Yüklenici Firmalar İçin Sürdürülebilir Yapım Kılavuzu Oluşturulması Ve Leed Uygulamalarında Karşılaşılan Zorlukların İncelenmesi

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Tarih
2014-07-04
Yazarlar
Yılmaz, Dinçer İnanç
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Yayınevi
Fen Bilimleri Enstitüsü
Institute of Science and Technology
Özet
Küresel ısınma tehtidi ve doğal kaynaklarımızın aslında sınırsız olmadığı bilincinin yaygınlaşmasıyla birlikte sürdürülebilirlik kavramı ortaya çıkmış ve pek çok farklı disiplinde son yarım yüzyıldır akademik çalışmaların önemli odaklarından biri haline gelmiştir. Sürdürülebilirlik gelişmiş ve gelişmekte olan tüm toplumları etkilediğinden pek çok ülke bu konu ile yakından ilgilenmekte ve sürdürülebilirliği konu alan bilimsel çalışmalara destek olmaktadır. Ülkemizde de pek çok disiplinde ve disiplinler arası konularda sürdürülebilir çözümleri hedef alan çalışmalar desteklenmekte ve özendirilmektedir. Öte yandan sürdürülebilirlik konusuna hassasiyetin artması neredeyse tüm sektörleri etkilemiştir. Bu etkileşimler sektörden sektöre farklılıklar göstermekle beraber,  gelişim odaklı ve uygulama alanı en yaygın sektörlerden biri olan inşaat sektörü de sürdürülebilirlik olgusundan büyük ölçüde etkilenmiştir. İnşaat sektöründe sürdürülebilir yapım yaklaşımı yeşil bina kavramını doğurmuş,  bu kavram tüm dünyaya kısa sürede yayılmış ve uygulama alanı bulmuştur. Yeşil binalar, çevreye duyarlılığı yüksek ve doğaya saygılı yapılar olarak tanımlanmaktadır ve günümüzde başta Birleşik Devletlerdeki USGBC'nin LEED sertifikası olmak üzere pek çok yeşil bina sertifikasyon sistemiyle belgelenmekte böylece yapının sürdürülebilirliğe katkısı derecelendirilmektedir. Yeşil bina sertifika sistemleri, yapıyı tüm yaşam döngüsü üzerinden değerlendirmektedir. Tasarım, yapım, kullanım ve yıkım aşamaları dahil olmak üzere bir yapı yaşam döngüsünün tüm aşamalarında doğayla ve insanlarla doğrudan etkileşim halinde bulunmaktadır. Sürdürülebilir mimarlık ve mühendislik prensipleri ile tasarımın yanı sıra yapının yaşam döngüsündeki tüm aşamalarını etkileyen yapım sürecini sahasında yani, şantiyesinde yöneten ise ana yükleniciden başkası değildir. Bu bağlamda sürdürülebilir yapım konusunda yüklenicilerin son derece önemli görev ve sorumlulukları bulunmaktadır. Ancak yapılan çalışmalar, yüklenici firmalarda bu konudaki bilinç seviyesinin olması gerekenden oldukça düşük bir seviyede olduğunu göstermektedir.  Bu çalışma kapsamında inşaat sektörünün başlıca aktörlerinden olan yüklenici firmaların sürdürülebilir yapım ve yeşil bina projelerindeki rolü, görevleri, sorumlulukları, karşılaştıkları zorluklar ve zorlukları aşma stratejileri incelenmiştir.  Çalışmada öncelikle sürdürülebilir yapımda yüklenicilerin rolü üzerine detaylı bir literatür çalışması yapılmış ve dünyada en çok kullanılan yeşil bina sertifikasyon sistemi olan LEED sertifikası esas alınarak yeşil bina projeleri kapsamında yüklenicilerin görevleri detaylı olarak belirlenmiştir. Yüklenicilerin belirlenen görev ve sorumlulukları inşaat projelerinin evreleri ile eşleştirilerek süreç bazlı modellenmiş ve böylece yüklenicilere yönelik bir sürdürülebilir yapım kılavuzu oluşturulmuştur. Bu görevlerin Türk inşaat sektörü bağlamında uygulanmasının ne derece zor olabileceğinin belirlenmesi, mevcut projelerde karşılaşılan zorlukların anlaşılması ve bu zorlukların aşılmasında öneriler geliştirilebilmesi için tez çalışması kapsamında geniş çaplı bir alan çalışması yapılmıştır. Alan çalışmasında Türkiye'de 2014 Ocak itibariyle LEED sertifikası almış olan tüm projelerin ana yüklenici firmaları tespit edilmiş ve bu yüklenicilerin LEED sertifikası alan projelerinin yöneticileri ile yüz yüze anket çalışması gerçekleştirilmiştir. Literatür analizi sonucunda belirlenen yüklenici odaklı LEED kredileri ve yüklenici görevlerinin Türk inşaat sektöründe uygulanabilirliği firmalar tarafından puanlandırılmış, bu puanlar projelerin gerçekleşen başarı durumlarını gösteren puan kartlarındaki verilerle de karşılaştırılarak değerlendirilmiştir. Yapılan analizlerde firma özellikleri ve firmalarda bulunan çeşitli sürdürülebilir yapım uygulamaları ile ilgili de bilgi toplanmış ve bunların firmaların LEED uygulama kapasitesi ile etkileşimi, LEED sürecinin firmanın iş yapma şekline etkileri ve firmaların LEED kredileri ile ilgili algısı ile gerçekten alınabilen puanların ilişkisi gibi konularda önemli bulgular elde edilmiştir. Öte yandan, ülkemizde çok yeni olan bu sertifika sisteminin, dünyadaki yüklenici firmaları nerede ve ne ölçüde zorladığını araştırmış olan yabancı akademik çalışmalardan faydalanarak, yüklenici firmaların karşılaştıkları zorluklar belirlenmiş ve bu zorlukların Türk inşaat sektörü bağlamındaki önem dereceleri ve bu zorlukları aşmada kullandıkları stratejiler yine anket kapsamında ana yüklenicilerden elde edilmiştir.  Sonuçta, ülkemizdeki ana yüklenici firmaları gerçekleştirecekleri başta LEED olmak üzere yeşil bina projelerinde üstlenecekleri görevler, süreç temelli sorumluluklar, karşılaşabilecekleri zorluklar ve bu zorlukları aşmada kullanabilecekleri stratejiler konularında bilgilendirecek olan bu çalışma bir bilgi kılavuzu olması amacıyla hazırlanmıştır.
The term sustainability emerged along with the increasing global warming threat and the consciousness regarding possible natural resource scarcity, and it has become a focus point for academic works related to various disciplines over the last half-century. Since it relevantly affects countries either developed or developing, sustainability is a state-aided topic for scientific research. Works regarding many disciplines and topics related to multidisciplinary branches are supported and encouraged in our country with proportion to their aim to achieve sustainable results. On the other hand, almost all sectors are affected by the increasing sensitivity to the sustainability topic. Along with the fact that these affections may vary for different sectors, construction sector which is both innovative and widespread is affected throughly by sustainability subject. As the term sustainability is becoming extensive knowledge, the traditional construction methods in the world construction sector are gradually replaced by methods that are environment sensitive, produce less waste and consume less resources, adaptable to advanced sustainable technology usage. The projects which are subject to sustainable design and construction are defined `Green Buildings` among the construction sector and this term has emerged from the sustainability approach in the sector. This concept has expanded all over the world in short time. Green structures are defined as buildings with higher environment sensitivity and deeper respect to nature and such projects are evaluated by various global certification mechanisms namely LEED, BREEAM and DGNB. At the present day, many green buildings are documented by certification systems such as the LEED  certificate of USGBC in USA, thus grading the buildings contribution to sustainability. Similarly, the awareness in Turkey over the concepts of sustainable design, sustainable construction and green buildings is escalating. By 2014 February, there are 48 projects with LEED certificate and over 300 candidates to certification. Green building certification mechanisms rate buildings on their entire lifetime performances. A building is directly in exchange with nature and people over their entire lifetime including periods of design, construction, service and destruction. The responsibilty of the `on site` construction period, which is one of the most important process that affects all periods of a buildings entire  life span belongs to no one other than the contractor, along with their responsibility over sustainable architecture and engineering. In this regard, contractors generally have key duties and responsibilities concerning sustainable construction. Green buildings which require active involvement and cooperation of all relevant shareholders, demands insight, management, usage of methods and tools appropriate to sustainability fundamentals. The experiences and know-how of the contractors are of high importance at this phase. On the other hand, researches uncovered that contractors are among the shareholders  who have the least knowledge over this subject. The question to be asked at this point is whether contractor companies are ready for sustainable construction or not. Bearing in mind that it has only been five years since the preliminary certificated green building projects emerged in Turkey,  it is far too optimistic to expect this concept to be firmly pursued by contractors given the current circumstances of the sector. Contractors mainly stay out of the base decisions made by participation of the employer, designers and green building advisors, and this situation has serious negative effects on project success. Meanwhile contractors have crucial problems in management and planning due to the lack of knowledge, they also have hard time finding expert employees and environment-friendly materials. Considering these problems, the research studies the roles, duties, responsibilities, difficulties encountered and the strategies to overcome difficulties of contractor firms who are one of the main actors in construction sector and to develop a sustainable construction guide is aimed. Primarily, a detailed literature review is conducted over the role of contractors in sustainable construction and by picking the most popular green building certification system LEED as example; task allocation is conducted in the LEED process with determining which credit is within responsibility of which shareholder among all credits. The LEED credits that concern the contractor have been determined among other credits that are of architectural, statical, electrical, mechanical, landscaping concerns and also those which concern the employer.  Furthermore, the main credits that include the credits concerning contractors in LEED certificate system, namely sustainable sites, water efficiency, energy & atmosphere, material & resources, indoor environmental quality and innovation are studied with detail. With the literature review of LEED credits that contractors are responsible of and using that knowledge in synthesis with the studied LEED reference book, the duties of contractors in LEED certificate system have been determined. In the following stage, which credits that involve contractors are of which stages of the construction project are determined beneath three different phases, which are pre-construction, construction and after-construction phases. These credits which have been seperated to construction phases they belong, have been merged with the contractor duties previously identified and a contractor duties and responsibilities table has been generated. The duties and responsibilities of contractors are modelled by taking phases as basis such that the stages of construction, namely: feasibility, design, contract, mobilisation, construction, service and maintainance-repair are paired with correspondent duties and responsibilities. Thus, a sustainable construction guide for contractors has been formed. A wide ranged field study has been conducted in the thesis, in order to determine how hard applying these duties in Turkish construction sector can be, to understand the difficulties encountered in current projects and to develop recommendations to overcome identified difficulties. The practicability ranks of each duty concerning contractors and the importance ranks of difficulties encountered by contractors have been added to the guide model. The field study has been conducted with contractor companies in Turkey which have obtained LEED certificates. Main contractors of 48 projects in Turkey which have LEED certificate by this February are determined and one-on-one survey research has been made with the relevant contractor managers of the projects that have LEED certificate. The contractor companies have graded the previously determined contractor relevant LEED credits and practicability of contractor tasks in Turkish construction sector, the points obtained from their grading have been evaluated with comparison to data in point cards which show the projects current success rate. With the help of data obtained from field study, company properties of contractors which have projects with LEED certificates are identified. These company properties can be listed as: sectoral experience of the company, total revenue of the company in 2013, fields of activity of the company, the roles of the company in the projeccts, the number of active employees the company employ, the presence of ISO14001 in the company, the number of green building experts in the company, the actuality of environmental management plan in the company, the actuality of waste management plan in the company, the awareness in the company regarding national certificates, the green certificate choices of the company, LEED knowledge of the company, to what degree the business ways of the company are affected by LEED projects, how helpful the companies would expect the LEED guide to be, which organizations the company is member of. The types of certificated projects in Turkey are: LEED O+M: EB (v2009), LEED ID+C: CI (v2.0), LEED ID+C: CI (v2009), LEED BD+C: CS (v2009), LEED BD+C: NC (v2.2), LEED BD+C: NC (v2009), LEED BD+C: CS (v2.0), LEED BD+C: R (v2009), LEED ID+C: R (v2009).   After all these certificates are interpolated to LEED v2009 level, the real success status of contractor based credits have become comparible. Thereby, real and comparible success points are obtained using survey data (The occasion that companies rate themselves).  During the analysis conducted, information about company properties and various sustainable construction applications that exist in the company are gathered and important discoveries are made connected to the interaction between the information gathered and the companies LEED application capacity, the effects of LEED process to the methods of business of the company and the interaction between companies perception of LEED credits and the points achieved in reality. Within the context of these analyses, three hypotheses determined at the beginning of the research have been tested. These hypotheses are: (H1) There are correlations between the contractor firm properties and the LEED application capacity (LUK) of the company, (H2) There are correlations between LUK and realized LEED success points (LBP) of the contractors and (H3) There is a correlation between applicability points (UP) determined by contractors regarding LEED criteria and realized mean points (OP). With respect to results gathered and analyses conducted, H1 is accepted, H2 and H3 are rejected. On the other hand, using the foreign academical articles about the contractors having hard time adapting their traditional ways to a new certification system all over the world, the difficulties contractors encounter have been determined and are compared to those of Turkish construction sector in their ranks of importance and the strategies used in the Turkey to overcome these difficulties have been gathered from contractors using survey method. As a result, this research is conducted to help as a informative guide for contractor companies in current and future green building projects they may encounter difficulties in (possibly LEED related) concerning the duties, phase based responsibilities and strategies they can use  to overcome difficulties. A contractor company in a project that aims LEED certificate should use this model developed, to get help in the areas: (1) Learning about and focusing on the credits in the LEED system regarding the duty distribution of the shareholders and learning about and focusing on which credits these are; (2) Determining the duties and responsibilities in order to achieve credits that are contractor related in LEED; (3) Being able to see in which phases among feasibility, design, contract, mobilisation, construction, service and maintainance-repair it is necessary to realize the contractor focused credits and duties within radius of LEED, Being able to integrate LEED related  tasks to the programme; being timely on preparations such as resource, workforce, documentation, market research and material supply; (4) Getting knowledge over credits and duties they can get easily and over those they can have difficulty in, using the color coding in which they can find the applicability rank for every duty and credit. As a result, it is hoped that this study would help in the way of contractors in our country getting higher success rate regarding LEED certificates and building applications that respect nature.
Açıklama
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2014
Thesis (M.Sc.) -- İstanbul Technical University, Instıtute of Science and Technology, 2014
Anahtar kelimeler
Leed, Sürdürülebilir Yapım, Yüklenici, Yeşil Bina, Çevresel Sürdürülebilirlik, Leed, Sustainable Construction, Contractor, Green, Environmental Sustainability
Alıntı