Sustainable houses are designed in a way that minimises their environmental impact. By building them from eco-friendly materials, reducing waste during the construction process and making their energy and water usage more efficient, it’s possible to create a home that produces a significantly smaller carbon footprint over the course of its lifetime.
The benefits of sustainable housing extend beyond preserving the environment. Their efficiency means lower water and energy bills; “green” materials are often free of the potentially harmful chemicals found in conventional building supplies; and increasing demand for sustainable homes means that they attract higher values than traditional houses.(1) Types of houses like modular homes are an example of sustainable houses.
Many people are looking to completely remove their homes off-grid. Whether you want to create an entirely self sufficient house or just make it more environmentally friendly, there are a number of ways to reduce your home’s carbon footprint.
How to Make Self Sufficient and Sustainable Houses
Adopt a Passive Design
Passive design means considering the climate when designing a house, in order to reduce its energy usage. By strategically orientating a building and carefully designing its walls, windows, floors and roof, it’s possible to curtail undesired gains and losses of heat while harnessing natural weather factors like sun exposure and breezes.
Manmade heating and cooling units are responsible for roughly 40% of energy usage in Australian homes.(2) Effective passive design reduces or removes the need for auxiliary units, considerably lowering a household’s carbon footprint.
The principles of passive design are easiest to implement when building a new home, but they can also be applied when undergoing the type of renovation work required to upgrade a house or take it off-grid. Any substantial construction work to make a property more sustainable presents an opportunity to increase its “thermal comfort”.
Carefully Select Materials
A key tenet of sustainable building is minimising the unnecessary use of new materials. When renovating, this can be done by reusing materials from your existing home as much as possible.
Where new materials are required, using modular components can reduce waste by up to 52%(3). Where possible, sustainable materials should be chosen. This means materials that aren’t created using non-renewable resources, and whose existence doesn’t negatively impact the environment.
When considering the environmental impact of materials it’s necessary to account for their entire lifecycle, from their extraction and manufacture, through their period of use, to their eventual reuse or disposal.(4) A number of online databases provide detailed lifecycle assessment (LCA) information about a wide range of products and materials, enabling homeowners to make informed decisions before commencing building work.
Maximise Energy Efficiency
The average Australian household generates over seven tonnes of greenhouse gas emissions per year from its energy usage. Sustainable homes can combat this in two ways: first, utilise energy-efficient designs and technologies in order to conserve energy; second, obtain that energy from renewable sources.
If a house requires auxiliary heating or cooling units, they should be used as efficiently as possible. Zoning a centralised system stops it from expending energy to regulate the temperature in rooms where it’s not necessary. Carefully choosing the right system will reduce the environmental impact further. The most efficient reverse cycle air conditioners and gas heaters produce roughly one-third of the greenhouse gas emissions of electric heaters, while centralised hydronic systems can be heated using an inbuilt solar system.
Solar air heaters and heat shifters can also reduce the amount a house needs to be heated. For cooling, fans and evaporative coolers are the least energy-intensive options.
Obtaining energy sustainably is equally important. As the technology behind solar panels and batteries gets cheaper, a growing number of households are producing their own electricity using photovoltaic systems.
The newest systems have low running costs and are often price-competitive with electricity purchased through the grid. In many cases, the cost of generating electricity from a photovoltaic system over its lifetime is thought to be less than obtaining it from external suppliers.
Improved and cheaper batteries now allow households to store the electricity they generate and use it when their system isn’t operational, for example, at night, facilitating the trend of people taking their homes completely off the grid.
Minimise Water Usage
The average Australian uses approximately 100,000 litres of water per year, of which 12% comes from their home and garden. The solution here is also twofold: first, reduce household water consumption, then increase the effective recycling of water by households.
Reducing a home’s water usage is one of the most accessible methods of making it more sustainable. Installing water-efficient appliances such as taps, showerheads and toilets are an effective way of cutting household water consumption. The Australian Water Efficiency Labelling and Standards (WELS) scheme assesses the water-efficiency of products, providing a star rating alongside data on their levels of water consumption, making it easy to identify the appliances most suitable for sustainable homes.
Outside of the house, growing local plants and developing efficient irrigation systems can significantly reduce the amount of water that a garden requires.
Recycling water usually begins with rainwater collection. Collection systems comprising the roof, guttering, downpipes, rain-head and first flush diverters can effectively fill a water tank that feeds a supply system containing pumps and filters. The way recycled water is used determines the level of treatment it requires. The best systems can provide water suitable for all domestic purposes.
Many sustainable houses use recycled rainwater water for showering, clothes washing and toilet flushing while using an alternative supply for drinking water. Most Australian households ignore this valuable source of free water, instead using drinkable water for all domestic needs.
The central components of sustainable housing are simple. Most can be incorporated into your home gradually, as circumstances allow. You don’t need to move or rebuild your house to make it more environmentally friendly. Green renovation is easier than ever, and sustainable homes are the future.
- National Self Build and Renovation Centre: https://www.nsbrc.co.uk/news/5-benefits-of-making-your-home-eco-friendly/
- Your Home: https://www.yourhome.gov.au/passive-design
- EcoSpecifier: http://www.ecospecifier.com.au/knowledge-green/articles/sustainable-procurement-lca-the-way-forward/