Towards Zero Energy and Zero Emission Buildings—Definitions, Concepts, and Strategies

Abstract

This paper focuses on the definition and application of Zero Energy and Zero Emission Buildings (ZEBs). Based on a review of mainly European and Norwegian definitions, case studies, and pilot buildings, the paper summarizes some main challenges with respect to the implementation of ZEBs; What kind of strategies are used in current pilot projects of ZEBs? How to apply definitions and targets for ZEBs that take into account different available resources and boundary conditions? Previous studies have shown that most definitions of ZEBs include only the energy use for operation of buildings, while recent developments also include the embodied energy or emissions in materials. Published analyses of pilot building projects and case studies also show that most ZEBs apply a strategy of first reducing the energy need by applying efficiency measures, and then applying on-site or off-site renewable energy technologies. The findings indicate that prescribing a hierarchy of different ambition levels for the definition of ZEBs would be beneficial to allow for flexibility with respect to available resources and different boundary conditions.