With the climate an ongoing issue that needs to be addressed, taking steps to reduce our negative impact on the environment should start at home.
When it’s time to design and build our dream home sustainably, how can we build something that will do more good for the environment than harm?
The answer is passive design.
Passive design is building a home that is designed to be in sync with its surrounding natural environment as possible. The essence of passive design is the structure’s ability to respond to the natural environment around it, eliminating the need for artificial heating and cooling (and the pollution that comes from it).
With passive design you can harness the power of nature to create a home that’s more sustainable and environmentally friendly while also saving big on energy costs.
Why Passive Design?
The aim of passive design is to harness the climate to keep your home at a comfortable temperature year round, without the need for air conditioners or heaters. Temperature control accounts for around 40% of the average Australian household’s energy use, and hiring passive home builders will dramatically reduce this, and in many cases eliminate it.
We know reducing pollution from our energy usage helps to protect the environment, and with a passive design home, energy reduction will become just that, passive! Thanks to the temperature regulation of passive designs, there will be less of a need to turn on the air conditioner when it’s hot outside and the heater when it’s cold.
Passive Design Principles
The hallmarks of passive design can be broken down into these 7 elements:
Location underpins how your passive design will be structured, as the climate where you are will have a massive impact on how your home will work for you.
Melbourne climate, according to the Köppen climate classification, is part of an Oceanic climate that also includes most of southern and eastern Victoria. Passive design has to work for the climate that you’re in. A passive designed Queensland home would be ineffective in Melbourne and vice versa.
Where the home is placed on the site is very important when it comes to effectively controlling the temperature through passive design.
Generally for Melbourne conditions, a north-facing structure is the ideal orientation as it gives maximum sun exposure in winter to keep your home warm and maximises shade in summer to keep it cool.
Keeping in mind ideal orientation, it’s also important to consider the layout of the different rooms in the house. North-Facing rooms are ideal for living areas as they allow for all day sun, but keep in mind shading may be needed to prevent overheating in summer. East-facing rooms offer morning sunlight and cooler afternoons, making them ideal for kitchens and bedrooms.
West-facing rooms offer good afternoon light, but are more prone to overheating. South-facing rooms are generally not recommended for living spaces due to their poor light and heat retention, but can be utilised for garages, laundries and bathrooms.
Insulation acts as the barrier between a comfortable inside temperature and the outside temperature, and is required in the floors, walls and roof. Good insulation can reduce or eliminate the need for heating.
Insulation requirements will also depend upon the climate, as insulation may be required primarily to keep heat out or in. It also needs to work in tandem with other passive design principles, as a well-insulated home in the wrong location or with the wrong orientation or layout will create an ‘oven effect’ that overheats the home.
The use of shading such as eaves, awnings and plants can block up to 90% of the sun’s heat.
The aim of shade is to shield your home from the sun’s heat in warmer months while still being able to harness the power of the sun to heat your home in the cooler months.
This can be achieved by being aware of the sun’s angle in your location. Knowing this, your shading should be designed with the sun’s summer and winter paths in mind, keeping temperatures comfortable year-round.
In a place like Melbourne where the temperature can go between two extremes in a single day, thermal mass is what keeps your home from doing the same thing.
Thermal mass is the ability of a material to store heat energy. This means that when a warm day turns into a cold night, thermal mass will regulate heat when it’s hot and release it when it gets cold so that the temperature stays at a comfortable average.
Materials that have a high thermal mass include concrete, tiles, stone and bricks. Lighter materials such as timber have a lower thermal mass.
Passive homes are designed to maximise the natural air that can be allowed in the home
Preventing damp and mound, ventilation is utilised for passive cooling of the home. Passive ventilation is controlled mainly through windows and doors, and can also be controlled through purpose built vents.
Each of these elements work together to create a home that is as self-sufficient and comfortable as possible
An important consideration for passive design
Many passive design elements, such as insulation in particular, are added to existing houses. This can be very costly and ineffective if your house was not built with other elements such as layout and orientation in mind.
This is why the most effective passive designs, the ones that eliminate energy costs, are built from scratch with passive design the major consideration throughout.
At Green Edge we’re passionate about making the next generation of homes more sustainable than ever before. That’s why we’re committed to building passive house designs in Melbourne for environmentally friendly homes utilising the principles of passive design.
If you’d like to see how you can make your dream home have a positive impact on the environment (and your energy bill), get in contact with our passive house builders in Melbourne today.