Germany implements phased solar and energy mandates for new buildings

Germany is implementing a phased transition to new building energy standards to comply with the revised EU Building Directive. The Building Modernization Act (GModG), formerly the Building Energy Act, was published in the Federal Law Gazette on July 28, 2026, and has been in effect since July 29, 2026.

The transition follows a multi-stage timeline:

• From January 1, 2027: The previous 55 percent factor will be replaced by an energetic standard calculated via a new reference building model (DIN/TS 18599:2025-10). Additionally, new public non-residential buildings and other new non-residential buildings with more than 250 square meters of usable area will require solar installations.

• From January 1, 2028: New public non-residential buildings must be constructed as zero-emission buildings. For new constructions exceeding 1,000 square meters, life-cycle greenhouse gas emissions must also be determined.

• From January 1, 2030: The zero-emission standard will apply to all new constructions, and the solar mandate will extend to new residential buildings.

While individual German states previously had varying solar mandates, this national framework aims to harmonize requirements. The mandate typically applies to new constructions or fundamental roof renovations rather than existing intact roofs, often allowing for solar thermal systems as an alternative.