"Roter Faden" für die Qualitätssicherung: Nachhaltige Gebäudeoptimierung durch Lebenszyluskostenplanung

The current research project "life-cycle-oriented quality improvement of buildings (in short: LQG)", which is funded by the FFG and in which five Austrian applied universities and six industry partners are involved, deals with the environmental, economic and qualitative improvement of buildings over their entire life cycle. The present paper focuses on an extension of the energy certificate by an economic and ecological assessment. Based on an example it is shown how a future building can be optimized according to LCC and LCA criteria. The effects of changing various building parts or HVAC components are shown. The economic evaluation is based on a life cycle cost calculation and the ecological results are based on a LCA calculation. For the calculation of the required energy demand, which is also the basis for the other calculations, an available Excel calculation tool for the Energy Performance Certificate is used. The calculations of the energy certificate are incorporated into both the economic and the ecological expansion of Excel tool. The life cycle cost (LCC) are calculated from the investment costs and the discounted projected usage costs over its expected life. The forecast is based on the one hand on benchmarks for the entire building on the other hand on more detailed calculations for the building component facade or for the HVAC component ventilation system. The calculation of key ratios for the LCA is based on the mass determination of the components extracted from databases and the material data. These are combined with the energy consumption data, the emission ratios of the energy carriers and lifetimes of the individual components into an overall Life Cycle Assessment (LCA). Again, a balance sheet for the whole building is calculated, but the data collected for compared components are much more detailed.