Replacing low-performance windows with modern energy-efficient ones can significantly reduce heat loss. This is the conclusion of a study (pdf)↗️ by the Fraunhofer Institute for Building Physics IBP, commissioned by the European window industry.
Based on the study, European window associations European Aluminium, EuroWindoor, and EPPA launched a social media campaign highlighting the role of windows in achieving the EU’s climate targets. The campaign urges EU and national policymakers to support investments in energy-efficient windows to enhance energy efficiency and combat climate change.
Buildings account for 43% of final energy consumption in the EU, primarily for heating. Reducing heating costs is therefore critical for meeting the goals of the European Green Deal. On average, modern windows save up to 15% of heating energy.
According to the authors, replacing 1% of windows annually over ten years with modern windows featuring a U-value of 0.9 to 1.3 W/m²K could result in a 3.5% energy saving in Central Europe. This saving potential varies by climatic region and typical local U-values in individual EU member states. The highest savings potential is in the Baltic countries (4.5%) and the lowest in southern countries (2.1%).
OKNA.ua reminds that in Ukraine, energy efficiency requirements for windows were tightened on September 1, 2022, in accordance with DBN B.2.6-31:2021:
Residential and public buildings: 1.1 W/m²K for Zone I and 1.3 W/m²K for Zone II (Zakarpattia, Zaporizhzhia, Mykolaiv, Odesa, Kherson regions, and Crimea).
Window selection should consider not only thermal properties but also the solar factor to balance heat and lighting needs.
Simulation studies indicate that replacing existing EU building stock windows with those having a Uw value of 1.3 W/m²K and a solar factor (g) of 0.60 achieves similar energy savings as replacement with windows featuring a Uw of 1.1 W/m²K and a g value of 0.54.
Researchers also note that replacing old windows can significantly enhance thermal comfort, reduce localized discomfort like drafts, and improve sound insulation.
As previously reported by OKNA.ua, international demand for windows and doors in Germany remains under pressure due to economic uncertainty. However, special programs are expected to provide the necessary incentives for private investment in replacing glazing structures.