A Visual Approach to Construction Cost Estimating

A VISUAL APPROACH TO CONSTRUCTION COST ESTIMATING Phuwadol Samphaongoen, B.S. Marquette University, 2010 Construction cost estimating is considered one of the most important and critical phases of a construction project. Preparing reliable and accurate estimates to help decision makers is the most challenging assignment that estimators face. An estimate is not only necessary for proposal preparation but also for several project management functions. Despite the importance of estimating, it has remained a very time consuming process. The most inefficient part of construction cost estimating is determination of the amount of resources needed for the construction of a project. This is also known as quantity takeoff. Quantity takeoff is a very long and error-prone process that is performed manually by estimators. Missing or duplicating work items are among the errors that can occur during the quantity takeoff process. New Parametric CAD software has recently attained widespread attention in the Architectural, Engineering, and Construction (AEC) industry. It represents the development and use of computer-generated models to simulate the planning, design, construction and operation of a facility. It helps architects, engineers, and contractors visualize what is to be built in a simulated environment and to identify potential design, construction or operational problems. The model created from parametric CAD software will significantly increase construction cost estimator productivity by substantially reducing the manual work necessary for performing quantity takeoffs. This study presents a methodology that uses parametric CAD software and visualization technologies to streamline the estimating process. Although this methodology won’t totally automate the estimating process, it will help in the following areas: (1) providing a navigable 3D model of the project, (2) simplifying the quantity takeoff process, and (3) eliminating manual calculations and search for data. This study uses visualization technologies to navigate through a 3D CAD model. This would provide the estimator with a tool to improve the understanding of the location and relationships between elements in a model. The quantity takeoff process may be simplified by using properties and geometry information extracted from the 3D CAD model. This study also uses a database technology to store labor, equipment, and material cost data. This helps eliminate manual calculations and enables an estimator to search for data stored in the database. A case study is presented to illustrate the process and capabilities of the developed system.