What is a passive house? We’re glad you asked. With so many buzz terms in the world of green homes and sustainable living, it can sometimes be hard to keep up. But the concept of a passive home is actually pretty simple when it comes to living a green lifestyle.
From heating and cooling to indoor air quality and ventilation systems, we take a look at what makes a passive house and why many people believe they’re the future of eco-friendly building. And if building your own home seems like a far off pipedream, check out our article on how you can make your own home more eco-friendly in easy and affordable ways.
What makes a home a passive house?
Been meaning to switch to a home that’s more sustainable? A passive house could help you do just that. In its simplest form, a passive house is a home designed to require minimal heating and cooling.
To be officially qualified, though, the International Passive House Association states that there is a list of requirements a home has to meet. Here are some of the recommendations the IPHA lists to ensure a home meets the passive house standard.
Thermal protection
It’s important to ensure your home is well insulated. All edges and connections must be carefully planned to avoid nasty drafts finding their way in. This way you’ll use less heating, meaning higher energy efficiency. Win!
Airtightness
Prevent moisture damage by keeping your house super airtight. Your home’s airtightness must be displayed with a pressure test where, according to the IPHA, the allowable air change can’t exceed 0.6 times a room’s volume per hour and the pressure differential is limited to 50 Pascals. Confused? We hear you – but finding the right company to carry out a “blower door test” will have you covered.
Ventilation
According to the IPHA, it’s important to invest in ventilation units with heat recovery. This is because they are vital when it comes to energy savings, in turn making them essential for energy efficient homes. Ventilation units with heat recovery ensure that the warmth carried by the exhaust air isn’t wasted, but initially transferred to the incoming fresh air without the two air streams ever mixing. Clever stuff!
Window glazing
To make your home as sustainable as possible, it’s important to use well-insulated window frames with multiple lip packing. The IPHA states that glazings should have “a high total solar transmittance (g-value) of at least 50% making a net heat gain possible during the winter”. That said, lower g-values may be used for very warm and sunny climates (which is useful for those of us living Down Under!).
Protection against mould
To protect a passive house from mould, it’s important to abide by all the above points. A great ventilation system, thermal protection and ideally triple Low-E glazed window panes with noble gas filling should be used (although, straightforward double glazing should suffice in warmer countries). If a passive house is doing its job properly, you won’t find any mould!
Why would I want a passive house?
There are many reasons why you would want to have a passive house, but the main reason is that they’re so environmentally friendly. Their design and construction mean they rely less on natural resources and heating energy, making them the number one choice for green living.
Another reason you might want to opt for a passive home is because of the money you’ll end up saving in the long run. Sure, a passive house will set you back initially – according to Ken Levenson of NY Passive House, building an average-sized passive home will typically add between 5 to 10 per cent to the construction budget – heating and cooling it will cost far less than other homes.
Another advantage of living in a passive house is that the inside temperatures tend to be more comfortable than in a traditional home. This is because the internal air temperature is so consistent, whereas non-passive homes tend to move between boiling and freezing. Plus, the air quality in a passive house is also far superior to a traditional home, due to the air being systematically circulated and filtered.
How is a passive house built?
The trick with passive houses is that they’re actually built like any other building. The majority of the same materials and methodologies that apply to a traditionally-built house also apply to a passive house.
The bulk of what makes a home have a passive design takes place in the initial design stages. The insulation of the home will be key in the early design, as well as how airtight the home is. The most important aspect of a passive house is that it should reduce wasted energy (and money).
Another misconception when it comes to passive houses is that they have to look outlandish or futuristic. This isn’t the case (although, there are some pretty awesome passive house designs out there!). Whether you’re after something classic, contemporary, rustic or polished, the fundamental principles of passive homes can be applied to any living space you choose. What stays the same is that the house will always have lower energy consumption.
How to get started
Whether you’re new to the idea of passive houses or have been toying with the idea of building one for some time, making the switch can have a huge positive impact on both the environment and your own time spent at home. Yes, the initial costs are high (building your own home, in general, is going to hit the wallet hard), but the long term effects for both the planet and your bank balance will make it worthwhile.
Now you know more about what passive houses are and how they're built, you’re probably wondering how to build one of your own. If you’re lucky enough to be in a position to build your own home (or dream to be one day!), Green Homes Australia is a great place to start, being the only internationally compliant Green Builder in the country. Otherwise, work with a smaller, more independent architect and builder to scope out the eco-friendly home of your dreams.
