Germany's Building Modernisation Law Faces Constitutional and Technical Criticism

The Bundestag’s scientific service warns that the Building Modernisation Act (GModG), set to replace the current heating law, may breach Germany’s constitution and EU climate rules. Experts say the draft could increase greenhouse‑gas emissions and is unlikely to survive a challenge before the Federal Constitutional Court. The law, a key promise of the governing coalition, also permits limited use of fossil‑gas boilers until 2040, sparking further legal doubts.

Critics point to several technical shortcomings. The proposal keeps an outdated surface‑area metric for solar‑thermal collectors, disadvantaging more efficient German and European modules, and relies on costly bio‑fuels whose availability is uncertain. Provisions for wood heating and heat‑pump performance remain vague, while the “bio‑fuel ladder” targets for renewable gases are seen as insufficient and economically burdensome for landlords and tenants alike.