No. The Heating Plan does not immediately require you to take action. Existing, functioning heating systems may continue to be operated. As of July 29, 2026, the Building Modernization Act (GModG) will govern the requirements for newly installed heating systems.

The previous general requirement that a new heating system must use at least 65 percent renewable energy has been eliminated. The GModG is designed to be more technology-neutral. For example, heat pumps, district heating connections, biomass and hybrid heating systems, as well as gas, oil, and propane heating systems, may continue to be used. However, fossil fuel-based heating systems are subject to gradually increasing requirements regarding climate-friendly fuels.

In the Mainz-Lerchenberg area, mandatory connection to the district heating network has been in effect since 1984. Whether mandatory connection to an expanded or new district heating network will be introduced in the future depends on various factors. The Municipal Heating Plan itself does not constitute grounds for a mandatory connection or usage requirement. Whether such a requirement will be introduced in other areas is a separate legal issue and would require a distinct legal basis or decision.

Yes, existing heating systems may generally continue to be used. If a new heating system is installed, the requirements of the Building Modernization Act (GModG) will apply as of July 29, 2026. The previous general 65-percent requirement has been eliminated.

Under certain conditions, the GModG permits various heating technologies. In principle, gas, heating oil, and propane heating systems may continue to be installed. However, for systems newly installed after July 29, 2026, requirements regarding the proportion of certain climate-friendly fuels will gradually increase starting in 2029. For new gas, heating oil, and liquefied petroleum gas heating systems, the following minimum proportions of climate-friendly fuels generally apply: 10 percent starting in 2029, 15 percent starting in 2030, 30 percent starting in 2035, and 60 percent starting in 2040.

The Heating Plan is not a personalized guide, but it does help you assess your own situation: First, check which type of heating supply is shown for your area (district heating network or decentralized solution). Keep in mind that the plan provides long-term guidance through 2035 or 20240—specific timelines for the actual expansion of district heating networks will be developed in subsequent phases.

The fact that an area is designated as a potential district heating area does not therefore automatically mean that a connection will be available at a specific point in time. If you’re planning to replace your heating system or renovate your home, it’s worth looking into current incentive programs and seeking independent energy counseling, e.g., through the Consumer Advice Center: