What is a Net Zero Energy Home?
As the world moves toward more sustainable building and manufacturing processes, we are starting to enter a metaphoric “golden age” of sustainable construction. We aren’t going to get into the politics of it – frankly, that’s way outside our scope – but we thought we’d chime in on the value and capability offered by a Net Zero energy home.
As a custom home builder, we have a unique approach to Net Zero homes. In the Belgravia series of homes, we utilized some really amazing technologies to create homes that are entirely net zero. We thought we’d talk a bit about that process in this post.
What is a Net Zero Energy Home?
A Net Zero Energy home uses a combination of energy and thermal efficiency paired energy-generation and storage.
The result is a home that produces as much energy as it consumes (annually).
Building Energy & Thermal Efficiency Into a Net Zero Energy Home
The first piece of the puzzle is on the conservation of energy. Energy is used in all parts of a home’s construction and operation, from the energy used to create the materials to the energy used to power the home.
Currently in Alberta, most energy comes from coal or natural-gas fired power plants. These sources of energy have a sizable carbon footprint; homes built to be as efficient as possible can minimize the carbon footprint they have by getting the most use and value out of the energy they consume.
Ways to Make a Home More Energy Efficient
- Insulated wall systems – Traditional homes have walls with insulation inside. However, these walls are typically made of porous materials and are rarely completely air tight. In homes striving for maximum energy efficiency, thicker external and internal walls integrate seamlessly into beefed up insulation.
Most wall/insulation combos have an NT R-rating (a measure of efficiency4) in the 14-17 range. Our Belgravia homes have walls with NET R-ratings as high as 56. The difference in heating efficiency and cost is significant.
- Insulated concrete form foundations – Insulated concrete forms (ICF) systems are forming systems with insulation already integrated. In addition to offering significant strength, ICF systems offer superior thermal efficiency. Using ICF systems on our Belgravia homes resulted in foundations with a R-40 efficiency rating.
- Heat-retaining windows – Triple pane windows offer significant efficiency compared to standard double pane windows.
- High-efficiency heating & cooling systems – Home comfort is as important in a Net Zero Energy home as it is in any other home. In order to provide maximum comfort without sacrificing livability or efficiency, we use ultra-efficient heating methods (such as electric baseboard heating, geothermal heating, and air-sourced heat pumps) that offer efficiency ratings as high as 400% (compared to an ultra-efficient furnace, which taps out around 98%).
Producing Sustainable Energy
Making a home energy efficient is one part of a Net Zero home. The other part is generating energy. Currently, the only cost-effective way to do this is via solar. Today, rooftop solar is light years ahead of where it was just a decade ago. It is possible today to produce more energy via solar than your home will consume, and the difference can either be stored or sold back to the grid.
Storage technologies – such as Tesla’s Powerwall – are just becoming available in the consumer market. In most cases, excess energy is sold back to the grid. When more energy is required from for the home than what it generates (such as during periods of poor weather or at night), the home will draw from the grid as needed.
The Future of Home Construction
As Alberta – and Canada as a whole – shifts towards sustainable development practices, Net Zero Energy homes are going to continue to come down in price and gain ground in popularity. As leaders in this space, we are proud to offer Albertans the latest technologies and construction methods in energy-efficient homes.