Thinking About Building a Net Zero Energy Home? Here’s What You Need to Know
The process of building a net zero energy home can seem overwhelming at first, which might explain why not many homeowners have attempted one before. Fortunately, with today’s building material manufacturers and all levels of government keenly interested in supporting and encouraging sustainable developments, building a net zero energy home is more do-able than ever.
What is a Net Zero Energy Home?
A “net zero”, “net zero energy”, or “zero energy” home produces or creates about the same amount of clean, renewable energy as it uses. This results in the homeowner spending significantly less money on their home’s heating, cooling, and general electricity systems. Net zero homes are extremely energy efficient, sustainable homes that are said to be 80% more energy efficient than a typical home (Source: Canadian Home Builders Association).
What Does a Net Zero Energy Home Look Like?
A net zero energy home is specially designed and built to reduce the net amount of energy used by a household to zero. The builder and architect achieve this by incorporating:
- energy efficient technologies
- sustainable, high-performance building materials
- a system that generates electricity on site
- intentional building design
In many cases, a net zero energy home is still connected to the electricity grid so that it can contribute the excess power it generates but doesn’t use back to the grid, and pull from the grid at times when needed. Throughout the course of the year, the amount contributed to the grid cancels out the amount that is taken from the grid, resulting in a net-zero energy use.
All the elements of a net zero home must work together in order to achieve the goal of net zero. Everything from the insulation, the quality of the windows, the elimination of drafts, and the presence of solar panels and rain barrels must be considered. The design of the home as well as its position on the lot also help towards achieving net zero.
Benefits of a Net Zero Home
- Energy bills become almost non-existent
- Protection from inevitable rising energy costs
- More durable home that is built to higher standards
- Rooms are kept at a consistently even temperature
- More insulation from the elements means more soundproofing against noise
- Filtered fresh air intake system protects against allergens
- Water-saving features help reduce water consumption
- Building methods reduce overall energy consumption
- You’re doing your part to conserve resources for future generations
Basics of Building a Net Zero Energy House
Below is a general overview of methods builders use to increase the energy efficiency of a home. When most of all of these methods are combined, the result just might be a net zero energy status for the home.
Insulation & Building Envelope
- Increase the performance (R-value) of the insulation.
- Ensure the insulation goes all around the building envelope, including the foundation and roof.
- Increase airtightness with a continuous, high-quality air barrier that passes the depressurization test.
- Ensure windows and doors are installed and sealed properly with no gaps.
- When insulating the foundation, go a step further with expanded polystyrene (EPS) insulation to prevent cold floors.
- Install a filtered mechanical ventilation system to bring in fresh air. This is especially important considering how airtight the home needs to be.
- A heat recovery ventilator (HRV) can recover energy otherwise wasted from outgoing exhaust air.
- Add a rooftop photovoltaic (PV) system to provide electricity. With this system you can connect to the grid, which allows you to have a back-up power source when needed. You might also be able to sell back your extra power.
- Add rooftop solar thermal panels for heating hot water, or look into the possibility of tapping into geothermal energy resources.
- Explore the use of wind and water turbines to generate electricity if there is insufficient sunshine available to you.
- Look into the possibility of a geoexchange system which pulls the energy from the ground or a body of water.
Water, Lawn & Garden
- Install water conservation systems.
- Add a rainwater harvesting system to collect plenty of water for the lawn and garden.
- A drainwater heat recovery system can recover energy used to heat wastewater.
- Choose landscaping that is hardy and doesn’t require a lot of water
- Swap the lush green lawn for a rock garden instead (depending on your climate).
- Plant some natural vegetation that doesn’t exceed the height of the building to shade the home’s exterior in the summertime, keeping it cool without impacting the solar panels on the roof.
- Find a vacant lot that gets lots of sun exposure if possible. This means considering the area’s existing trees and building heights, as well as what future development of the area could look like.
- Position the house on the lot where it will receive the maximum amount of sun exposure.
- The more roof, the more space for the best-placed solar panels.
- Add things like roof overhangs to prevent overheating inside the home in the summer.
- Choose appliances wisely, based on their energy-savings performance (EnerGuide) rating.
- Install windows strategically to make the best use of the free sunlight.
- Build with fewer windows, as they are less effective insulators than walls.
- For the windows you do use, consider going as high as triple-pane.
- Add window coverings to help control your indoor climate.
If you’re thinking about building a custom home in the Greater Victoria area, it might be the perfect opportunity to become one of the region’s first net zero energy homes. With building codes continuing to focus more and more on sustainable building choices, we won’t be surprised to see these types of homes become the norm in our lifetimes. In fact, the BC Energy Step Code is a provincial guide for builders and developers that is aiming to have all new buildings be net-zero ready by 2032.
Learn more about the history of Net Zero Energy homes in Canada through Natural Resources Canada.
The Canadian Mortgage and Housing Association also has a great resource on Net Zero Energy Housing.
Read more about the LIDA Construction custom home-building process, including how we charge and how we communicate the entire process with you every step of the way. Contact us today to get an estimate on your next project.