Six Serious Misconceptions About Passive Houses
Passive Houses are one of the world’s leading standards for energy-efficient buildings. Originating from Germany in the early 1990s and with certification governed by the Passivhaus Institut, their key design principles include airtightness, good thermal insulation, thermal bridge-free construction and a Mechanical Ventilation Heat Recovery system (MVHR).
They also rely on the strategic use of high-performance windows and doors such as those manufactured sustainably by Thermotek.
However, there’s some confusion about the look, feel and construction of Passive Houses. From stuffy interiors to exaggerated costs, we investigate six of the most common misconceptions about passive houses and find that the reverse is true.
Misconception #1: They’re Claustrophobic To Live In
There’s a rumour that passive houses are stuffy and the windows practically glued shut. We’re happy to report this is nonsense.
You can certainly open the windows in a Passive House. In fact, passive design encourages the use of natural ventilation as one of the strategies to improve indoor air quality and reduce reliance on mechanical ventilation systems.
Passive Houses are designed to be well-insulated and airtight, which means that fresh air must be supplied to the indoor spaces through a controlled ventilation system – the MVHR. However, in addition to mechanical ventilation systems, natural ventilation can also be used to supply fresh air to indoor spaces.
Opening windows and doors can allow fresh air to flow through the building, especially during mild weather conditions. Additionally, some Passive House designs incorporate operable windows and skylights that are strategically placed to allow for natural ventilation and to take advantage of prevailing winds and air currents.
It’s worth noting that opening windows in a Passive House should be done with consideration to maintaining the building’s energy efficiency. For example, windows should be opened during times when outdoor temperatures are moderate and should be closed during extreme temperature conditions to prevent unnecessary energy loss. Additionally, it’s important to ensure that windows and doors are properly sealed and fitted to prevent unwanted air leakage when they are closed.
In a Passive House building, the ventilation system supplies the interior with constant fresh air, preventing the CO2 level from becoming too high. Thanks to the ventilation system expelling stale indoor air and replacing it with fresh air from outside, Passive House buildings remain mould and excess moisture-free. This, together with the comfortable interior temperatures that the heat recovery system and quality building envelope maintain, means that excellent air quality is guaranteed.
Misconception #2: They’re Too Expensive to Build
While passive designs may cost more initially than traditional builds that rely on cheaper materials and appliances like air-conditioning units, it offers significant energy savings in the long run, particularly if adhering to the Passivhaus standard, which can result in savings of over 90%.
In some extreme temperature areas like parts of Canada, building a Passive House may incur higher costs, but it’s also relatively easier to build one in more temperate climates like Australia.
Fortunately, there are now more affordable sustainable materials available, such as eco-friendly uPVC (unplasticised polyvinyl chloride) which we use at Thermotek instead of pricier options like thermally broken aluminium. This allows us to achieve excellent energy ratings without breaking the bank.
Our Thermotek Eco Series windows and doors system, made from aluplast’s 3-chamber uPVC profile, is a perfect solution for Australian homes that need to meet energy ratings without exceeding the budget.
Misconception #3: Passive Houses Are Freezing in Winter
The primary way that Passive Houses heat themselves is through the use of passive solar energy. Passive Houses are designed to minimise the need for traditional heating systems, although some may still require some form of heating during the colder months.
Passive solar energy is absorbed by the building’s south-facing windows and stored in high-mass materials, such as concrete or tile flooring, to release heat slowly over time. The house is also designed to have an airtight envelope to prevent heat loss and to have high levels of insulation to retain heat.
Additional heating can be provided by a small, energy-efficient ventilation system that uses a heat recovery ventilator (HRV) or energy recovery ventilator (ERV) to transfer heat from outgoing air to incoming fresh air. Some Passive Houses may also use electric or gas heaters as a backup, but these are rarely needed if the design is properly executed.
Overall, Passive Houses rely on a combination of passive solar design, insulation from the high-performance window and door systems like Thermotek’s, and ventilation systems to keep the interior warm during the winter months, while also minimising energy consumption and cost.
Misconception #4: Passive Design Only Works For Houses
Passive design principles can be applied to a wide range of building types, including apartments, offices, schools, and hospitals, among others. The principles of passive design are based on using the natural elements of a building’s environment, such as the sun, wind, and thermal mass, to maintain comfortable indoor temperatures year-round, without relying on mechanical heating and cooling systems.
For example, in apartment buildings, passive design strategies can include optimising the building orientation, incorporating high levels of insulation, maximising natural ventilation, using shading devices, and incorporating thermal mass into the building’s construction.
Passive design strategies can also be used in commercial buildings, such as offices and schools. For instance, designing buildings with large windows on the south-facing side to capture sunlight can help reduce the need for artificial lighting, while using thermal mass in walls and floors can help regulate indoor temperatures.
Thermotek supplies sustainable window and door systems for diverse passive design projects, from residential houses to commercial projects.
Misconception #5: Passive Houses Are Design-Limited
There’s a perception that Passive Houses are utilitarian and unattractive in design. This is not true at all! Passive Houses can certainly be beautiful, and in fact, many architects and designers incorporate passive design principles into their projects in a way that enhances the aesthetic appeal of the building. Passive design does not require a specific aesthetic or style, and with the right design and execution, a Passive House can be both energy-efficient and visually striking.
In Australia, there are many examples of beautiful Passive Houses, including this “Ravine House” in Sydney, which was designed by Rolf Ockert Design. The building features a unique, sculptural design that takes advantage of the site’s ocean views, while also using a range of passive design strategies to maximise energy efficiency and comfort.
For high-performance windows and doors that also look stylish, Thermotek Boutique Series presents visual styling and design flexibility for modern sustainable design. With an engineered 5-chamber uPVC profile by aluplast, the system also offers superior energy efficiency.
The modern selection of Architectural and Woodgrain colours ensures that this modern uPVC window fits perfectly into any architecture.
Misconception #6: Passive Houses Don’t Work in Australia
While Passive Houses were initially developed in Europe, the principles of passive design can be applied to buildings in any location around the world.
Many parts of Australia have a moderate climate that is conducive to passive design strategies such as maximising natural ventilation, using shading devices to control solar gain, and incorporating thermal mass into building construction.
In Australia, there are already many Passive Houses that have been built and are performing well. For example, in Melbourne, there is the “Sorrento House,” which is a certified Passive House that uses passive design strategies to achieve high levels of energy efficiency and comfort. It also has a stunning design with the strategic use of windows to capture solar energy.
Additionally, Australian building codes and standards are increasingly focused on energy efficiency, which makes it easier to incorporate passive design strategies into new buildings.
The 2022 updates to the National Construction Code (NCC) come into force in May 2023 and require new residential buildings to achieve a 7-star NatHERs energy rating. Passive design and the inclusion of Thermotek high-performance windows and doors can help meet these requirements.
While Passive Houses may still be subject to some confusion, if executed well they can be one of the most energy-efficient ways to build a home, lowering future energy output by up to 90%. They can also be incredible architectural projects, combining sustainability with style.
Thermotek’s mission is to make passive design and superior window and door systems accessible to Australian homes and projects. Our extensive local knowledge combines with German expertise to offer a fully customised service that harnesses the best in practice. In addition, our long-term partnership with Aluplast has given us access to the most innovative uPVC profile systems in the world.
Contact us today to talk about how our high-performance windows and doors can help you achieve an incredible passive design in your building project.