What's the difference between green design, passive design and sustainable design, and why does it matter?
Increasing greenhouse gases, global warming, climate change, fossil fuel instability, rising energy prices and taxes on energy consumption. These are just a few of the global headlining topics we hear about every day. Daily exposure to these issues has encouraged a rise in the conscious effort of smart designs that are considerate of future environmental impact. These smart designs take into consideration the already evident changes we are seeing in our world today, while also considering how we can lessen, or even stop, further damage to our environment for future generations to come.
Let’s take a look from the ground up.
What is passive design?
Passive design is an approach that takes advantage of the climate to maintain a comfortable temperature range within the home. This is achieved through the appropriate orientation of the house on its site to make the most of natural heating and cooling.
House orientation is the key component to passive design, with spatial zoning, thermal mass, ventilation, insulation, shading and glazing also being contributing factors. It is a relatively simple strategy, intended to keep summer heat out and winter heat in, moderating the temperature of the home for comfort all year round.
Passive design can be easily achieved with upfront thinking and planning during the design phase of a home build. The best bit is it’s free – this efficient design strategy relies solely on the sun and breezes to achieve thermal comfort within the home, with the added benefit of reducing the home’s operating energy costs over its lifespan.
To make the most of passive solar design, you must be in tune with how to operate your home. Know when to open and close windows to let breezes in or keep them out, while also knowing when to open and close doors, blinds and windows to let sunlight in or keep it out.
Knowing how to correctly operate your home through the seasons can lessen your environmental impact and ensure your home is performing at its peak. A five-star energy-efficient home requires a five-star user in order for it to achieve its full operating potential.
Knowing how to correctly operate your home through the seasons can lessen your environmental impact and ensure your home is performing at its peak. A five-star energy-efficient home requires a five-star user in order for it to achieve its full operating potential.
What is green design?
This is an approach to design and building that minimises harm to both human health and the environment over the home’s lifespan.
Green design is achieved through the combination of material selections, the build of the structure itself and the sustainable environment. This involves specifying building materials and resources that have low embodied energy – the amount of energy consumed by their production – as well as minimal impact on both the environment and the home’s occupants.
Materials with low embodied energy should be paired with materials with low (or preferably zer0) volatile organic compounds (VOCs) for optimum occupant health. VOCs are harmful chemicals found in a number of home building materials. The toxins released by these materials can be harmful as they pollute the air of the home over the materials’ life.
Low-VOC materials are becoming increasingly important with the rise in energy-efficient designs. In an energy-efficient design, a well-sealed building is ideal, therefore the toxins present in some building materials have no way of escaping from inside the home. Low-VOC materials ensure these toxins do not enter the home in the first place.
Consideration should also be given to the use of renewable energy sources to power a home, such as wind and solar, along with energy-efficient appliances. The efficient use of water through water harvesting, wise internal and external water use, and water-recycling measures should also be considered.
What is sustainable design?
To get an understanding of sustainable design, let’s first look at the definition of sustainability. Sustainability is the practice of not being harmful to the environment, depleting natural resources, and drawing on materials that are grown or produced sustainably, thereby supporting a long-term ecological balance.
Sustainability is about taking what we need to live now, without negatively affecting the requirements of future generations. If an activity is said to be sustainable, it should be able to continue forever.
When we talk about sustainable home design, we refer to homes that are designed to reduce the overall environmental impact both during the home’s construction and over its entire lifespan. The home should be designed and constructed in a way that meets the needs of the present generation, without compromising the ability to meet future generations’ needs.
A great way to explain the difference between sustainable and green design, which are closely-related design principles, is through the building product, timber. Timber can be a very green product, but it’s only a sustainable product if the wood is harvested from a forest with a sustainable forest plan, which ensures the forest isn’t depleted over time to eventually result in deforestation.
Why are sustainable designs important for homes?
Knowing that you are doing your part to create a sustainable future should be enough of a motivating factor to implement these design principles. However, a more evident payoff is the immediate savings you will see in the cost of running your home.
Many homes we are living in now that were built in the past 50 – or even five – years did not take into account our climate and environment. Up front, these homes required large amounts of energy and resources to be built initially. On top of this, the power used to run these homes is huge and often wastes energy, working against the climate and putting further unnecessary strain on our environment.
Basic passive design principles can be easily incorporated into your home design for no extra cost, and can reduce – or even eliminate – the need for auxiliary heating or cooling, which accounts for about 40 percent of energy use in the average Australian home.
With population growth on the rise, we have seen an increase in urban infill of existing developed areas. The less impact we can have on these pre-existing infrastructures, the more viable our population growth with minimal environmental effect is.
The new generation of homes we are building today will still be in use in 50 years’ time. A conscious effort needs to be made to implement these ‘environmentally friendly’ strategies in order to reduce the strain on the environment that population growth is causing. Without these small changes to the way we approach design, we will see further negative effects on our environment, possibly with irreversible consequences.
It is important to remember that we are not reinventing the wheel. These design principles have been around for many years and can be incorporated into your home design for little or no additional cost. There really is no excuse for not considering the environment in relation to your home – and the generations to come will thank you for it!
If future climate changes are taken into account during the design phase of a home, not only will this reduce the damaging effects houses will have on the environment over their lifespan, but it will also ensure the comfort of the occupants living within for many years to come.
Passive design, green design and sustainable design are all elements we’ve become used to hearing in light of this, but what do these words actually mean?