Sustainable Buildings, Beyond the Label

August 2012-073-2

By Thomas Bevan

Sustainable here, go green there: these slogans dominate real estate brochures around our cities. But what do these statements actually mean with regards to the net impact of buildings on surrounding ecosystems? What evidence is there that supports these claims?

A collaborative project between UBC’s Sustainable Building Science Program (SBSP) and theUBC Sustainability Initiative (USI) is attempting to find answers.  Using the Centre for interactive Research on Sustainability (CIRS) as a test bed, researchers are analyzing and modelling the hard numbers on what the energy throughputs have been over the last ten months.

CIRS, which opened last year, hopes to be one of the most sustainable buildings in North America. More specifically, its aim is for the building to be regenerative, meaning the amount of energy used would be less than the energy created and more emissions absorbed than produced.

Two new postdoctoral fellows have initiated a project that will generate a detailed energy model of CIRS. This model will be used to test and predict effects of different building materials and their corresponding impact on environmental systems connected to the building.

Mahdi Salehi has an engineering background in Iran. His speciality is in mechanical and aerospace engineering, specializing in thermo fluids. Belgin Terim Cavka is from Turkey; her background is in architecture and building physics, specializing in the effects of natural ventilation on thermal comfort.

Energy modeling is nothing new. All LEED (Leadership in Energy and Environ-mental Design) certified structures require that their design team predict what a building’s energy use will be before construction begins. However, the issue is that these predictions are not always accurate. Consequently, the buildings may perform below expectations.

This inaccuracy is frequent because of insufficient information at the design stage, making the predictive model incomplete and its parameters not representative of true real-world conditions. Because only a few buildings exist that are equipped with the specialized metering and monitoring systems required to measure detailed energy end uses, many energy models are forced to use these generalized input values for the parameters.

CIRS has over 3000 sensors that are continuously recording building performance. Some of the parameters measured include: lighting, temperature, heating and cooling (HVAC) system operation details, Volatile Organic Compound (VOC) levels, CO2, electricity production and consumption (photovoltaic transmitters), and water collection and consumption details.

Having this huge collection of data will allow the researchers to develop and refine models that are firmly grounded in empirical evidence. This will significantly increase the validity of energy models and allow the research team to narrow down the effects of specific building components and their contribution to overall energy use.