Passive & High-Performance Homes
Windows for passive houses
Energy efficiency at its best
Passive Homes and high-performance homes are becoming increasingly important in Australia as homeowners, architects, and builders seek to reduce energy consumption, lower running costs, and create more comfortable living environments. With growing interest in sustainability and energy efficiency, the choice of windows and doors is critical: windows form a key part of the building’s thermal envelope, and selecting the right system is essential to maintain airtightness, minimise heat loss, and optimise energy performance.
aluplast uPVC systems are ideally suited to Passive Home applications. Our multi-chambered profiles provide excellent thermal insulation, superior airtightness, and long-lasting durability, helping homes maintain consistent indoor temperatures year-round. All aluplast systems can be used in high-performance applications, but our IDEAL 4000®, smart-slide, and lift-slide systems perform especially well. These systems combine energy efficiency with smooth operation, high security, and versatile design options.
Passive Homes - New Builds
Passive Homes in Australia are designed to minimise energy use and maintain comfortable indoor temperatures without relying on conventional heating or cooling systems. To generate warmth naturally, they often take advantage of solar gains, for example by incorporating large, energy-efficient windows on north-facing façades, while minimising window openings on the southern side. Proper window design is critical to achieving the thermal performance required for a Passive Home, including low heat transfer (U-values), high airtightness, and quality installation.
Passive Homes - Renovations and Existing Buildings
While fewer existing Australian homes are renovated to Passive House or ultra-low-energy standards, the trend is growing as energy efficiency and sustainability become key priorities. Upgrading older buildings often involves challenges such as narrow wall reveals, limited frame depth, or maintaining heritage façade aesthetics.
aluplast systems are well-suited to these projects, offering narrow-profile solutions and high thermal performance to improve energy efficiency without extensive structural modifications. Using high-performance windows from aluplast in renovations ensures improved comfort, lower energy bills, and compliance with Passive House principles, even in buildings not originally designed for high-efficiency standards.
Window Performance and Certification
Windows play a central role in a Passive Home’s thermal envelope. In addition to high-quality glazing, low U-values and airtight frames, attention to installation quality is critical to maintain the building’s energy performance. Australian Passive House projects typically aim for whole-window U-values around ≤1.0 W/m²K, depending on climate and orientation, while frame-only values are optimised to minimise thermal bridging.
By selecting aluplast uPVC systems, including IDEAL 4000®, smart-slide, and lift-slide, homeowners and builders can ensure their Passive Home or high-performance building meets stringent energy efficiency goals, while also providing durable, low-maintenance, and visually flexible solutions. Proper ventilation design is also key, with controlled systems ensuring fresh air circulation without compromising the thermal envelope or airtightness.
Terminology for passive houses
New buildings
Passive houses are buildings that are not equipped with any conventional heating systems. To generate warmth, passive houses often use energy from the sun's rays, for example by fitting large windows along the southern facade. They tend not to have any windows on the north-facing side or, if they do, the windows tend to be very small as very few solar gains are available. A range of specifications relating to window design apply to passive houses. For example, KfW requires a maximum Uw-value of 0.8 W/m²K to be eligible for funding while the privately-run Passive House Institute by Dr. Feist defines additional requirements for individual components, which often increase the price of these elements. The ift (the German Institute for Window Technology) has also published a new policy for passive-house windows, which is more or less the average of the two standards described above. For window fabricators, it is important to note which variant is required, as the requirements in the tender information must be fulfilled regardless of other alternatives.
Old buildings
Relatively speaking, not many old buildings are renovated to passive house standard at the moment, though the German government are hoping that this will become standard over the medium to long-term. In the window industry, aluplast is the only system provider to offer a narrow construction depth of just 70 mm, which is certified according to the ift (German Institute for Window Technology) passive house standard.
Passive house certificate as per Dr. Feist
The most famous passive house expert is the head of the Darmstadt-based Passivhaus Institut, Dr Wolfgang Feist. The Passivhaus-Institut PHI uses a set of stringent criteria to certify structural components: the heat transmission coefficient for windows must not exceed Uw ≤ 0.80 W/m²K in total. The frame alone must reach the same level of Uf ≤ 0.80 W/m²K. The window is also assessed in its mounted state, where the threshold amounts to Uw installed ≤ 0.85 W/m²K.
KfW requirements
KfW (a German bank that specialises in development) promotes the installation of energy-efficient windows. Depending on the energy efficiency of the building as a whole, the bank distinguishes between various classes of Efficiency Houses, which are eligible for different levels of funding. The Efficiency House class with the strictest requirements (KfW 40) applies only to new buildings. To be eligible, the window must achieve a total U-value of 0.8 W/m²K.