Integrated conceptual cost estimating and life cycle costing system for building projects

Cost estimates are considered the most important and critical mission during the life cycle of a construction project. Preparing reliable and accurate estimates to help decision makers is the most challenging assignment that cost engineers and estimators can face. For decades, the construction industry focused on acquiring the construction costs of building facilities, neglecting the associated costs of running and maintaining them. Currently, by contrast, owners are interested in investigating the economics of facility management, which are the cost of owning and operating the building over its useful life.

This thesis presents a methodology that can be used for an integrated conceptual cost estimating and life-cycle costing system for building projects. The methodology describes the development and implementation of a system that automates the preparation of conceptual cost estimates and forecasts future costs of running building projects. This methodology does so by joining Computer Integrated Construction (CIC) and Virtual Reality Environment (VRE). The system integrates relational databases, a preliminary estimate module, an AutoCAD module, a global module, a cost estimate forecasting and decision support-system modules, and life-cycle costing and sensitivity analysis modules.

A modification in building design will result in an automatic generation of a new conceptual estimate. Subsequently, this modified drawing can be virtually animated and visualized by using a Virtual Reality browser. Finally, once capital costs are identified, the system forecasts the cost of running and maintaining the new building during its expected service life. Then, after assigning the range of deviation, it applies a sensitivity analysis method to investigate the most sensitive parameters so that further attention can be directed.

Designing the system in a user-friendly environment allows owners and decision makers to envision the feasibility of new building projects within their anticipated life cycle. Moreover, it assists architects and cost engineers to generate conceptual cost estimates in a dynamic environment. A numerical example is presented to illustrate the usefulness and capabilities of the developed system.