Now there is a growing movement of sustainable houses, houses which use and produce less CO² emissions during construction and the lifespan of the house. But the question that struck me is: what is a sustainable house, actually?
What is a sustainable house?
There are three aspects which feed into the definition of a sustainable house: size, energy use, and lifespan.
It might come as no surprise that smaller houses use less energy to build and to run. So, the question of size is the first any aspirational builder would have to answer. How much space do I need to live? And getting the answer right is important because every square meter in a house uses energy and will thus contribute to the running costs of the house.
Size is also important to consider when designing the house. What is going to happen in the house? How many people will occupy it? A good design will incorporate these questions as well as leave room for any alterations to the house by future occupants.
Although size is an issue, a sustainable house does not mean a tiny house. It comes down to the building standard applied and its resulting energy consumption. Generally speaking, there are standard house, Passivhaus, and Zero Carbon house principles. These standards ultimately determine the energy use of a house during an occupation, however, not construction.
Speaking of standards, there are also other names for houses which could be considered sustainable houses: eco-homes and green homes which often come with a green roof and maybe rainwater harvesting, low-energy houses which focus on energy consumption above all else, and the various government initiatives such as Your home in Australia, Zero Carbon in the UK, and the Energy-efficient Buildings PPP on EU-level. All these names form a somewhat diverse set of sustainable houses.
The final aspect of what makes a house sustainable is its lifespan. Generally speaking, sustainable houses are built to last. A standard house today is built to last around 80 years. A sustainable house is built to last more than 100 years. With this lifespan in mind, questions like size and energy use are even more pressing to consider because the house will not ‘just’ last one generation of occupancy.
The sad news when it comes to describing a sustainable house is that no house will be 100 percent sustainable. And every house will have an impact on our planet. The idea behind a sustainable house is to reduce this impact as much as possible.