IN Brief:
- The Bundestag has approved the Building Modernisation Act in place of the Building Energy Act.
- The general requirement for new heating systems to use 65% renewable energy will be removed.
- Fossil-fuel systems remain permitted but face increasing renewable-fuel blending requirements from 2029.
The German Bundestag has approved legislation replacing the country’s Building Energy Act with a Building Modernisation Act that removes the general requirement for newly installed heating systems to use at least 65% renewable energy.
Owners will receive greater choice over the heating technologies installed in new and existing buildings. Gas and oil systems will remain available, although the fuels used in them will become subject to progressively stronger climate requirements.
Under the approved provisions, newly installed gas and oil systems in existing buildings must use a minimum proportion of lower-carbon fuel from 2029. The requirement begins at 10%, rises to 15% in 2030, 30% in 2035, and 60% in 2040, before heating fuels are expected to become climate-neutral by 2045.
The legislation must now complete the remaining federal process. Although the Bundesrat cannot veto it in the same manner as legislation requiring full state consent, it can seek mediation and further consideration before enactment.
Germany’s previous 65% rule placed renewable heat, district heating, heat pumps, biomass, and qualifying hybrid systems at the centre of replacement decisions. The revised framework transfers more immediate choice to building owners while using fuel requirements and the 2045 climate-neutrality target to shape the longer transition.
European building policy continues to influence the national framework, including requirements connected with zero-emission new buildings and the decarbonisation of existing stock. Municipal heat planning, energy-performance standards, public funding, and the EU Energy Performance of Buildings Directive will all continue to shape individual projects.
For contractors and building-services designers, a broader range of lawful systems does not necessarily simplify long-term specification. Heating equipment installed now may remain operational for two decades or more, placing fuel availability, carbon pricing, network development, and future compliance within the whole-life calculation.
Gas or oil equipment may carry a lower initial cost where existing distribution systems, emitters, and plant spaces can be retained. Rising renewable-fuel requirements could, however, expose owners to future prices and supply conditions that remain difficult to estimate at the point of installation.
Heat-pump projects require a different set of technical assessments. Fabric performance, electrical capacity, flow temperatures, emitter sizes, controls, noise, hot-water demand, and external-unit location all influence efficiency and reliability.
Removing a general percentage rule leaves those considerations unchanged where electrification remains the preferred option. Poorly matched equipment can increase energy use and operating costs regardless of whether the technology satisfies a legal threshold.
District-heating decisions will continue to depend on local network development. Municipal heat planning is intended to give owners clearer information about where strategic heat systems are likely to become available, but construction and connection dates will vary between regions.
The transition could create uneven demand across the installation and manufacturing market. Some owners may proceed with conventional replacements, while others continue with heat pumps, hybrid systems, or connection-ready designs because of energy costs, available incentives, or corporate carbon targets.
Manufacturers must manage that uncertainty through product development, distribution, installer training, spares, controls, refrigerants, combustion equipment, and digital monitoring. Investment decisions become harder when the preferred technology mix can shift with fuel prices and public policy.
The revised law has attracted sharply different responses. Supporters argue that greater technology choice and phased fuel requirements will reduce disruption and allow systems to be matched more closely to individual buildings.
Critics contend that continued installation of fossil-fuel equipment could leave owners exposed to higher future costs and slow progress towards building-sector emissions targets. Much of that debate will ultimately be tested through whole-life expenditure rather than the legal status of one technology.
Designers will therefore need to set out capital cost, likely energy consumption, fuel exposure, maintenance, expected equipment life, and the consequences of later conversion in a form clients can compare. A low-cost replacement may become more expensive if fuel or compliance requirements change during its operating life.
Documentation will remain important throughout that period. Owners need records of installed systems, commissioning, energy performance, fuel compatibility, and future upgrade requirements, particularly where equipment is expected to operate with progressively higher renewable-fuel blends.
The Bundestag vote changes the immediate direction of German heating policy without ending the decarbonisation of buildings. It replaces a broad technology threshold with a gradual combination of owner choice, fuel transition, energy standards, and the national 2045 climate-neutrality objective.
