Setting a New Benchmark for Better Homes

At ECOWINDOWS, we believe it’s time to challenge outdated expectations in the building industry. New Zealanders deserve homes that are warmer, healthier, and more energy efficient, and that starts with choosing building components that deliver outstanding performance.

High-quality and carefully manufactured European windows and doors achieve the best energetic results for your home. These products are made with decades of experience in energy-efficient building in Europe where for a long time, high-quality windows are most commonly used.

Germany vs. New Zealand: A Tale of Two Standards

As a world leader in manufacturing high-performance windows, Germany has a long history of stringent and rigorous government regulations, the so-called EnEV law. This law outlines the requirements for newly built and existing homes’ energy efficiency. The principles focus on the high quality of insulation and low heat loss rates to ensure houses are kept warm and cosy, without generating hefty power bills.

In contrast, New Zealand’s Building Code takes a more general, performance-based approach. [1] The Code describes performance criteria and sets the standards for moisture control, energy efficiency features, and others for all sorts of buildings, from residential to commercial and industrial constructions [2]. It defines how a building must perform in its general use rather than describing how it must be designed and constructed. [3]

The Numbers Tell the Story

Looking at the numbers, it becomes evident that the German law requirements are much stricter than those of the New Zealand building standard.

The effectiveness of windows is usually calculated internationally as U-value. However, in New Zealand, the R-value is still widely used. In contrast to the desired high R-value, a lower U-value indicates better performance and insulation. The R-value is the reciprocal of the U value and vice versa (R = 1/U and U = 1/R).

The German EnEV law regulates the required U-value rates for each area of a house, including the windows, which play a crucial role in energy-efficient building. Hence, it is only allowed to install double-glazed windows with a low U-value of 1.30 in German houses. This rate is a minimum requirement. Triple-glazing can enhance performance even further.

Compare that with New Zealand’s Building standard: the BRANZ House Insulation Guide specifies the R-value for a high-performance window in wood or PVC with R 0.48. [4] To compare this value with the German requirements, we have to convert the R-value of 0.48 into the U-value, using the appropriate formula U = 1/0.48. The result is a U-value of 2.08.

This means that the minimum requirement for a German window (U 1.30) exceeds the value for a high-performance window in New Zealand (U 2.08) by far. Remember: a low U-value indicates better performance and is therefore desired.

That’s a significant gap. In other words, what’s considered “high performance” in New Zealand still falls far short of minimum standards in Germany.

 

Building Better With ECOWINDOWS

We believe that it is vital to utilise windows that match the German market’s high standards and strict requirements. This approach allows us to build dry, warm and healthy homes for everyone here in New Zealand. However, double- and triple-glazing of windows is only one part of a comprehensive heat-management system. Other measures include the installation of modern ventilation and shading systems.

Ready to Raise the Standard for Your Home?

No matter your requirements, ECOWINDOWS offers wholly customised solutions for new builds and renovations alike. Get in touch with our team today, we’d love to help bring your project to life.