The Netherlands Authority for Consumers and Markets (ACM) has published a roadmap that outlines the key milestones in its preparations for the Dutch Collective Heat Act (Wet collectieve warmte, or Wcw). This new legislation will replace the existing Dutch Heat Act (Warmtewet) and is expected to come into effect on January 1, 2027.

ACM's role under the new law includes ensuring that heat companies do not earn excessive financial returns from heat supply. Each year, ACM will set maximum prices for heat and ensure that companies provide reasonable conditions and maintain the capability to supply heat reliably to households. The roadmap provides insights for heat companies, consumer organizations, and other stakeholders regarding the timeline and opportunities for input.

ACM is preparing for several regulatory changes, including cost-based tariff regulation and the establishment of new regulatory accounting rules (RAR). These changes will help ensure that heat companies submit accurate financial data that can be compared effectively. Additionally, ACM is developing a method for determining the standardized asset value (GAW) of heat networks, which will be crucial for calculating cost-based tariffs.

One significant change under the Dutch Collective Heat Act is the shift from the current 'no-more-than-otherwise' principle (NMDA) to tariffs based on actual costs. This transition will occur in three phases, starting with adjustments linked to the natural gas price when the Act comes into effect. The second phase will involve setting tariffs for large collective systems based on efficient costs, while the third phase will focus on allowed revenues for specific heat networks.

ACM will engage with stakeholders through consultations and sounding-board groups leading up to the Act's implementation. Key meetings are scheduled for heat companies and municipalities, with consultations on new regulatory rules beginning in 2026. Stakeholders can access the timeline and provide input through ACM's website.