Having a home that costs you almost nothing in electricity and heating may seem like a distant dream. But it’s possible with net-zero energy homes, also known as zero-energy homes.
They’re becoming increasingly popular, even here in Canada, where heating requirements are considerable. In addition to economic reasons, many are choosing to respect their environmental values.
What is zero energy consumption?
A zero-energy home produces as much energy as it consumes. In concrete terms, these homes already have a very low energy demand and can produce the necessary amount of energy by themselves. So there are virtually no bills to pay for heating and electricity.
In Canada, there is a certification program under the umbrella of the Canadian Home Builders’ Association (CHBA): Net Zero Home (NZH) and Net Zero Ready Home (NZRH).
Three components of net-zero energy homes
To achieve net zero energy housing, installing a few solar panels is not enough. To achieve this goal, three important components must be taken into account.
If a house or building is to achieve zero energy consumption, energy losses must be avoided as much as possible.
There is no perfect solution that works in all cases. However, strategies can include energy-efficient windows, insulation beyond minimum standards, a rainwater harvesting system, LED lighting, etc. These are sometimes called “airtight” houses with zero heat loss. Zero-energy houses are up to 80% more energy efficient than a standard house.
They can also be passive houses, meaning that their design and orientation to the sun are optimized so that they are heated as much as possible by the sun in winter while remaining cool in summer.
Because of its high efficiency, installing a heat pump is a common strategy for achieving a net-zero home.
To achieve zero energy consumption, the house must produce its energy. In most cases, solar panels are installed. Geothermal energy is also sometimes used, as are wind turbines. Surplus electricity can be sold to the utility if the house is connected to the Hydro-Québec grid. If the home is off the electricity grid, surplus energy can be stored in batteries.
Inhabitants’ consumption habits
Of course, even with the most ingenious design and efficient solar panels, achieving net zero requires the home’s occupants to do their bit. Depending on the situation, this may mean unplugging electrical appliances at night to avoid phantom loads. It also means choosing only Energy Star-certified appliances, monitoring water consumption, and using water-saving appliances. You should also avoid overheating in winter and over-cooling in summer.
For a new home
If you’re having a house built and aiming for net zero, you can apply certain principles to the construction itself. For example, you could choose a frame that uses less wood.
Other strategies can help, such as locating windows in the wall to retain heat and installing flashings to control water and mould where there are openings.
For an existing home
It’s perfectly possible to transform an existing house into a net-zero home. Of course, this depends on the home. Potential renovations include insulation beyond building code requirements, window changes, and heating system upgrades. Subsidies are available to help you make your home more energy-efficient.
Advantages of a net-zero home
The first advantage is the most obvious: your energy bills are extremely low with a net-zero home. Because your home produces its energy, you’re protected from fluctuations in energy costs.
Because this type of energy-efficient home is built to higher standards, the constructions are more durable. They are virtually airtight, making them very comfortable. Air quality is purer, thanks to the integrated ventilation system. Its insulation also works against sound. You won’t be disturbed by your neighbour mowing the lawn or having a party. It’s a home that offers greater comfort and tranquillity.
Disadvantages of a zero-energy home
The major disadvantage may lie in the price, especially if you have a conventional home that you want to convert. Renovations can be pretty expensive. You’re looking at tens of thousands of dollars. It’s a significant investment but well worth it!
Net-zero homes are already very popular in Europe, where electricity costs are much higher. They’re becoming increasingly popular here, even though they were virtually non-existent in Quebec a decade ago. Eventually, advanced net-zero home standards could become the general building norm. Whether you’d like to take on the challenge of reducing your home’s energy consumption to zero or you’d like to lighten your bills, don’t hesitate to contact us. We’ll be happy to help you with the heat-pump part of your project.