International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 05 Issue: 11 | Nov 2018 www.irjet.net p-ISSN: 2395-0072 © 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1154 A STUDY ON FACTORS AFFECTING ESTIMATION OF CONSTRUCTION PROJECT Dr. S Kanchana 1 , Ms. S Janani 2 1 Head of the Department, Department of Civil Engineering, RVS Technical Campus, Coimbatore-641402, India, 2 PG Student, Department of Civil Engineering, RVS Technical Campus, Coimbatore-641402, India ----------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Construction industry is considered as a very important sector for development in all over the world and the construction cost estimation is the most important element in it. Realistic estimation of construction cost is essential for both successful planning and completion of every construction project. The key factor for a successful project is the accurate cost estimation at its early stage. It is very difficult to quickly and accurately estimate construction costs at the planning stage itself when project information is limited. This study aim at caring out to identify the factors affecting construction cost estimation. The factors were identified based on questionnaire survey. Questionnaires were given to 64 experts in the construction industry aims to determine the importance of construction cost estimation and to determine the score of each factor. Statistical analysis will be carried out on the feedback of the respondents of the survey. RII value of the factors to be found using Microsoft Excel. The mean score of each factor to be determined and the p-value was calculated using the SPSS software. The significance of each factor used in the questionnaire to be determined. The important factors were identified using the mean score and their p-value. Key Words: Cost estimation, Questionnaire preparation, SPSS 1. INTRODUCTION Several factors affect the accuracy of building project’s cost estimation which must be considered at the early stage of the estimation process. Some factors can rapidly increase the estimated costs and the possibility of contractual strifes between the various parties involved. There are other factors that can help the estimator to decrease the unnecessary cost of an item and thus lead to successful tendering in a very competitive market. Therefore, for accurate estimating detailed study of the biding documents and the environmental situation are required. In order to arrive to the most accurate estimate of the probable cost consistent with the bidding time available and the accuracy and completeness of the information submitted, it also requires careful analysis of data of all projects. Realistic estimation of construction cost is essential for both successful planning and completion of all construction project. Also due to uncertain conditions, valid cost forecasts become an significant source of information for decision making by all construction parties. Accurate cost estimation at the early stage of a construction project is a significant factor in a successful project. But it is very difficult to quickly and accurately estimate construction costs at the planning stage, when drawings, documentation and the like are still incomplete. As such, numerous techniques have been applied to accurately estimate construction costs at an early stage, when project information is limited. While the numerous techniques have their pros and cons, thus there must be a little effort made to determine the best technique in terms of cost estimating performance. The purpose of this paper is to find the important factors affecting the cost estimation of construction projects. 1.1 OBJECTIVES  To explore the existing common practices in cost estimating.  To identify the significant factors affecting the construction cost. 2. LITERATURE REVIEW Aftab et.al., (2010) mentioned that the personnel of Project Management Consultant (PMC) ranked ineffective planning and scheduling by contractors as quite significant factor affecting construction cost. This issue seems to be true as it is highly related to cash flow and financial difficulties faced by contractors. Chimwaso K.D. (2001) mentioned that design changes, inadequate planning, unpredictable weather conditions and fluctuations in the cost of building materials are common factors causing cost overruns. Collier K (1987) emphasized the importance of the demand for construction works. He stated that: "It would be wrong to give the impression that all estimates and bids for construction work are made up of costs of labors, materials, equipment, job overhead costs, and operating overhead costs. All estimated from determined facts and calculated probabilities, and with a profit margin precisely computed according to current economic indicators". He added; "there are other things that at times may have a greater influence on the amount of a bid than any variations of those costs and the most important of these is the demand for construction work”. Harvey J (1979) has analyzed the "time" effect in relation to several of the other factors. Using dummy variables for "years", she found no significant interaction effects with the