The Ultimate Guide to Passive Windows For Builders

Energy Efficiency is now being realised as the main factor in Australian residential design as new homes move away from the dependence on natural gas for heating and cooking and shifting to an all-electric home.  With this shift comes added demand on our electricity grid and additional solar generation input – so the performance of our new homes and appliance selection must be carefully considered early in the design phase to maximise energy efficiency and minimise our daily running energy consumption and carbon footprint.  

Heating and cooling our home is by far the biggest consumption of energy for households.

So how do we design a home to maintain a comfortable, ambient temperature for all year-round while minimising the use of appliances for temperature regulation?

Passive Design. 

Originally established in Germany, Passive Houses emerged in the 1990s and have become a global standard for high performance building. The Australian Passivhaus Association says the data shows that Passive Houses use 80-90% less energy than traditional builds. 

Certified Passive House designs adopt a “fabric-first” approach, using high-quality materials and thoughtful design elements. One of the key elements in this selection is high performance windows and doors. 

How Does Windows and Door Selection Effect Energy Efficiency?

Key principles of passive design include thermal insulation, thermal bridge elimination, air tightness, Heat Recovery Ventilation (HRV) Systems and of course, high-performance windows and doors.  All of these principles combined will achieve the comfortable living environment with minimal use of heating and cooling appliances to control the air temperature.

High-Performance window systems, such as those designed and manufactured by Thermotek, play an essential role in achieving the required air-tightness requirements for Passive Certification and eliminating thermal bridging and condensation.  

Thermotek combines advanced German engineering with local, tailored Australian manufacturing to deliver windows and doors that are not only environmentally sustainable, but provide exceptional thermal performance in our unique Australian climate.

Our products are made with top-quality Aluplast uPVC profiles; crafted to meet the highest standards in sustainability and performance.

Thermotek’s range of uPVC windows, such as the Boutique Series and Smart Slide systems, is built to maximise energy efficiency through superior insulation, airtight seals, and optimised solar control. In doing so, they reduce reliance on heating and cooling systems.

What Exactly is uPVC and How is it Energy Efficient?

uPVC, or unplasticised polyvinyl chloride, is a durable and sustainable material. Unlike traditional PVC, it is crafted without chemical plasticisers. Instead, it incorporates impact modifiers and fillers to create a strong, adaptable structure. During manufacturing, long polymer chains intertwine, creating a tough material reinforced with additional impact modifiers.

An added benefit of uPVC is its ability to become even stronger through recycling, gaining durability with each cycle. This characteristic makes uPVC a great material for passive house construction, where both sustainability and long-term durability are considered. It is also a non-conductive material, meaning that it enables energy efficiency by preventing heat transfer.

How do Thermotek Windows Enhance Passive Design for Builders?

Superior Energy Efficiency

Thermotek windows enhance passive design in a multi-faceted way. As our uPVC window frames are non-conductive, they prevent heat transfer and shield interiors from outdoor temperatures. Paired with double or triple glazing, these frames can substantially reduce or even eliminate the need for heating and cooling systems.

All of our window systems also come with either double or triple glazed windowpanes. This provides superior insulation, which contributes to energy efficiency, thermal comfort, and noise reduction in a building.

These windows consist of two or three layers of glass separated by insulating gaps filled with air or inert gas, which slows down the transfer of heat. This helps retain warmth during colder months and limits heat entry during warmer months, reducing the need for heating and cooling systems. 

By minimising heat loss and gain, double and triple glazing windows lessen the workload on heating and cooling control systems, significantly lowering energy consumption and utility bills, a huge advantage in an era of climate volatility. 

The improved insulation creates a more stable indoor temperature, reducing the chances of cold drafts or overly warm areas near windows, making the environment comfortable year-round. The additional glass layers and insulated gaps also act as sound barriers, reducing external noise—a valuable benefit for homes in busy or urban areas.

Double and triple glazing help control condensation on window surfaces, reducing moisture build-up and minimising the risk of mould, which can impact indoor air quality and structural integrity over time. By incorporating double or triple glazed windows, passive design not only achieves better energy efficiency but also fosters a healthier, quieter, and more comfortable living space.

Thermotek windows, such as our Boutique Series, are also equipped with insulated glass units (IGUs) that include Low-E coatings and argon gas to boost thermal performance.

The advanced sealing systems used across all Thermotek products ensure airtight protection, further supporting passive design and enhancing long-term energy efficiency and durability.

How are Thermotek uPVC Windows & Doors Sustainable?

Embodied energy covers the total energy used throughout a material’s lifecycle—from extraction and manufacturing to transportation and installation, maintenance and disposal or recycling.

uPVC, especially recycled uPVC, has lower embodied energy than aluminium and steel. It is highly durable and requires minimal maintenance, which lowers the energy demand over its lifecycle.

Advances in uPVC production have also made it more energy-efficient, with recycling options reducing the overall energy impact.

Thermotek’s uPVC products, including our Smart Slide and tilt-and-turn systems, are fully recyclable, low-maintenance, and highly durable. Our manufacturing process in our sustainable facility in Melbourne minimises waste, ensuring an efficient use of resources and reducing environmental impact.

Exceptional Durability for Building Projects

Durability is a major advantage of uPVC, ensuring window profiles remain resilient against environmental factors without compromising performance. Thermotek uPVC windows and doors are resistant to salinity, moisture, fungi, and rust. This eliminates the need for expensive, on-going maintenance.

All Thermotek products are engineered to resist chemical erosion, preventing moisture build-up and mould growth, even in humid or coastal conditions. This durability makes our window systems a smart investment for passive design.

Engineered for Australian Passive Houses

Thermotek’s windows and doors are built for Australia’s diverse and sometimes extreme weather conditions. Our uPVC frames are capable of withstanding temperatures up to 400°C and comply with BAL-40 (Bushfire Attack Level) standards, making them suitable for fire-prone areas.

Thermotek products are also rigorously tested for wind resistance, enduring wind speeds up to 200 km/h, which makes them ideal for coastal and high-wind regions. Whether in Australian suburban homes or coastal buildings, Thermotek windows provide builders with the reassurance of high performance and safety.