€10,000 sustainability investment raises energy label by average of 1.8 steps

In 2025, customers claimed an average of € 10,412 for energy‑saving measures. This is slightly higher than in 2024, when they submitted an average of € 9,880 in invoices. The measures claimed resulted in an improvement in the energy label. In 2025, customers improved by an average of 1.8 label steps, compared with 1.6 steps in 2024. This difference is due to a combination of higher investment and the choice of measures.

Insulation measures were particularly popular in 2025 among customers with a Verduurzamingshypotheek. The most frequently claimed items were energy‑efficient doors and window frames (25%), HR glazing (11.5%) and roof insulation (10.6%). 

Using funds from a Verduurzamingshypotheek, customers can pay for legally defined measures that directly contribute to lowering their energy bill. Solar panels continue to decline in popularity. In 2023, solar panels were still the number one choice with 32% of all claims. This share fell to 16% in 2024 and dropped further to 9% in 2025, now ranking only sixth.

According to Neriman Polat, manager Business Development Mortgages, the figures show that customers are choosing measures with long‑term returns: ‘Insulation is a good investment that often pays for itself within a few years. Insulation also has a significant impact on the energy label, more so than for instance solar panels. A better energy label provides customers with a lower energy bill as well as a higher property value. And of course, it benefits society, as a more sustainable home leads to structurally lower CO₂ emissions.’

The percentage of customers adding a Verduurzamingshypotheek when taking out a new mortgage decreased from 26.9% in 2024 to 21% in 2025. This is in line with the national downward trend. Earlier research from Advieskeuze.nl already showed that sustainability was discussed less frequently in consultations in 2025. Neriman Polat: ‘The percentage of new mortgages with a Verduurzamingshypotheek has also declined for us compared with previous years. But we also see that 9.2% of our customers added a Verduurzamingshypotheek afterwards by selecting the option in our interest offer. In its draft of the new mortgage‑advice guidelines, the AFM requests that sustainability be incorporated as standard and discussed more clearly during the consultation process. Now that our figures show that an investment of € 10,000 can improve a customer’s energy label by an average of 1.8 steps, this will hopefully provide additional motivation to address this topic.’ 

a.s.r. helps customers make their homes more energy‑efficient by offering a Verduurzamingshypotheek at a specially reduced interest rate and by informing customers about possible measures. The figures in this release are based on claims submitted by customers with a Verduurzamingshypotheek in 2025. The impact of the measures on the energy label was calculated by Calcasa based on claims and available source data.