Does The Passive House Standard Work?
Over the past few decades, there have been exponential leaps and bounds in sustainable building, with serious investment in green design. Architects, builders and homeowners are now considering the environment as an important part of the construction process, thanks in part to the increased energy efficiency measures that have been incorporated into the Australian National Construction Code (NCC) 2022.
Passive Houses are at the vanguard of green design for both commercial and residential projects, seen as a strategic way to reduce running costs and improve the planet by reducing carbon use and output.
However, some sceptics point to more expensive building materials as a negative of Passive Houses. At Thermotek, we believe that Passive Houses are a great way to save money in the long term, as they’re an excellent way to lower utility bills and are well-suited to the Australian climate. A slightly higher investment at the outset is more than offset down the track.
We also offer affordable window and door solutions that also meet the strict criteria of passive design. Our products are engineered in Germany and sustainably manufactured locally in Australia.
Let’s take a look at the ways in which Passive Houses work well as a sustainable building solution, and how the ‘cons’ are offset by long-term advantages.
First off, What Makes a House ‘Passive’?
The concept of the Passive House comes from Germany and the Passivhaus Institut, founded by Dr Wolfgang Fiest. Fiest devised a set of design standards that create sustainable homes, very low in energy usage and also offer excellent ventilation and air quality for comfortable living.
The calling card of a Passive House is that the building envelope and materials maintain thermal comfort, not electricity and carbon-hungry devices.
There are 5 key design principles that Passive Houses adhere to:
- Airtightness – a very limited amount of gaps and cracks, stopping drafts and/or air leakage.
- Good Thermal Insulation – thus improving comfort and reducing condensation.
- Mechanical Ventilation Heat Recovery (MVHR) – an MVHR system regulates and filters air quality without the need to open windows.
- Thermal Bridge Free Construction – any penetrations through insulation (called ‘Thermal Bridges’) are kept to a minimum.
- High-Performance Windows – to be truly passive, houses must have high-performance windows that offer good levels of insulation, with double or triple glazing. They should also be sized to allow for the right amount of solar energy in winter and summer.
What Challenges Come With Building Passive Houses?
1. Managing Costs
Real sustainable design can be a little more costly than traditional builds that use cheaper materials and depend on electricity and appliances such as air-conditioning units. However, while costs may be slightly higher initially, ongoing energy savings of over 90% are possible when the Passivhaus standard is adhered to.
Building costs can also be higher for Passive Houses in places with extreme temperatures, such as -40 winters in Montreal. However, building Passive Houses in relatively temperate climates like Australia is much easier.
In addition, it’s now possible to keep costs down with more affordable sustainable materials. At Thermotek, we use eco-friendly uPVC (unplasticised polyvinyl chloride) instead of more expensive sustainable materials such as thermally broken aluminium, making it possible to achieve an exceptional energy rating without an exorbitant price tag.
Our Thermotek Eco Series 3000 windows and doors system is produced from the global German design and engineered 3 chamber uPVC profile by aluplast.
The Eco Series 3000 provides the ideal solution for Australian residences that are required to meet energy ratings without breaking the budget!
2. Lack of Customer Knowledge
Another challenge can be a general paucity of knowledge in the market and the need to educate both builders and clients regarding how Passive House design works. It means that future adjustments to the design need to be monitored and that it is extremely important to work with an experienced contractor. For example, accidentally creating thermal bridges can have a major impact on energy efficiency in Passive Houses.
How Do Passive Houses Work to the Residents’ Advantage?
1. Massive Reduction in Energy Usage
One of the biggest benefits of Passive House Design is the significant reduction in utility bills, without a loss of comfort. Passive Houses consume up to 90% less energy than traditional buildings that are very dependent on carbon-hungry conditioning systems. Passive Houses achieve this through clever solar design, an airtight building envelope and outstanding insulation. Energy-efficient windows and good ventilation are also key.
2. Passive Houses Exceeds The Australian NCC 2022 Energy Efficiency Requirements
Passive House design requirements mean that these types of designs are more likely to meet building code requirements.
In Australia, the 2022 updates to the National Construction Code (NCC) put increased emphasis on energy efficiency. There were two key changes to residential works, including apartment buildings:
- Thermal performance requirements were raised to 7 stars under the Nationwide House Energy Rating Scheme (NatHERS).
- New homes must meet a new Whole-of-Home Rating. This applies to heating and cooling, hot water systems, lighting, swimming pool and spa pumps, windows and doors. Renewable and sustainable energy systems, such as solar panels, aren’t mandatory but can be installed to keep a home’s energy under budget.
Passive House design standards help meet these requirements by massively reducing the amount of energy being used.
In addition, any energy that is needed can be supplied by renewable energy sources.
3. Passive Houses Are Comfortable
Passive Houses are uniquely comfortable dwellings. When properly constructed, they have no cold drafts and a consistent temperature all year round. Not only are there minimal heating and cooling bills, but the indoor environment is also healthier for all residents.
Thanks to the mechanical ventilation systems, Passive Houses boast excellent air quality. During summer, the exhaust air removes heat from fresh intake air. During winter, the exhaust air supplies heat to the intake air. These mechanical systems are compact and unobtrusive because their design capacity is lower.
4. Design Flexibility
Thanks to great advances in the look and feel of sustainable materials in recent years, excellent design flexibility is possible with Passive Houses. One complaint that has been levelled about Passive Design in the past is that, depending on location, the size of windows can be limited as solar radiation needs to be regulated.
However, this can be managed through thoughtful design. For example, if the owner wants large windows, these can be triple-glazed with extra insulation added to the surrounding walls.
When it comes to designing Passive Houses, one of the most important facets is to work with experienced suppliers like Thermotek who understand the design standards and can provide a much wider selection of design materials that will suit any style.
Our Boutique Series 5000 presents visual styling, superior energy efficiency and maximum design flexibility for modern sustainable designs. The selection of Architectural and Woodgrain colours ensures that it fits perfectly into any project.
Specifically designed and tested for the Australian climate the Boutique Series 5000 windows and doors cater for all types of Green smart residential new build and renovation projects. The profile system made of durable thermal efficient uPVC is versatile and offers superior insulation.
Like all Thermotek products, it is a system that directly combats the costly thermally broken aluminium solutions in achieving the lowest u-values at the most economical cost for energy rating.
Achieve Affordable Passive House Design
At Thermotek, we know Passive Houses. Whether you’re designing a commercial or residential project, we can advise you on how to meet passive design standards while staying within budget. Investing in sustainable passive design now will not only save homeowners on bills in the long run; it will dramatically improve the impact on the planet.
Sustainability is at the forefront of our entire production process at Thermotek. We are a low-waste manufacturer, with all our products being 100% recyclable and manufactured in a sustainable way.
Contact our dedicated team today to find out more about using Thermotek window and door systems in a Passive House.