At Greensaver, we are passionate about protecting our planet. To halt global warming and leave a livable world for future generations, we must transition to a zero-carbon society as soon as possible. There are numerous ways to achieve zero-emissions, from switching to renewable energy to driving an electric vehicle. Another is building zero-carbon buildings.
What are Zero-Carbon Buildings?
In general, zero-carbon buildings display the following four characteristics:
- Over a year, the building operations emit net zero carbon.
- The building design prioritizes energy efficiency.
- The facility uses renewable energy onsite.
- The architects take into consideration the carbon emitted in the manufacturing of building materials.
How do They Work?
Zero-carbon buildings utilize various carbon reduction measures to achieve their zero-carbon status:
High-Performance R-Values for Roofs and Walls
The R-value refers to how well insulation resists heat flow. The higher the value, the better the resistance and thermal performance.
Zero-carbon buildings achieve a high R-value in roofs and walls at the detailing stage – when adding the finishing touches to insulation work. Builders ensure that insulation overlaps to cover all gaps and utilize air-sealing technology, such as caulking and weatherstripping, in all corners.
In traditional buildings, heat gain and loss through windows can account for 25-30% of residential heating and cooling costs. Zero-carbon structures avoid this problem by installing triple-glazed windows, which are significantly more energy-efficient.
However, this does not translate into fewer windows per building. Generally, zero-emissions buildings can have a window-to-wall ratio as high as 40%, allowing natural light to enter while maintaining high-efficiency standards.
Dedicated Outdoor Air Systems
Dedicated Outdoor Air Systems are heating, ventilation, and air conditioning (HVAC) systems with two separate systems: one for the building’s ventilation with outdoor air, and the other to handle the heat produced inside. Such a system uses less energy than a traditional HVAC system.
Building Automation Systems
Zero-carbon buildings use building automated systems to control their HVAC and lighting. For example, sensors automatically switch off lights when rooms become empty. Utilizing such intelligent systems reduces human-induced energy waste.
Zero carbon buildings most commonly use solar power as their primary energy source, one of the most affordable energy sources globally. It is also relatively easy to install and is a zero-carbon source of energy. Using it protects the building from fluctuations in the energy grid, such as extreme weather-induced power cuts.
Many zero-carbon houses also use passive solar design to aid heating. Passive solar strategies accumulate heat as the sun shines in through south-facing windows. Thermal mass materials, such as concrete, collect the heat and redistribute it gradually throughout the house.
Why are Zero-Carbon Buildings Important?
The construction of zero-carbon buildings is vital in the fight against climate change. Currently, buildings make up almost one-third of global carbon emissions. Due to the world’s growing population, buildings’ energy demand may increase by up to 50% by 2050. However, the transition to an energy-efficient, low carbon building sector could provide energy savings of 50%.
In Canada, 17% of emissions come from residential, commercial and institutional buildings. In 2016, the Canadian government created the Pan-Canadian Framework for Clean Growth and Climate Change. This framework includes a target that all provinces and territories approve a net-zero building code b 2030.
75% of the buildings built today in Canada will still be standing in 2030. Buildings not constructed to zero-carbon standards will either lock in future emissions or be expensively retrofitted down the line to align with zero-carbon legislation.
What are the Benefits of Zero-Carbon Buildings?
As discussed, zero-carbon buildings are infinitely better for the environment than traditional buildings. They emit less carbon in the construction phase by selecting low-carbon materials such as timber; and throughout the lifetime of the building with first-rate insulation, ventilation, and use of renewable energy sources.
Zero-carbon buildings are more comfortable than conventional buildings. Automated systems hold inside temperatures at a pleasant level, while excellent insulation reduces outside noise pollution.
There are also health benefits related to zero-carbon buildings. Their advanced ventilation systems and airtight insulation create fresh indoor air, free from outdoor pollutants.
Passive solar technology also requires a lot of sunlight to enter, filling zero-carbon buildings with natural light. Natural light has numerous health benefits, including increased vitamin D, better sleep, and less seasonal depression.
Zero-carbon offices are proven to improve employee performance. A study by Harvard University found that workers’ cognitive scores increase by 101% when working in a green building. Also, offices with clean air and high ventilation rates can improve employee performance by 8%.
Energy prices can fluctuate considerably and often increase yearly. Zero-carbon buildings avoid such fluctuations by producing their energy onsite.
The airtight construction of zero-carbon buildings also leads to less moisture. Consequently, there is less moisture and mould damage to repair.
Progress Towards Zero-Carbon Buildings
In Canada, the Canada Green Building Council launched the first Zero Carbon Building Standard in 2017, making carbon emissions the key indicator of building performance.
The 2019 federal budget also included $350 million towards a program called Low Carbon Cities Canada. This initiative included $183 million, specifically earmarked help Canadian cities reduce their emissions.
In 2018, mayors from 19 cities worldwide – including Montreal and Toronto – signed the Net Zero Carbon Buildings Declaration, committing that all new buildings will be zero-carbon by 2030.
Besides this, various countries worldwide have launched equivalent organizations to the Canada Green Building Council, to speed up the adoption of zero-carbon buildings.
Examples of Zero-Carbon Buildings
Evolv1: Waterloo, Ontario
Completed in 2018, evolv1 in Waterloo is Canada’s first zero-carbon building. It is home to two universities: the University of Waterloo and Wilfrid Laurier University.
The Joyce Centre for Partnership & Innovation: Hamilton, Ontario
Canada’s second zero-carbon building – the Joyce Centre for Partnership & Innovation – was built in Hamilton, Ontario, in 2019. It contains student study spaces, labs, and lecture halls for Mohawk college.
As demonstrated, the construction of zero-carbon buildings is indispensable if we are to limit the effects of climate change. Aside from the environment, zero-carbon buildings also have extra benefits, such as being healthier and more affordable to run than conventional buildings.
The building of zero-carbon buildings has accelerated in recent years, both in Canada and around the world. We are excited to see what the coming years bring for the zero-carbon building industry.