Passive housing, while it might not be a household term in Australia just yet, has been around as a concept for quite a while. Every year, new housing construction firms with a strong focus on carbon-neutral construction, clean energy, and passive housing builds are popping up. But, building passive housing is not a challenge for the faint hearted, which is perhaps why the movement is yet to sweep the general residential construction market by storm. If Australia’s appetite for renewable energy is any indication, however, it won’t be long before passive housing becomes the norm. So, what’s all the fuss about?
What is passive housing?
A passive house is designed to integrate quality design and comfort with extremely low (or zero) energy consumption. Using the already tried and tested clean energy technologies making use of the sun, internal heat sources and heat recovery, passive housing makes traditional heating and cooling redundant; thus, saving on energy bills and making very little impact on the environment.
Drawing on natural energy sources and using thermal mass and heat recovery to their advantage, passive houses maintain a fairly steady ambient temperature all year round. The ventilation associated with a passive house also means that the air quality within the home can be much higher than in traditional houses, there is less penetration of allergens such as pollen and dust, and humidity is controlled more effectively. Not only does this mean less issues with the damp experienced in colder, wetter climates, but less uncomfortable humidity in more tropical areas. Passive housing is a solution for better living, no matter where in the world it’s utilised.
What’s all the fuss about?
The benefits of passive housing stretch far beyond comfort for the owners. Passive housing means that homes use around a tenth of the heating and cooling resources when compared with traditional building techniques, which equates to a huge reduction in CO2 emissions and an extremely low reliance on our finite fossil fuel resources. As the technology and building techniques improve with research over time, these dependencies will lower further. Furthermore, the quality of the construction and mitigation of the risks of degradation from humidity concerns, passive housing construction allows for much longer-lasting builds, needing fewer repairs and little maintenance. In a clean-energy hungry nation like Australia, it’s little wonder that interest around passive homes is growing. However, one thing holding back the industry, as always, is price.
Because passive housing is a fairly new and, some would say, experimental construction philosophy, there are inherent budgeting risks involved. There are a few brave souls out there, however, who are bucking this trend and taking matters into their own hands.
Justin O’Keefe of County Wicklow in Ireland is just one example. Having always held an interest in low-energy building, he decided upon a passive house for his new home construction in 2010. He was determined that he could build his passive house for what it would cost him to undertake a traditional build.
Overcoming a truckload of challenges along the way, including tradesmen who didn’t’ understand the passive housing philosophy or it’s requirements, Justin achieved what he set out to accomplish, and moved his family into their new passive house in 2011.
Being passive house certified
Of course, simply building a theoretically passive house is one thing, but having it certified a success by the relevant bodies is entirely another. The Passive House Planning Package (PHPP), developed by Germany’s Passive House Institute helps home builders to create a detailed plan of the passive housing construction and ensure that all requirements and quality controls are met. This planning allows for issues to be addressed in the planning stage. The elements considered include orientation, solar gain for windows, sun protection against overheating, cross ventilation in the hotter months, thermal bridge-free detailing, U-Values of heat loss elements, hot water usage, hot water heater type, airtightness and ventilation.
Thousands of homes have already been certified by the Passive Housing Institute and hundreds of these have subsequently been monitored and tested for their performance, including in the challenging climates of Scandinavian nations, for example. Nations which experience extreme cold are highly motivated to find solutions which mitigate heating costs and air quality concerns. Australians, however, are motivated by both extreme heat and cold, and rapidly rising energy costs. As the technology improves, prices fall, and more specialist passive housing building firms enter the market, we’re sure to see this phenomenon begin sweeping through Australia soon.