Globally, there are significant challenges to meeting built environment performance targets. The gaps found between the predicted performance of new or retrofit buildings and their actual performance impede an understanding of how to achieve these targets. This paper points to the importance of reliable and informative building performance assessments. We argue that if we are to make progress in achieving our climate goals, we need to reframe built environment performance with a shift to net positive goals, while recognising the equal importance of human and environmental outcomes. This paper presents a simple conceptual framework for built environment performance assessment and identifies three performance gaps: (i) Prediction Gap (e.g., modelled and measured energy, water consumption); (ii) Expectations Gap (e.g., occupant expectations in pre- and post-occupancy evaluations); and, (iii) Outcomes Gap (e.g., thermal comfort measurements and survey results). We question which of measured or experienced performance is the ‘true’ performance of the built environment. We further identify a “Prediction Paradox”, indicating that it may not be possible to achieve more accurate predictions of building performance at the early design stage. Instead, we propose that Performance Gaps be seen as creative resources, used to improve the resilience of design strategies through continuous monitoring.