The Department of Environment and Energy and Sustainable Built Environment National Research Centre have released two reports about building energy performance.

Closing the Gap between Design and Reality of Building Energy Performance

Closing the Gap between Design and Reality of Building Energy Performance explores the “Building Energy Performance Gap” (BEPG) in commercial buildings in Australia – wherein discrepancies occur between the design and reality of energy performance in buildings. The report finds that factors across the entire building life-cycle contribute to the BEPG. Based on the interviews of 28 experienced professionals and two case studies, two strategic frameworks have been developed to address the BEPG:

1. Framework to Address Design and Construction Stage Factors of BEPG: This Framework outlines: (a) Strategies for Better Regulation; (b) Strategies for the Project Team; (c) Suggestions for Training
2. Framework to Address Operational Stage Factors of BEPG: This Framework outlines: (a) Monitoring, Tracking and Fine-Tuning; (b) Collaboration with Occupants and Lease Agents; (c) Facility Managers’ Training and Support; (d) Better Documentation of Building Services; (e) Energy Efficiency Tax Incentives

Building Energy Performance Gap Issues: An International Review

The second report, Building Energy Performance Gap Issues: An International Review, offers a literature into the BEPG. Key findings from this review include:

• The performance gap is more significant in non-residential buildings, with smaller measured performance gaps in residences
• A major issue is the disconnect between the tools that are being used to identify the gap and their original intent
• There is no consistent estimate of the magnitude of the gap found across all of the sources reviewed.
• There is more that needs to be understood about the “prebound” effect, such that in “energy wasting” (often older) buildings the actual energy consumption is generally lower than predicted, whilst predicted energy use in low-energy buildings (or deep energy retrofits) seems to be subject to a bias toward overestimation of the energy reduction/savings
• the performance gap is not only a technical problem but also has behavioral components

The report outlines two major opportunities to address the performance gap: (1) more accurate predictions of expected performance, using assumptions more relevant to the expected building occupancy and operation, and (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.

It suggests two key policy areas minimizing the performance gap:

• greater transparency of operational/measured energy performance (and not just relying on predicted performance through modeling);
• outcome-based policies that essentially regulate the operational performance of the building.

More information on Closing the Gap between Design and Reality of Building Energy Performance here

More information on Building Energy Performance Gap Issues: An International Review here