ROTTERDAM, 4 February 2025 – Homeowners in South Holland received substantial subsidies for sustainability improvements in 2024, though Rotterdam residents saw less benefit due to high numbers of rental properties. In 2025, the rules and subsidy amounts have changed, affecting homeowners considering renovations this year.
ISDE subsidies mostly granted outside Rotterdam
Since 2016, the Investeringssubsidie duurzame energie en energiebesparing (ISDE) has provided financial support to homeowners investing in energy-efficient upgrades. New research by the sustainability platform Slimster, based on data from the Regional Climate Monitor, shows that in 2024, subsidies were primarily allocated in smaller municipalities outside major cities.
In South Holland, Wassenaar received the highest subsidies per household, with an average of nearly €3,700 per 100 households. Other municipalities high on the list include Nieuwkoop, Bodegraven-Reeuwijk, Midden-Delfland, and Voorschoten. Residents of Voorschoten most frequently applied for insulation subsidies, while those in Bodegraven-Reeuwijk and Nieuwkoop led in applications for heat pumps. The typical subsidy per application was approximately €2,700.
Rotterdam sees fewer subsidies due to housing composition
Rotterdam, along with cities such as Delft, Leiden, and The Hague, saw lower ISDE allocations. According to Marco Schuurman of Slimster, this is largely due to the housing composition in urban areas.
“The ISDE subsidy is specifically for homeowners, and cities like Rotterdam have a high proportion of rental properties and apartments,” Schuurman explained. “Additionally, homes outside the city are often larger and detached, which means more insulation material and larger heat pumps are needed. These higher costs lead to higher subsidies.”
Changes in ISDE subsidies for 2025
Homeowners planning renovations in 2025 should be aware of changes in subsidy amounts. The subsidy for triple glazing has increased significantly, from €65.50 to €111 per square metre, while support for HR++ glass remains at only €25 per square metre. Triple glazing is only eligible for a subsidy if installed with insulating window frames, typically made of synthetic materials.
Additionally, the government aims to encourage the use of sustainable insulation materials. Homeowners choosing biobased materials such as wood fibre or sheep wool can receive a bonus subsidy of up to €6 per square metre, depending on the type of insulation.
Conversely, subsidies for heat pumps have been adjusted. The minimum subsidy has been reduced from €2,100 to €1,250, but for larger systems, the subsidy per extra kW has increased from €150 to €225. This change is intended to promote heat pumps with higher efficiency or greater capacity, particularly for larger homes.
Conclusion
While Rotterdam residents benefited less from ISDE subsidies in 2024 due to housing composition, changes in 2025 could affect future applications. Homeowners looking to invest in sustainability measures should consider the updated subsidy conditions to maximise their benefits.
