Net Zero Energy Homes
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Net Zero Energy homes are the epitome of high-performance buildings
A Net Zero Energy house is designed, modelled and constructed to produce as much energy as it consumes on an annual basis.
These sustainable homes strike the balance of reducing the amount of energy needed to operate a home with generating energy on site through alternative energy sources.
By meeting this energy efficiency standard, homeowners are awarded with significantly reduced operating costs, a quiet and more comfortable living space, health benefits including high indoor air quality, and the satisfaction of making a significant contribution to the reduction of carbon emissions.
During our design process, an energy model is used to optimize your home’s specifications and confirm that the new house or energy retrofit will achieve Net Zero Energy (or Near Net Zero Energy) with the most responsible use of financial and material resources.
For more information, check out these resource below:
Net-Zero FAQ: Answering Five Common Questions About Building and Owning a Net-Zero Home
Understanding the Average Canadian’s Annual Energy Consumption
Advanced Wall Systems Keep Your Home Airtight and Efficient
HP+ WALL SYSTEM
Developed by BASF, the HP+ Wall is engineered for strength, durability, and efficiency and is a solid option to consider when building a Net Zero Energy home. Effective R-values (how well a type of insulation can keep heat from leaving or entering your home) can range between R-25 to R-50 depending on Neopor thickness and type of cavity insulation.
The HP+ Wall includes the following:
- A combination of Neopor exterior rigid insulation, Wall-Tite spray foam, and batt insulation to provide maximum insulation levels.
- Fully sealed rigid insulation with Masterseal NP1 caulking and flexible air barrier tapes. This is placed on the exterior to prevent thermal bridging through wall studs.
- Spray foam insulation is installed on the interior face of Neopor, adding thermal performance, air tightness, structural rigidity, and vapour permeance protection.
DOUBLE-STUD FRAMING
Double-stud framing is when two walls are separated to eliminate thermal bridging and provide a deep cavity for high-insulation levels, a requirement in Net Zero Energy homes.
The exterior wall is used for structural load-bearing, and is separated from the interior for a total thickness of 12”-16”. Cellulose insulation is then compressed into the wall cavity to deliver effective R-values from R-42 to R-56 (well above Canadian industry standards).
A Strong Foundation
Insulated Concrete Form (ICF) foundations are a stay-in-place expanded polystyrene concrete forming system that delivers high energy performance and is superior to conventional methods.
With integrated air/vapour barrier and finish attachment provisions, additional framing and plastic vapour barriers are unneeded. Dimpled damp-proofing membrane is used underground to ensure basement dryness.
Depending on the results of the Net Zero Energy modelling, an additional layer of interior insulation on the foundation may be required to reach the desired amount of insulation. This could be done by adding a 4” thick layer of expanded polystyrene, installing a framed wall with batt insulation inside the ICF foundation. Both options result in a foundation with a NET R-40 insulation value, contributing to the overall performance of the Net Zero Energy house.
Air-Tight Windows
Most of the heat loss in a building escapes through the windows, so good windows are critical in a Net Zero Energy home.
Triple pane windows with a low-e film, Argon insulating gas, and insulating spacers between panes are a good choice. In Edmonton’s northern climate, the glazing should be optimized to encourage solar energy to flow into the home while insulating to reduce heat loss to the outdoors. High-quality frames with certified sealing systems are recommended.
Solar Electricity
Solar-electric systems use photovoltaic (PV) modules to generate electricity. The arrays can be grid-tied, meaning that the home will provide energy to the electrical grid during the day, while drawing from the electrical grid during the evenings or when the home needs more energy than can be generated.
Solar PV systems can also be connected to batteries to store excess energy. This opens up the opportunity to disconnect from the electric grid and eliminates the costs of line service charges from utility companies. Effect Home Builders office in Edmonton is disconnected from the electric grid using a PV system with battery storage.
Edmonton is a great place for using solar panels to generate electricity. Alberta has the distinction of being one of the sunniest places in Canada (not to mention the rest of the world), with more sunny days and more hours of sunshine than other provinces.
The Government of Alberta established guidelines requiring energy retailers to buy back exported power at a rate equal to the customer’s retail rate. Over time, this can offset the cost of your solar system making it a long-term, eco-friendly investment.
Passive Solar Energy
South-facing windows allow energy from the sun to be absorbed by the thermal mass of the concrete floor. This thermal mass gathers the heat energy in the daytime, releasing it in the nighttime hours.
Superior Insulation Products
Expanded polystyrene (EPS) is often used under the concrete floor in the basement. EPS is also part of the Insulating Concrete Form and is a method for adding additional insulation to the interior of basement walls. EPS is non-toxic, CFC-free, mould-free, and provides a stable insulating value that will not diminish with age.
A combination of insulation materials contribute to a well insulated Net Zero Energy home. For example exterior rigid insulation, Wall-Tite spray foam, and batt insulation are used in combination with the HP+ wall system to achieve superior energy efficiency.
High Efficiency Heating
There are various methods that can be used to heat a Net Zero Energy home.
GEOTHERMAL HEATING
Geothermal or Ground Source Heat Pump (GSHP) requires a higher initial investment, but with proper engineering and the right soil conditions it can run at approximately 250% efficiency leading to long-term energy savings.
ELECTRIC BASEBOARD HEATING
Electric baseboard heaters require a low initial investment however they are less efficient than other heating options. This option may be considered when the building envelope is very well insulated and air tight and the demand on the heating system is lower.
Electric baseboard heating is sometimes incorporated into Net Zero Energy homes with a large PV system which offsets electricity used by the heating system.
AIR-SOURCE HEAT PUMP
Air source heat pumps are a net-zero energy home heating option designed for cold weather climates. Efficiencies range from 100%-400% depending on outdoor temperature.
The Belgravia Green home in Edmonton is an example of a Net Zero Energy home heated by an air source heat pump.
Fresh Air Ventilation
High efficient Heat Recovery Ventilators (HRV) are very important in an air-tight Net Zero Energy home. These units provide fresh air by exchanging stale indoor air with fresh outdoor air. The incoming air is pre-heated by the exhausting air, recovering up to 88% of the heat. Electrical usage is low due to Electronically Commutated Motors, allowing the home to be extremely energy efficient while maintaining a healthy environment.
