Making investment decisions during a property’s planning process in terms of life-cycle costing means to consider both the immediate, initial costs (construction costs) and the long-term, follow-up costs (occupancy costs) - summarily a building’s life-cycle costs. Therefore, the calculation model has to be clearly defined and to follow an appropriate data structure. Besides, the processes during the life cycle have to be priced to enable the investment calculation. This approach is ideally executed with specific and realistic values for the building. However, today’s life-cycle costing, especially for laboratory buildings, is characterized by a high degree of standardization, uniform calculation parameters and "fixed" specific values i.e. for the purpose of benchmarking in the context of sustainability certifications.

The aim of this study is to identify and operationalize specific cost-influential factors on operating costs of laboratory buildings in order to develop specific life-cycle costing through reference to a practical tool for planning costs. Likewise, this tool could even allow benchmarking within sustainability certifications. In this context, cost-influential factors won from literature and existing data pools are integrated in an interview guide to conduct qualitative expert interviews. These serve to filter the essential cost-influential factors on laboratory buildings’ operating costs. Therefore, the cost drivers are structured after six categories: strategy, use, construction and technological characteristics, location, and miscellaneous. In the interview, the expert assesses and explains the cost-influential factors regarding their impact on the different cost groups like supply, disposal, cleaning, inspection, levies and contributions, and security services. The weighting and shaping of the cost-influential factors will help afterwards to specify the operating costs for each cost group in life-cycle costing of laboratory buildings.

The object of investigation is narrowed to laboratory buildings with an exhaust air volume flow of 12,5 – 25 [m³/(m² UFA)] per hour which corresponds to an 4-8-way air exchange. (UFA - Usable Floor Area