Konut binalarında imalat girdileri, imalat ve imalat grupları bazında maliyet ve miktar analizleri

Abstract

Bu çalışmada konut binalarının yapımında kullanılan imalat girdi miktarlarının ve bu girdilerin maliyetlerinin birbirlerine göre ağırlıklarını tesbit etmek ve özellikle gereç tüketimlerine ilişkin bazı temel göstergeleri oluşturmak, ayrıca konut binaları bünyesinde yer alan imalat ve imalat grupları maliyetlerinin, inşaat işleri maliyetleri içerisindeki oranlarını saptayarak, konut yapımında inşaat işleri maliyetlerinde hangi imalat ve imalat gruplarının en büyük maliyet payına sahip olduğuna ilişkin bulgulara ulaşmak amaçlanmaktadır. Bu amaca ulaşmak için, Toplu Konut İdaresi tarafından Ankara-Eryaman'da yaptırılmış olan toplu konut projesi kapsamındaki 9 konut binası üzerinde, Doç. Dr. Murat Çıracı yürütücülüğünde yapılan "Eryaman (1. Etap) Konutları, Genel Tanıtım (Mimari Projeler, Bina özellikleri, Alansal Büyüklükler ve Göstergeler, Maliyetler)" adlı çalışma sonuçlan veri olarak kullanılarak analiz yapılmakta ve yukarıda tanımlanan amaca yönelik çeşitli bulgular elde edilmeye çalışılmaktadır. Konutlar üzerinde yapılan bu analizde miktar ve maliyet verisi olarak: Türkiye genelindeki inşaat sektörüne yönelik imalat ve imalat girdilerine ilişkin miktar ve maliyet bilgilerini içeren ve Bayındırlık ve İskan Bakanlığı tarafından, Bayındırlık ve İskan Bakanlığı Genel (İnşaat Birim) Fiyat Analizleri adı altında her yıl yayımlanan analizler kullanılarak miktar verilerine ulaşılmakta ve maliyet verileri günceleştirilmektedir. Çalışmanın 2. bölümünde Bayındırlık ve İskan Bakanlığı Genel (İnşaat Birim) Fiyat Analizleri tanıtılarak, analizde sıkça geçen kavramların tanımları yapılmaktadır. 3. bölümde ise Doç. Dr. Murat Çıracı tarafından yürütülen "Eryaman (1. Etap) Konutları, Genel Tanıtım (Mimari Projeler, Bina Özellikleri, Alansal Büyüklükler ve Göstergeler, Maliyetler)" adlı çalışma sonuçlarının üzerinde analiz yapılan toplu konut binaları genel özellikleri ile tanıtılarak, çalışmada amaçlanan bulgulara ulaşmak için söz konusu binalar üzerinde yapılan analizde izlenen yöntem tanıtılmakta ve yine bu bölümde her bir bina için gerçekleştirilen analiz adımları açıklanmaktadır. Çalışmanın 4. bölümünde ise 3. bölümde miktar ve maliyet yönünden incelenen konutlar için elde edilen bulgular:. İmalat Girdileri Bazında Maliyet ve Miktar Analizleri. İmalat ve İmalat Grupları Bazında Maliyet Analizleri olmak üzere iki grupta sınıflandırılarak tüm binalar için ortalama değerler oluşturacaktadır. Sonuç bölümünde ise 4. bölümde ulaşılan bulgular özetlenerek, bu bulguların hangi doğrultuda kullanılabileceği ve yararlılığı tartışılmaktadır.

Cost saving is one of the fundamental problems concerning buildings in general and residential buildings in particular. Various research has been conducted at different levels With the purpose to find ways of cost savings especially for residential buildings. The past researches are mostly about factors influencing the costs of design, project delivery systems, alternative types of organizing residence construction that might be relevant for acquiring residences, financing residences, technologies of residence construction and other similar subjects. Within the literature and past research studied, however, information could not be found on the consumption of manufacturing inputs used, their quantity, kind, number and the ratio of the costs of inputs. In other words, there are no data regarding the quantity and the percentage of the costs of different kinds of inputs such as labour, construction machinery and equipment and material. There is no accurate knowledge on the kinds of inputs used and the ratio of these inputs, especially for residential buildings. In relation to this, question such as the position of these inputs acquired mostly form natural resources within the national economy, the potential production possibilities, the necessary quantity of the fundamental inputs needed for satisfying the need for residences and the way the investment programs should be developed to meet these ends, are left unanswered. This thesis might be considered as an introductory research study to find solutions to the above stated problems. For this reason, the study is aimed to determine the ratio of the quantities of the inputs as well as the ratio of the costs of these inputs used for constructing residential buildings and to develop certain fundamental indexes regarding the consumption of materials. Besides, by means of calculating the ratio of the costs of manufacturing and manufacturing groups within the costs of construction, the study aims to reach results regarding which manufacturing and manufacturing groups have the highest percentage among the costs of construction. To meet these ends, the study obtains various results related to the above defined objectives by means of analysing nine residential buildings within the scope of the house project carried out in Ankara-Eryaman by Project House Directory. In order to reach the above stated purpose, the data or resource opportunities necessary for correctly determining the quantity of inputs used for the construction of residential buildings and necessary for determining the ratio of the costs of manufacturing and manufacturing groups, are very limited. The only document and official report that exists in Turkey on this subject is the analysis named "Ministry of Settling and Public Works General (Unit of Construction) Price Analysis" (BFA) published annually by the Ministry of Settling and Public Works. These texts include quantity and cost information regarding manufacturing and manufacturing inputs. In this analysis, quantity data are obtained and cost data are updated by means of using the "1997 Ministry of Settling and Public Works General (Unit of Construction) Price Analysis" as the data on quantity and cost. In the second part of this study, the concepts, that are very often used, are defined by means of introducing the "Ministry of Settling and Public Works General (Unit of Construction) Price Analysis". Furthermore, unit price lists, unit price analysis and the current value lists used in the analysis that are used in the third part, are explained. In the third part, the structure of the results of the study named "Eryaman (1st Set) Residences, General Introduction (Architectural Projects, Characteristics of Buildings, Sizes of Areas, Indexes and Costs)", and that is carried out by Assoc. Prof. Murat Çıracı, will be explained. In this way, nine different residential building that are within the body of Eryaman (1st Set) residences, will be introduced. The common characteristic of the residences is that they are all constructed by the tunnel mould technology. The most obvious characteristic that differentiates these residences is the differences in the numbers of flats and the numbers of apartments in each flat. In the second part of this section, the steps of analysis will be indicated by means of explaining the method of analysis applied on Eryaman (1st Set) Residences. The analysis* that consist of quantity and cost analysis, have been carried out in twelve steps. Some of these analysis steps are carried out separately for each building and the findings obtained from these analyses are used as data for all the buildings in the fourth part. The steps carried out in the analysis are as followed:. STEP 1: Classifying the manufactures within the body of Eryaman (1st set) residences according to BFA classifications and identifying the special manufactures that do not take place in BFA.. STEP 2: Quantity Analysis on the Basis of Manufacturing Inputs. Identifying the manufacturing input according to BFA; finding out the total quantity of manufacturing input by means of calculating the quantity of manufacturing input for each building.. STEP 2.1: Determining the total quantity of labour for each building.. STEP 2.2: Determining the total quantity of construction machinery and equipment for each building.. STEP 2.3: Determining the total quantity of material for each building.. STEP 3: Finding out the average quantity of material used in each m2 of the construction area of all the buildings.. STEP 3.1: Determining the average amount of labour force used in each m2 of the construction area of all the buildings. . STEP 3.2: Determining the average amount of construction machinery and equipment used in each m2 of the construction area of all the buildings. » STEP 3.3: Determining the average amount of material used in each m2 of the construction area of all the buildings.. STEP 4: Analysis of Cost on the Basis of Manufacturing Inputs. Calculation of the costs of manufacturing inputs for each building according to BFA current value in 1997.. STEP 4.1 : Calculating the cost of labour for each building.. STEP 4.2: Calculating the cost of construction machinery and equipment for each building.. STEP 4.3: Calculating the cost of material for each building.. STEP 5: Calculating the costs of average input sub-groups per each m2 of construction area of all buildings.. STEP 5.1: Calculating the average cost of labour groups per each m2 of construction area of all buildings.. STEP 5.2: Calculating the average cost of construction machinery and equipment groups per each m2 of construction area of all buildings.. STEP 5.3: Calculating the average cost of material groups per each m of construction area of all buildings.. STEP 6: Calculating the cost of different kinds of average cost per each m of construction area of all buildings.. STEP 7: Analysis of Cost on the Basis of Manufacturing and Manufacturing Groups. Calculating the cost of manufacturing and manufacturing groups per each m2 of construction area of all buildings according to the 1997 BFA current value.. STEP 8: Calculating the average cost of manufacturing and manufacturing groups per each m2 of construction area of all buildings.. STEP 9: Listing the average manufacturing cost of each building per each m2 of construction area according to their percentage in the total cost.. STEP 10: Listing the average cost of manufacturing inputs of each building per each m2 of construction area according to their percentage in the total cost.. STEP 11: Finding out the percentage of cost types among the cost of manufacturing and manufacturing groups per each m2 of construction area of each building.. STEP 12: Finding out the average percentage of cost types among the cost of manufacturing and manufacturing groups per each m2 of construction area of all buildings. XIV . STEP 12.1 : Finding out the average percentage of the cost of labour among the costs of manufacturing and manufacturing groups per each m2 of construction area of all buildings.. STEP 12.2: Finding out the average percentage of the cost of construction machinery and equipment among the costs of manufacturing and manufacturing groups per each m2 of construction area of all buildings.. STEP 12.3: Finding out the average percentage of the cost of material among the costs of manufacturing and manufacturing groups per each m2 of construction area of all buildings. In the fourth part of the study, the findings obtained in the third part for the residences analysed in terms of quantity and cost are classified in two groups. Analysis of Cost and Quantity on the Basis of Manufacturing Inputs. Analysis of Cost on the Basis of Manufacturing and Manufacturing Groups. The two groups are demonstrated in Figure 1. In this way, average values are found out for all the buildings through the steps demonstrated in the figure. In the conclusion part, the findings reached in the fourth part are summarised; for what ends these findings can be used and their utility are discussed. The findings obtained as a result of this study can be summarised as follows: Findings of Analysis on the Basis of Manufacturing Inputs:. It is found out that the cost of material has the highest percentage with 66 % among the cost variables (labouring, construction machinery and equipment and material). It is also the manufacturing input that has the greatest influence on the costs of residential buildings.. It is found out that the Essential Construction Material group (pebble, sand, cement, facade bricks, wall bricks, tiles, etc.) has the greatest percentage with 18 % among the costs of material groups.. It is found out that the cost of labour has the greatest percentage with 31 % among the cost variables (labour, construction machinery and equipments and material). It is found out that construction machinery and equipments have a small percentage with 3 % among the different cost variables. Therefore, it does not as much influence the cost of residential buildings compared to other cost variables. XV 1 »0 " J»." «8° BU W i H^ T bO Ö i.8 3 & >S bO a 'C İ o en 'ot PQ g OT 60 C 3 c u 12 'ot od o a) 3 a OT O U E OT S" O XVI Findings of Analysis on the Basis of Manufacturing and Manufacturing Groups:. Within the costs of construction works, the manufactures that have the greatest percentage of cost among the 134 manufactures are as following: 1 6.043 Iron B225 Concrete 1 1.52 % ÖİML-9 Tunnel Mould 8.13% 30. 101 Pre-made Facade Board 5.80 %. Within the cost of construction works, the manufacturing groups that have the highest cost percentage among the 18 manufacturing groups are as follows: ÖÎML Special Manufactures 15.5% 27 Plaster-Seam- Alum Works 15.4% 23 Ironworks 13.7%. The manufacturing groups that have the highest cost of labour among the manufacturing groups and the ratio of labour costs per each m2 construction are as follows: 27 Plaster-Seam-Alum Works 7.3% ÖÎML Special Manufactures 6.4 % 23 Ironworks 3.0%. The manufacturing groups that have the highest cost of construction machinery and equipment among the manufacturing groups and the ratio of the costs of construction machinery and equipment per each m2 of construction area are as follows: ÖÎML Special Manufactures 2.64 % 15 Excavations with Machinery 0.15%. The manufacturing groups that have the highest cost of material among the manufacturing groups and the ratio of the costs of material per each m2 of construction area are as follows: As it is also obvious from the summary of the findings obtained as a result of the analysis conducted in the above research, one of the most striking results of the research is mat among the costs of all the construction works of residences, the percentage of material costs with 66 % is very high in comparison with the other manufacturing inputs. As opposed to this, the cost of construction machinery and equipments is very low with 3 % as opposed to what is expected. In this way, it is seen that the highest potential for cost saving of building residences lies in the materials. According to our point of view, besides all the other precautions that will help to economise on the costs of building residences, the decrease of the consumptions of materials is an important goal. Since we have come across no other similar researches, the findings of this research are not evaluated on a comparative basis. On the other hand, the residences subject to this research have been built by the tunnel mould technology. If similar inputs analysis are made for residences constructed with different technologies in the researches to be conducted hereafter, the quantities of inputs for residences constructed with different technologies could be compared. The analyses in this study are structured as indexes of values per m2 construction area. These indexes enable to develop hypothesis regarding the current capacity of material production as well as the necessary quantity of production that is dependent on the need for residential buildings. These hypotheses could be at a national scale as well as for a single project. Another utility that is provided by the indexes indicating the quanties of inputs necessary per m2 of the construction area is that the cost calculation of the design of buildings with similar characteristics is made possible. In this cost prediction, the quantities of inputs used per each m2 of the construction area will enable us to calculate the current value at the time the cost calculation was made. It will further enable us to calculate the cost of the designed building by means of multiplying the current value by the total are of construction. However, in order to use these indexes as tools of prediction in the pre-design phase, they have to be tested and developed with other researches.