How can I make my home energy efficient?
1 Orientation to the sun
Passive design is when the design of your home takes into consideration the surrounding environment and maximises the use of sunlight and the local climate to produce a comfortable environment inside the home.
Passive design is a great tool when building an energy efficient home, as it can significantly reduce the need to power heating and cooling systems. This is a big plus, as heating in New Zealand accounts for approximately 30% of a home’s energy usage.
Passive design uses heat from the sun and cooling breezes to ventilate a building, regulating temperature in your home year round. It’s most easily achieved with new-builds, as you can orient the home correctly, maximising sunlight in winter and shade in summer.
The design of the roof, walls, windows and flow of the spaces inside your home will all have an effect. If executed correctly, it will result in a highly economic and efficient home. Check out this home in Germany, which rotates to harness the energy of the sun. It’s called the Heliotrope and is energy positive, creating more electricity than it consumes!
2 Insulate properly
After passive design, insulation is probably the most important element to home energy efficiency. One of the best things about insulation is that it can be retrofitted to existing homes, as well as being central to renovations and new builds. Correctly insulating your ceilings and walls reduces the amount of heat entering your home in summer, and contains warmth during the cooler months, saving you from spending money on energy escaping through your walls.
3 Double glaze your windows
Just as you need to insulate your walls and ceilings, properly insulating your windows will make an enormous difference to your energy usage. Windows are generally considered an energy drain, because heat travels straight through a single pane of glass.
Double glazing, however, which is made of two panes of glass with an air gap between, stops the heat flow, reflecting it back inside in winter, and back outside in summer. Contrary to what some people think, double glazing is not only suitable for cold climates. In fact, it’s equally as effective in the heat, preventing the sun’s warmth from penetrating inside.
Even better heat retention can be achieved if you combine double glazing with specially treated panes. Low Emissivity (Low E) glass reflects long-wave radiation, trapping in more warmth in winter, and blocking more of the summer sun’s scorching rays.
4 Embrace air flow
Ensuring your home has natural ventilation can mean the difference between a hot, unbearable night’s sleep and a cool, fresh home. With correct cross ventilation, an evening breeze and natural air flow can flush out built-up hot air. When designing, renovating, or replacing windows in your home, ensure you have openings opposite each other that allow air to move through the building.
In a narrow terrace home, for example, this could mean installing strong mesh security doors at the front and back, to allow air to flow through. You could install ceiling-height windows that can be opened at night during summer months for extra ventilation. Finally, installing ceiling fans can assist air movement through a home, allowing fresh air to circulate more quickly.
5 Install efficient appliances and fittings
Appliances in New Zealand are given an energy rating, which is clearly displayed on them. By choosing an appliance with a higher energy star rating, you can save a great deal of water, energy and money. Similarly, you can save by choosing efficient shower heads, toilets and LED light bulbs.
Canstar Blue’s latest review of NZ power companies compares them on customer satisfaction. The table below is an abridged version of our full results, available here.
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Canstar Blue NZ Research finalised in April 2021, published in June 2021.
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One super-simple way to reduce the heat your home soaks up is to provide proper shade to windows and outdoor areas. Adding a wide verandah to your home that is angled correctly will provide sufficient shade in summer, while still allowing the lower winter sun to stream inside.
You can also provide shade with outdoor blinds and awnings. These will protect your windows from sunlight, but can be retracted to allow the light to enter in the evening and during cooler months. There are plenty of other ways to add shade to your home, including outdoor sails and large deciduous trees, which provide shade in the summer and lose their leaves to let in winter sun.
Making your home more energy efficient doesn’t have to cost the earth. In fact, it can save you money in the long run, while helping the planet at the same time. It doesn’t matter if you’re renovating, extending or building a brand new home, by using these simple design principles you can create a stylish, economical and efficient home.