Energy-efficient home initiatives have been building momentum in Canada, and most Canadians have heard of high-performance building standards like BuiltGreen Canada, Net Zero and Passive House. Canada’s commitment to the Paris Climate Accord is to be carbon neutral by 2050, with a 40 percent reduction by 2030.

According to the Liberal Party website, “In order to achieve net-zero emissions by 2050, we have to retrofit almost every building in Canada. This presents a real opportunity to kickstart a vibrant retrofit economy, with good middle-class jobs in all our communities.”

Building retrofits offer the opportunity for the construction industry to reposition itself as a career path that requires high-level skills on both the trade and design sides. The Liberals are committed to accelerating the development of the national net-zero emissions model building code for 2025 adoption. They are pushing for provinces and territories to require EnerGuide labelling of homes at the time of sale.

Under the 2030 Emissions Reduction Plan, the Canada Greener Homes Loan program will receive an additional investment of $458.5 million from the Canadian Government. The Canada Greener Homes Loan program and 2030 Emissions Reduction Plan are designed to assist Canadians in reducing emissions, saving money on retrofits and heating and cooling costs, and stimulating high-paying jobs in the economy.

Adoption of the ‘National Energy Code of Canada for Buildings’

The 2020 edition of the National Energy Code of Canada for Buildings (NECB) was an important step towards achieving Canada’s goal of Net Zero Energy Ready (NZER) buildings by 2030. Canadian provinces and territories have chosen to adopt the code as is, or with minor changes to adapt them to regional needs.

Some provinces and territories added sections from the National Energy Code to their provincial building codes. Four provinces have specific energy building codes to supplement their provincial building code regulations:

• National Energy Code of Canada for Buildings 2017, Government of Alberta
• BC Energy Step Code, Government of British Columbia
• Manitoba Energy Code for Buildings and Manitoba Green Building Program, Government of Manitoba
• Energy Efficiency Building Code Standards and The New Brunswick Energy Blueprint, New Brunswick Department of Energy

Retrofitting to net zero energy is not just about owning a “green home” or a house with solar panels. Net zero energy principles combine advanced design and superior building materials, to give you a home that’s energy-efficient, affordable to live in, extraordinarily comfortable, healthier, quieter and sustainable.

What is net zero ready?

Again, it is the goal of the provincial and territorial energy codes to achieve Net Zero Energy Ready (NZER) buildings by 2030, or 2032 in British Columbia’s case. But what is “net zero ready”?

A net zero ready building is the same as a net zero home but without a sustainable energy source. Your home will be so efficient that it could be upgraded to net zero simply by adding a solar panel system. As a homeowner, net zero ready means your home is already up to 80% more efficient than homes built to the standard building code.

Can my existing home be retrofitted to net zero?

Yes, net zero principles are not limited to new builds. They’re just like any home – only better. The planning and remodelling challenges could be extensive, but retrofits are doable for the majority of existing homes. Net zero retrofits adhere to the very same principles as new home construction.

Ultimately, achieving net zero energy is only the beginning. Carbon neutrality should be the ultimate goal, which would account for the total carbon emissions of materials and construction processes, in addition to the operational energy consumed.

Energy-efficient home design

Your net zero home begins with a smart energy efficient design, whether it’s a new custom build or a retrofit. A design-build contractor who specializes in high-performance homes, and is well-versed in net zero design, can help you get started with your retrofit project.

Energy modelling

Energy modelling software is a powerful design tool that provides a virtual simulation of your house, focusing on its energy consumption and the life cycle costs of the materials. It helps your designer or architect identify the most cost-effective measures for achieving zero energy in your home.

Modelling will be conducted at various stages of the design process, allowing your designer to analyze the energy impact of different design choices.

Sealing the building envelope

Thoroughly sealing the building envelope is the first step in retrofitting a net zero home that will be protected against air and moisture ingress. Sealing the building envelope of your home requires tight-sealing energy-efficient windows and doors, additional insulation, caulking and adhesive sealing tape. A tight building envelope provides a high level of control over energy consumption, indoor air quality, humidity levels, temperature and the prevention of cold spots and drafts.

Eliminating thermal bridging, while super-insulating

The best way to prevent thermal bridging during an energy retrofit is to apply continuous insulation to the home’s exterior. Thermal bridging occurs when solid materials like wood allow thermal transfer between the exterior and interior. When insulation is only used between studs, this can result in thermal bridging across the uninsulated areas.

One of the most popular methods for creating continuous insulation and stopping thermal transfer is to install rigid insulation panels over the exterior. The original cladding, and sometimes the shingles, are removed. Insulated sheathing is applied to provide moisture control and then the rigid insulation panels are installed to form a continuous barrier between the sheathing and cladding. Continuous insulation is sometimes applied to the inside of the home instead.

Proper ventilation

Since the building envelope of your net zero home is airtight, the retrofit must include a continuous source of clean air to keep it dry, healthy and comfortable. ERV (energy recovery ventilation) and HRV (heat recovery ventilation) systems are designed to expel stale air while reclaiming the heat from the exhaust stream.

HVAC system with air and drain water heat recovery

If your home has an old, inefficient forced-air furnace or central heating system, it’s time to install a highly efficient HVAC (heating, ventilation, and air-conditioning) system. Ductless heat pump systems are far more economical to operate than geothermal heat pump setups. Air and drain water heat recovery devices can recover energy that’s usually lost through air and wastewater exhausts.

High-efficiency appliances and LED lighting

Upgrading to Energy Star® appliances that are protected against “phantom” energy loads should be considered essential. Nearly half of a net zero energy home’s energy consumption goes to heating and cooling the air and water, so outdated appliances can make up roughly 60% of that amount.

Sustainable solar energy

You can transition from purchasing electricity from your hydro utility to solar energy in two or more steps. Many homeowners choose to complete a net zero retrofit in two stages. They will make the building envelope airtight, and install continuous insulation and windows, to bring their home up to net zero ready. And then when they are financially ready to continue, they’ll have a solar panel system installed.

A smart control panel

Smart meters are an important component when pursuing net zero. Smart control panels can better track the performance of your solar panel micro-generation system, tracking the surplus energy you’re feeding to the grid and the power you’re drawing from it during the dark winter months. Your smart energy dashboard can turn lights off when you leave the room, monitor your energy consumption, manage appliance usage and help pinpoint phantom energy loads and offer superior performance when maintaining electric vehicles. By helping your family change energy use behaviours a smart energy dashboard or app can potentially lower your bills.

The importance of net zero retrofits in reducing Canada’s carbon footprint

According to 2021 data from the Canada Mortgage and Housing Corporation, roughly 286,000 new homes are currently built each year in Canada. The Liberal government has promised to build about 400,000 homes annually for the next decade, to partially offset the country’s rapid population growth due to immigration.

Steve Mennill, chief climate officer for Canada Mortgage and Housing Corp. in Ottawa says, “Energy efficiency in new home construction is building momentum, but retrofitting older homes is of utmost importance. We only add about 1.5 percent to our housing stock every year, so to reach a carbon neutrality goal only through new housing is not sufficient. We have to upgrade our existing housing.”

The takeaway

Depending on your climate zone, the type of house you own, its age and condition, and the materials and systems already in place, your home may be a good candidate for an energy retrofit.

Net zero retrofits can significantly increase the value of a home, making it future-proof in today’s rapidly changing economy. A high-performance home has better-insulated walls, roof, and the envelope as a whole, which makes it more durable, resilient and healthier to live in.