Passive design is a set of sustainable building principles that take advantage of natural benefits, such as wind and sunlight, to reduce the need for heating or cooling in your home. While renewable energy is concerned with generating clean energy, the passive design promotes sustainability by reducing a home’s energy needs.
Your home’s position, insulation, windows, and location are all part of creating an effective and efficient passive design. Designing your home to take advantage of these benefits will not only make it more sustainable but can also cut up to 40% of your energy costs.
Windows are an important focus in passive design, as they allow heat to both enter and leave the home. This means that they represent the biggest opportunity for improving a home’s passive design.
In colder climates, glazing windows can help to trap heat but may contribute to overheating during summer. Specially designed window films can achieve the same effect of insulating in winter while reflecting heat and light outside the home to keep you cool in summer.
The size and position of your windows can also impact how much heat is let into your home. Depending on your climate, windows should be positioned to take full advantage of sunlight during winter and can be shaded or fitted with a reflective film to reduce heat in summer.
The orientation of Your Home
Depending on your location, positioning your home correctly can help you to take advantage of solar heat and cooling breezes.
In Australia, living areas should generally face north, exposing them to the sun in winter and allowing easy shading in summer. Kitchens and bedrooms, however, should face east, granting limited sun exposure in the mornings and protecting them from the afternoon sun. This layout will provide plenty of natural light to the main areas of your home and maximize the sun’s heat in winter.
Eaves, awnings, shutters, and plants can all help to block direct sunlight from entering and heating your home. As unprotected glass is usually the biggest source of unwanted heat gain for a house, this can mean a big reduction to your cooling costs.
When installed correctly, shading can block up to 90% of the heat from direct sunlight. It’s also important to position shade correctly in relation to the sun’s seasonal paths, so your home can still get sunlight in winter.
Insulation and Thermal Mass
Insulating your home properly can help to keep heat in during winter and out during summer. Walls, ceilings, windows, and floors can all benefit from proper insulation and will work together with shading and other methods to keep your home at ideal temperatures. Depending on your climate, insulation can be tailored towards prioritizing warmer winters or cooler summers.
Thermal mass differs from insulation as it doesn’t trap heat but instead slowly stores and releases it. High-density materials such as concrete, bricks, and tiles all have a high thermal mass, meaning it takes a lot of heat energy to change their temperature. Buildings with a high thermal mass are ideal for climates with hot days and cold nights, collecting heat during the day and releasing it during the night.
Designing for the Australian Climate
When building or retrofitting your home to take advantage of the passive design, your local climate should always be taken into account. Those living in northern parts of Australia, for example, won’t normally need heating and can focus their passive design on reflecting heat and cooling their homes. For those living in changing temperate climates, the challenge will be to design around these seasonal changes.
Reclaiming energy through solar panels is also a popular design choice in Australia, due in part to the large amount of sun exposure the country receives annually. Integrating sustainable and renewable energy sources into your home can also help to reduce costs.
Whether you’re still planning or already living in your home, passive design principles can help you make the most of natural resources, work with your environment and reduce your energy needs.