Building life cycle optimization tools for early design phases

•The early planning phases are crucial for the life cycle building performance.•The LCC-tools-test displays a convergence in the construction costs of 7%.•The convergence of the following costs using the same tools is even 38%.•With the increasing energy-efficiency level, the construction costs are increasing.•Need for optimization of the energy-savings and life-cycle costs and benefits.

The early building design phases play crucial role for the determination of building's life cycle performance in terms of resources and energy consumption and development of LCC (life cycle costs). In this stage the optimization potential is still very large, at very low cost. In the latter planning phases the change possibility rapidly decreases with simultaneously increasing costs. The investors and planners are increasingly requiring design tools as decision support instruments, which would enable simulation and optimization of LCC already in the early planning phases. This paper will present a comparative study of three commercial software-tools for LCC-calculation, and test their fitness for the implementation in the early design phases. Using a Case Study of an energy efficient building, LCC were assessed employing the three tools and the deviations of the results were compared. The analysis showed, that the tested tools cannot be employed in the early design phases without adoption and customization, lacking of benchmarks and extensive data representing the largest problem for a reliable LCC calculation and optimization. In further step, a strategy for investors for the assessment of LCC in the architectural competitions as decision support was developed and verified on a real-life project.