Overview

• In municipalities over 100,000 residents, completed heat plans by June 30, 2026 will bar installers from fitting new boilers that run solely on fossil gas.
• Named cities include Frankfurt, Wiesbaden, Kassel and Darmstadt in Hesse, and in Lower Saxony Hannover, Braunschweig, Oldenburg, Osnabrück, Wolfsburg, Göttingen, Salzgitter and Hildesheim.
• Most smaller municipalities generally have until June 30, 2028, though earlier plan adoption triggers the restriction sooner.
• Existing oil and gas systems may keep operating and be repaired, with a full fossil phase-out set for 2045; replacement systems face rising renewable shares of 15% in 2029, 30% in 2035, 60% in 2040 and 100% in 2045.
• In multi-family buildings, owners’ associations can take up to five years to decide and eight more to implement a solution after a failure, with federal subsidies available and rising CO₂ costs expected to make fossil heating pricier.