Towards net zero energy buildings: Dynamic simulations of an office building in three climate zones of Europe

With the increasing trend toward energy efficient and nearly or net zero energy buildings, there is a need for a holistic approach to optimize building energy performance parameters. The objective of this paper is to define the heating, cooling, and electricity demand of a commercial office building in three different climate regions: Northern Europe - Finland, Central Europe-United Kingdom, and Southern Europe - Romania. Dynamic simulations were performed using the building performance simulation programme IDA Indoor Climate and Energy (IDA ICE) for three energy efficiency levels. To define the optimal solution for each climate zone, three cases for each were defined: (a) Business as usual case as a base case where the input values are taken directly from the existing country regulations; (b) Energy efficient case; and (c) Zero energy case, where the input values are obtained by expert knowledge supported with approximately 50 optimised rounds of dynamic simulations. Thus, the primary focus of this research is to reduce an office building's annual energy consumption demand through effective utilization of energy efficient system solutions and concepts. Future research efforts will use the results obtained in this study to set system level parameters, coupled with renewable energy sources for on-site energy production, to achieve energy balance over an annual cycle.