Building performance assessment - iiSBE Canada project to close the loop between theory and practice

iiSBE Canada, the Canadian arm of the International Initiative for a Sustainable Built Environment [iiSBE], an independent, non-profit group committed to advancing the sustainable building agenda within Canada, has taken up the challenge of developing the knowledge base about the performance of leading high-performance Canadian green buildings.

- Dr Mark Gorgolewski

As we address issues of climate change, peak oil, and resource depletion, actual building performance is coming increasingly into focus around the world. Green rating systems such as LEED and BOMA Best have traditionally focused on assessments at the design and construction stage, but there are many lessons to be learned from understanding how buildings actually perform once occupied.

In addition to benchmarking performance, a systematic assessment of the building once it is occupied can help the industry to understand how a building is functioning and identify problems or concerns that need to be addressed. This allows us to learn what works and what does not, and is particularly relevant to green and innovative buildings. It also helps to address building owners and policy makers interested in the real performance levels of their buildings, rather than modelled or theoretical performance.

Often there are significant discrepancies between predicted energy performance and resulting carbon emissions of buildings and their measured performance. Also, other factors such as water use and indoor environment and comfort targets may not be achieved. A key question is whether buildings live up to their potential, and what are the reasons for the differences between predicted performance and actual performance.

These discrepancies arise from a variety of reasons such as modelling methodologies, envelope and systems integration, construction quality, commissioning and handover processes, changes in functional requirements, other operational issues, motivation of occupants, and understanding of comfort. An investigation of such discrepancies can help designers integrate lessons from existing buildings into future projects, and can help building owners to improve the performance of their buildings.

Post-Uccupancy Performance
Post-Occupancy building performance evaluation is a systematic process of investigation and analysis to understand how a building is operating, compare it to benchmarks, and identify problems or concerns that need to be addressed. Unfortunately, it is presently little practiced in Canada but, internationally, regulatory and voluntary changes are increasing the urgency for designers and owners to know how to design better buildings that will produce better measured results.

In Europe, initiatives such as the Directive on the Energy Performance of Buildings [EPBD] and CarbonBuzz [www.carbonbuzz.org] are leading to a greater awareness of actual building energy use, and programs such as Passive House are partly based on actual monitored performance.
In North America this trend has been slower to materialise, but several initiatives are beginning to move the industry towards better understanding of actual building energy use. This includes the ASHRAE EQ [Energy Quotient] initiative, and requirements from some municipalities, such as New York, for large building owners to report on actual energy use and/or intensity.

iiSBE Canada project
In past years iiSBE Canada’s primary activity has been to coordinate Canadian participation in the Sustainable Building Challenge, a process that involves assessments of leading examples of green buildings internationally. The assessed Canadian buildings were presented with key performance indicators developed using the SBTool methodology at a series of World Sustainable Building Conferences. These assessments were based largely on design and construction information, and there is often a lack of information about how well these buildings perform in practice, and what lessons can be learned from their operation.

As a result the iiSBE Canada team plans to initiate a series of building performance evaluations of several Canadian green buildings using a set of key performance indicators. The aim is to understand their operational performance, compare this to predicted performance and to identify lessons for both their owners and for the industry as a whole.
Canadian building designers, owners, facilities managers, and researchers have a vested interest in improving building performance and in the establishment of building performance evaluation as a widely used tool for improving design practice and building operation.

The proposed research aims to benefit the whole sector and to enable real energy performance improvements to be achieved. So while specific feedback will be provided to building owners and design teams, iiSBE Canada intends that the general lessons from these assessments will be shared across the design and construction industry.
This should improve understanding across the sector and close the loop between theory and practice, thus making the task of delivering high-performing green buildings more readily and widely achievable, and to catalyze an increase in building performance evaluation in Canada.

This work will also be reported at the next World Sustainable Building Challenge conference SB 2014 in Barcelona where it is intended that a variety of international groups will report on studies focusing on real building performance and lessons from various building performance evaluations around the world will be exchanged.
Dr Mark Gorgolewski is in the Department of Architectural Science, Ryerson University, Toronto, and an iiSBE Canada Member; mgorgo@ryerson.ca . iiSBE Canada: http://iisbecanada.ca

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