Decision-making framework for positive energy building design through key performance indicators relating geometry, localization, energy and PV system integration

The effectiveness of positive energy building (PEB) design largely depends on a balanced approach between building design and energy performance. The current common architectural process is lacking guidelines to address the impact of early design decisions in achieving the energy positive building goals. A selection of case study office buildings with an intended architectural diversity provide homogenized real data for this research. The aim is to find connections among four fields that are relevant for the PEB design process: building geometry, location, energy consumption and building integrated photovoltaics. The interrelations among them are synthesized in several novel key performance indicators (KPIs) that conclude, i.a., that only buildings with a roof-to-façade area ratio higher than 28% may achieve a 100% self-sufficiency. The PV area corresponding to 15% of the envelope is a necessary starting threshold to achieve a self-sufficient PEB. The installed power capacity of the PV system should be above 30 Wp/m2c. The main contribution is a decision-making framework that can be sequentially applied providing useful limits, thresholds and figures that guide towards effective architectural decisions for PV system integration in the early PEB design process.