and cost efficiency in the buildings and identifies the effective variants in the determination of energy and cost efficiency. 
Chapter 3 explains Life Cycle Assessment (LCA), Life Cycle Energy (LCE), Life Cycle CO2 (LCCO2) and Life Cycle Cost (LCC)  analyses to be used for the evaluation of life cycle energy and economic performances. 
The approach to be used for the evaluation of optimum performances of the residential buildings for the different climate zones in terms of life cycle energy and cost efficiency is explained in the Chapter 4.  
The primary steps of the developed approach are as the following: 
•	Defining the reference residential building,
•	Defining the improvement measures,
•	The assessment of life cycle energy, economic and environmental performances of residential buildings,
•	In terms of life cycle energy and cost efficieny, determining the alternatives having an optimum performance for different climate zones and defining the optimum improvement combinations, 
•	Determining the life cycle energy and cost efficiency levels of the optimum improvement combinations according to the reference residential building.
Chapter 5 introduces the application study concerning the reference building for the different climate zones under the light of the approach developed. In this study, as a reference residential building, a mass housing project constructed by TOKI which has a significant role in dwelling production in Turkey has been chosen; this project involves common construction technologies and design criteria. One of the housing block in the mass housing project is defined as the reference residential building and is treated as if it is in different climate zones of Turkey. At the result of the applications, it is seen that the optimum performances of the residential buildings in terms of life cycle energy and cost efficiency for the different climate zones could be evaluated in consistent with the aim and the optimum improvement combinations could be identified. 
The results are summarized in Chapter 6. 
With this approach, it is possible to assess integrally the complicated effects of the measures, which are effective in the improvement of the building energy performance, on the energy, economic and environmental performances based on life cycle. Therefore, the results about optimizing the energy, economic and environmental performance related to the whole life cycle of the building could be used as data in the regulations. Thus, it provides the country resources and the decision makers with the right decisions at the maximum benefit. 
LCE, LCCO2 , and LCC analyses are carried out for the alternative group as part of the measures taken about the optimization of the building envelope with the aim of improving the existing residential building in consistent with the climate. At the result of the analyses, the variants enabling optimum peformance in terms of life cycle energy and cost efficiency could be determined for each climate zone.  This supports the next workings on both current and the next residential buildings from the point of technical information necessary for developing energy and cost efficiency. 
This approach provides the long-term strategy and policies concerning the residential buildings with overcoming the obstacles in dwelling production and changing the decision mechanism, which only considers the initial investment cost, based on life cycle approach. Thus, it is possible to assess the residential energy and environmental performance by a realistic approach. 
The approach determines the measures and variants enabling the minimum energy and cost effective requirements for each climate zone. So, the applications compatible with the current regulation and TOKI applications are evaluated from the point of life cycle energy and cost efficiency.  With the aim of increasing cost effective energy efficency of all housing stock, defining housing models which have the optimum performance in terms of life cycle energy and cost efficiency supports TOKI to product quality housing. Therefore, it makes possible the conscious supply-demand balance in residential sector. Also, the applicability of the approach in the existing residential buildings and in the design stage enables to make correct decisions during the design stage in terms of energy and cost efficiency. This kind of decisions both prevent the irremediable mistakes during the construction phase in the mass housing projects affecting a lot of people, and also makes it possible to establish sustainable residential environments by energy and cost effective residential buildings.