Passive House is a holistic construction certification standard, allowing Certified Passive House professionals flexibility to determine the most suitable building geometry based on usage and location.
Passive House explained in 90 seconds
Ever wondered if your heating or air conditioning in your house is really necessary? Passive House (Passivhaus) is a design approach to buildings that reduces the energy required drastically. This video explains briefly in 90 seconds how it’s done.
It was aimed to build energy efficient, airtight homes which would also provide healthy and comfortable indoor climate using well known construction physics. By minimising the energy use within these homes, by up to 90%, the costs to the homeowner would drastically reduce while also having a lesser impact on the environment. A win-win for everyone. These homes would be required to be built with such high quality from start to finish, that they are potentially be future-proofed. By taking into consideration every aspect of the building, the indoor climate will be healthy and comfortable to occupy.
The Passivhaus Institute has set forth following stringent performance targets for the heating and cooling:
Thermal performance | Maximum value | Example of a 100m2 dwelling |
Space heating demand & cooling demand Or | 15 kWh/(m2 yr) | Max. 1,500 kWh per year to heat (or cool) the dwelling. Can cost as little as $81.00 per year. |
Space heating load And | 10 W/m2 | Max. 1kW of heat source needed for the coldest time of the year with no solar gains. This is comparable to about 13 candles. |
Limit of overheating risk | Max 10% of time | Not more than 36 days per year the indoor temperature is allowed to be above 25°C. |
The attitude makes all the difference
In our industry environment focussed on flashy appearances and steeped in a sell-and-run mentality, Passivhaus tries to establish very different values, revolving around real and lasting performance.
Generally, the performance values of all materials, that all calculations are being based on, should be realistic figures, as installed and as verified by a third party. All materials used should be of lasting quality, making it a worthwhile investment.
Does it cost more to build a passive building compared to a conventional equivalent?
In Australia, building energy standards are lower than in many parts of Europe, and it is relatively difficult to source some high quality components here. The extra cost will depend greatly upon design, size of project, quality of finishes and so forth, but typically a range of 10 – 20% should be prepared.
However, recent local social housing projects are suggesting very small additional costs.
The more large-scale window and door manufacturers bring high-performance products to the Australian market, economies of scale will drive down costs. The cost is usually offset by the massive reduction in energy bills, and the elimination of heavy mechanical heating and cooling units. With increasing energy prices, the question to ask yourself is ‘Can I afford not to build a Passive House’?