Construction Cost-estimating software

The process described above for compiling construction cost estimates might be described as simple, routine, time consuming, even boring, but also essential, with requirements for accuracy, organisation, no omissions and no duplications. The spreadsheets used to prepare Tables 4.1 through 4.4 are examples of the use of information technology to manage effectively and efficiently the large amounts of cost-estimate data in a simple, logical manner and many contractors prepare their estimates using this well-suited application. Beyond the use of spreadsheets, several commercial software packages provide convenient ways of data management by combining spreadsheet concepts with the use of cost databases and other features. The basic structure of a cost-estimating program includes a spreadsheet-like table, with one line for each item, a means for calculating item quantities, databases of cost information, routines for determining and adding various add-ons, capability for all required cost calculations and means to interface with software that will be used to account for project costs as the project proceeds (Bennett, 2000). A sampling of available packages includes the Global Estimating® program developed and supported by BuildSoft Pty. Ltd (2002), the Precision Estimating Collection® (Timberline Software Corporation, 2002), which integrates the process from conceptual estimate to final bill of materials and also interfaces with its Gold Collection for project cost accounting and Everest®, an estimating and cost planning program available from Construction Software Services Partnership Pty. Ltd (2002). Several software developers, including BuildSoft, have taken the process a step further with on-line estimating systems, by which the user can upload schedules of quantities to a website, where subcontractors and material suppliers can attach their proposed prices electronically. Another package is the WinEst® 6.01 program (WinEstimator, Inc., 2002). We have utilised this package to produce an estimate for our concrete wall example, whose spreadsheet version was presented in Table 4.1. Details for each item are shown in Table 4.5, including take-off quantity and the unit cost for each element of cost, plus the several items of overhead and markup as discussed previously. Table 4.6 contains the same information in summary form; it is organised by major CSI section and includes the total, rather than the unit, cost for each major section.