Potential of space zoning for energy efficiency through utilization efficiency

Energy efficiency improvements for buildings are required globally to reduce greenhouse gas emissions. Energy efficiency is typically calculated in relation to building size (kWh/m2a), which ignores utilization. A utilization perspective entails a paradox in terms of energy efficiency: When utilization increases, so does energy consumption, encouraging minimizing the use of buildings. This paper advocates the use of a utilization efficiency indicator to reveal the impact of building use on energy efficiency. As a concrete design strategy, this paper explores the energy efficiency impact of space zoning, in this context meaning grouping rooms with similar utilization to optimize building systems. To this end, multiple whole building simulations on different utilization variants have been conducted. The results show that such design can improve concrete energy efficiency through more efficient utilization. Simultaneously, the importance of proper space zoning and utilization is highlighted, as otherwise simply increasing usage can also have a negative energy efficiency impact. This study raised the need for systematic utilization design to be included throughout the design process.