In 2021, the government announced changes to the Building Code to increase the energy efficiency of buildings. This update includes increased minimum R-values for residential and small buildings.

The requirements will be introduced over the next two years and will vary across six new climate zones.

Image source: Building Code Update 2021 – page 13

New Minimum R-values for Windows in Residential Buildings

Among other elements, windows will also need to improve their performance to retain more heat indoors.

By the end of 2023, all regions must meet a minimum R-value of R0.46 (zones 1–4), while homes in zones 5–6 must achieve at least R0.50.

Raising window insulation standards is a necessary step, given that windows are typically the largest point of heat loss in a home.

These performance targets do not prescribe a specific window type, offering flexibility in meeting the standard. Although not mandatory, solutions like Low-E (low-emissivity) glass and thermally broken frames are expected to become more widely adopted.

Image source: Building Code Update 2021 – page 15

Comparison with the German Standard

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 to ensure high-quality insulation and low heat loss rates.

The German EnEV law regulates the required U-value rates for each housing area, including the windows. Hence, it is only allowed to install double-glazed windows with a low U-value of 1.30 in German houses. This value equals an R-value of R0.77 compared to New Zealand’s R0.46 and R0.50 as a minimum requirement.

Still Outperforming the Code

Increasing the insulation of New Zealand houses will help to improve current construction weaknesses. However, the announced changes could go much further.

All our products are manufactured in Germany and Europe. Their performance is oriented on the high standards and long history of energy-efficient building in these markets. Low-E glass (low emissivity glass) and argon filling are already standardly included in every window system of ECOWINDOWS’ product range. This enhancement significantly improves the performance of our windows compared to other window types.

Our heat protecting double-glazed window systems achieve R-values starting at R0.91, which already outperforms the required values of R0.46 and R0.50 of the new Building Code by far.

ECOWINDOWS standard triple-glazing offers values as low as R2. This performance can get even further enhanced depending on the selected window system.

High-Performance Building Solutions

We believe in using windows that align with the highest international standards, such as those enforced in Germany. This ensures homes in New Zealand can be dry, warm, and healthy year-round.

ECOWINDOWS’ carefully crafted German and European windows deliver exceptional energy efficiency, which is the result of decades of expertise in sustainable building in Europe, where high-quality windows are commonly used for a long time.

Whatever your needs, ECOWINDOWS offers custom solutions for both new builds and renovations.

Contact us today to learn more about our products and services.