Net zero energy ready buildings in Canada
The end-goal of Canada’s proposed 2020 national model codes is that all new buildings will be built to net-zero energy ready standards by 2030, a commitment the federal, provincial, and territorial government, in consultation with Indigenous stakeholders, outlined in the 2016 Pan-Canadian Framework on Clean Growth and Climate Change (PCF).
But what is a net-zero energy (NZE) building? Is it the same as a net-zero energy ready (NZEr) building? The following section provides an overview of what NZE and NZER buildings are, the benefits these buildings can provide, and how NZE/NZEr can be achieved.
What is a net-zero energy ready building?
A NZE building is a building that can produce as much clean energy as it consumes. According to Natural Resources Canada, they are expected to be 80% more energy efficient than a new building constructed to today’s building code minimum. They use on-site (or near-site) renewable energy systems to produce the remaining energy they need.
A NZEr building is one that is designed, modelled and constructed the same as one that is NZE, but does not yet have on- or off-site renewable energy components in place.
A core aspect of net-zero energy “readiness” is the use of improved air sealing, increased insulation levels, and high-performance windows and doors to reduce thermal demand and facilitate appropriately sized space and water heating equipment.
Source: Adapted from Efficiency Vermont
In addition to using less energy and producing fewer greenhouse gas emissions, a NZE or NZER building also provides the following benefits:
- Greater comfort: strategic placement of the building, windows and overhangs, and increasing the airtightness of the building makes a NZE/NZEr building less drafty, quieter and less prone to uncomfortable temperature swings.
- Healthier indoor air quality: Rather than relying on a leaky building envelope that allows contaminants, uncontrolled moisture, and unconditioned air into the living space, an airtight NZE/NZEr buildings use Energy Recovery Ventilators (ERV) or Heat Recovery Ventilators (HRV) to provide supply fresh air without wasting energy.
- Resilience: NZE/NZEr buildings are better able to withstand extreme weather disruptions and provide a refuge during periods of shocks such as a prolonged power outage or other emergency. NZE/NZEr buildings can maintain a livable temperature longer thereby keeping occupants safe in extreme weather. Balanced ventilation provides a degree of protection in the event of wildfires or other events that introduce outdoor contaminants.
- Energy savings: Smart design with energy as an early consideration means less energy is used to keep your home warm in the winter and cool in the summer. This often leads to lower energy bills that help offset any increased costs associated with additional energy efficiency measures.
- Higher resale and rental value: NZE/NZEr buildings command a market premium not only for their increased comfort or lower energy bills but also because they are more durable.
- Smaller ecological footprint: Fewer greenhouse gas emissions and reduced energy use are a clear benefit. A more thoughtful design can also result in fewer resources used in the construction of your NZE/NZEr building.
In Canada less than 1% of buildings can be considered NZEr. We need to quickly scale up the number of NZEr buildings constructed each year through the adoption of ambitious NZEr building codes.
Not only will this help reach our global climate commitments, it will have the benefit of generating investments in our buildings sector while offering good local jobs in the clean economy for all Canadians.
High-performance building basics
NZE and NZEr buildings are typically achieved through improvements to the building envelope that reduce the overall energy consumed in the building. Measures such as more insulation or better performing windows, also provide enhanced comfort to building occupants, as well as greater durability of the structure and increased resilience in the event of power outages, forest fires or other catastrophic events.
A common misperception is that these measures are unnecessary given the proliferation of low-cost renewable energy. And yes, renewables do play an important role in reaching NZE buildings but only after energy loads have been drastically reduced through energy efficiency measures such as those described above.
Advanced energy codes such as the proposed 2020 national model codes typically take an “envelope-first” approach that emphasize increased airtightness levels, increased insulation, better performing windows, or more efficient HVAC equipment. The benefits of this approach include:
- Improvements to the long-term durability of the buildings,
- A healthier and more comfortable indoor environment,
- Lower energy demands over the life of the building.
- Right-sized efficient, heating and cooling equipment can be used which can lead to lower equipment costs, and
- The building will be less likely to require costly retrofits in the future.
Building on these measures, building owners and occupants can reduce the energy waste in their buildings by selecting and using low-energy lighting, such as LEDs, and better performing EnergyStar® appliances and equipment.
Building beyond NZER, today
Building energy codes are a huge opportunity to leverage the places we live, work, play and gather as a tool for both reducing energy use and for decarbonization.
And, while today’s code-minimum buildings are more energy efficient and emit fewer emissions than those built-in past decades, meeting Canada’s international commitments and realizing a net-zero emissions future means there is still so much further to go even beyond the highest tiers of the proposed 2020 national model codes.
The incredible potential of Canada’s building sector can already be seen in cities such as Toronto and Vancouver where Canadian builders and designers are reaching Passive House Institute levels of performance, the most aggressive standard for high-performance buildings. The Passive House standard sets aggressive absolute targets for maximum energy use. Passive design measures such as extra insulation and air tightness are combined with heat recovery ventilation to reduce the need for complex technologies. These measures reflect four imperatives that drive the standards approach:
- Maximize operating energy efficiency.
- Meet operating energy requirements from renewable sources.
- Minimize embodied carbon.
- Do the first three things as rapidly as possible.
Over 85% of Toronto’s projected growth to be large buildings, particularly multi-unit residential buildings and commercial office buildings. This is why the focus of the Toronto Green Standard (TGS) is to have all new reach near-zero emission levels by 2030. The TGS requires similar performance levels to Passive House for large buildings at Tier 4, the level to which all new large buildings in the city will be constructed by 2030. Municipally owned buildings will be required to achieve Tier 4 in 2026.
Vancouver meanwhile, has moved ahead of the BC Energy Step Code with its own Vancouver-specific additional requirements and revisions. The City’s Zero Emissions Buildings Plan outlines its plan to transition to zero emissions buildings in all new construction by 2030. Vancouver’s plan includes stringent limits on emissions and energy use in new buildings. The plan mandates the majority of new buildings in Vancouver to have no operational GHG emissions by 2025. New buildings will be expected to have no GHG emissions by 2030.
The City of Victoria emphasized in its Recovery, Resilience, Re-invention – 2020-2041 plan that existing building energy efficiency standards such as Passive House and Net Zero are a good start but insufficient for the future envisioned. The plan recognizes the need to move quickly and ambitiously to achieve the City’s emissions reduction requirement in the built environment. The plan includes the creation of a Building Innovation Incubator to stimulate construction innovation for climate impact.
While terms like NZEr or “high-performance building” can sound daunting and even futuristic they are quite similar to our current code-built buildings. Canada has a rich history in the building science fundamentals behind the “how” of better performing buildings, and many of the skills needed are already in place.
There is a growing recognition that the steps to achieving NZEr comes in the time and attention spent on details. And, to help industry meet any gaps that may be in place there are a number of industry associations and educational institutions offering accredited training.
This project was made possible with funding from The Atmospheric Fund (TAF)
© Efficiency Canada 2021