Building energy efficiency has been identified as a cost-effective opportunity to reduce energy consumption and greenhouse gas emissions and a variety of policies are being implemented to harvest this efficiency potential. However, there are growing concerns about a gap between predicted or expected energy consumption levels in buildings and the actual measured energy consumption in operation, both at an individual building level as well as in the building sector as a whole. The energy performance gap has been identified as an important barrier in achieving building energy policy goals, as a variety of reports have pointed out that anticipated savings from key building efficiency policies, such as building codes, may need to be significantly discounted due to actual post-occupancy building energy consumption being markedly higher than what had been predicted by building energy performance models.

Key findings

There are two opportunities to address the performance gap:

1. More accurate predictions of expected performance, using assumptions more relevant to the expected building occupancy and operation
2. Better management of the quality control process throughout the design, construction and operation processes to make sure that the design intent for greater efficiency is not lost at some point during the building’s life-cycle.

The policy areas that appear to hold promise for minimizing the performance gap are:

1. Greater transparency of operational/measured energy performance (and not just relying on predicted performance through modelling).
2. Outcome-based policies that essentially regulate the operational performance of the building.