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Net Zero Design - Mitigating Climate Change

The climate is changing, and it’s changing rapidly. To stabilize the climate, greenhouse gas emissions must be reduced by 40% to 70% from current levels by mid-century (Intergovernmental Panel on Climate Change-IPCC, 2014). The December 2015 Climate Conference in Paris achieved an unprecedented global agreement on climate action which came into force on November 4, 2016. The goal of the agreement is to strengthen the global response to the threat of climate change by keeping global temperature rise this century to well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius.

While the demand for energy will nearly double by 2050, the demand for water will also increase by over 50%

Our built environment can contribute significantly to reaching this goal. Buildings are responsible for about one third of carbon pollution in the US, and about one fifth of carbon pollution in Canada. This makes buildings the largest single source of emissions in North America. Worldwide, buildings account for about one third of energy-related emissions, and unchecked will continue to grow to meet the demand of population growth. Over 80 billion square metres of buildings will be built and rebuilt in urban areas by 2030. Total floor area is expected to increase globally by 127% between 2016 and 2050. Carbon reduction strategies are no longer just mitigation, they are critical adaptation measures if we are to stabilise the climate.

The concept of a Net Zero Energy or Emissions building is that it is a highly energy efficient building that produces on-site, or procures, carbon-free renewable energy in an amount sufficient to offset the annual carbon emissions associated with building operations.

There is growing consensus that all new buildings and major renovations should be net zero starting in 2030. This means that no buildings should be built below net zero standards beyond 2030. By 2050 all of our buildings both new and existing should be net zero. Decreasing emissions as the total floor area increases will require significant improvements in building energy efficiency, as well as adoption of low-carbon energy sources. As emissions from operational energy decreases, the carbon emissions from the materials used in construction will take on more prominence. Building designers need to be able to track, measure, and reduce the embodied carbon--the carbon emissions to produce, transport, use, and dispose of a material, i.e. from cradle to grave.

Finally, we should not forget that, while the demand for energy will nearly double by 2050, the demand for water will also increase by over 50%. At the same time, due to the predicted changes in climate, global water resources and water quality will reduce. Water use management and reduction strategies are also critical in our ongoing development.

The political will, the demographic growth, the urgent need to mitigate and adapt, combined with technology advances, provides us with an opportunity to understand, design, and deliver net zero buildings and retrofits to help curb climate change and meet the global target for temperature rise. We are committed to net zero design by 2020.

About the author:

Mark Porter, FIStructE, P.Eng., Struct. Eng., ENV SP is our National Practice Leader, Building Services based in our Burnaby office. Mark has over 20 years of experience in structural engineering and building design across Canada, the UK, US, and the Caribbean. His passion for sustainable structures has led to his involvement with the Canada Green Building Council, the Living Future Institute, and the Institute for Sustainable Infrastructure. He is Chair of APEGBC’s Climate Change Advisory Group.