The Passivhaus is a German concept design for structures based on passive solar research done by the U.S. Department of Energy in the 1970s. Translated from German, the name literally means a “passive house,” and these structures are built with most rigorous design stipulations in an effort to be spend as little energy as possible when running a building.
The idea behind the passive house should be a starting point for the plans of all buildings, because it begins with a standard of energy-efficiency at its core. Passive houses aim to come as close to zero energy as possible, and though its success depends on many factors, the ambition of efficiency for the sake of environmental care is good for everyone.
Qualities of a Passivhaus
For a home or building to be a passive house, it must meet certain criteria. The guideline for these criteria are on a spreadsheet called the PHPP, Passive House Planning Package. A few of the qualifications that make a house passive are:
- No thermal bridges
- Heat-Recovery Ventilation, or HRV
- Optimal passive solar design
- High-performance doors and double glazed windows
- Leverages internal heat gain
Image Source: By Passivhaus_section_en.jpg: Passivhaus Institutderivative work: Michka B (talk) – Passivhaus_section_en.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=9586761
When a home is built with an efficient passive design, it can reduce the thermal load of a structure by 90 percent. In such homes, comfort is provided from a few sources:
- Passive solar heat
- Heat waste from electrical tools and appliances
- People’s indoor activities
The level of detail is exacting and would intimidate most Australian designers, builders and engineers. However, those working with the NatHERS system won’t be surprised by these prescriptive standards.
The Viability of the Passivhaus in Australia
The obstacles to passive houses in Australia involve airtightness, which has been a major difficulty for some of the nation’s contractors. There is some misconception that passive houses are like hermetically sealed boxes — the antithesis of the Australian lifestyle. In truth, Passivhaus provides an energy-efficient solution that allows for a comfortable indoor temperature.
The HRV systems take dirty air that’s exhausted from the structure and recirculates 100% fresh, filtered air so that, even in the heat of Australia, passive houses offer a sustainable and affordable solution to temperature fluctuations. The resistance to Passivhaus in Australia has been in part due to a fear that windows would forever be shut, but that isn’t accurate.
Experts who have experience in the design of passive houses suggest that when these structures are designed according to those exacting specifications, the opening and closing of windows is actually beneficial to the overall performance of the building.