Updated: May 2026 — the key facts in 60 seconds

The GEG (Gebäudeenergiegesetz — German Building Energy Act, also known as 'Heizungsgesetz' or 'Heating Act') has, since 2020, regulated the energy requirements for residential and non-residential buildings, consolidating EnEV, EnEG and EEWärmeG. The widely discussed 65% renewable energy requirement for new heating systems has been in force since 01.01.2024 for new buildings in newly designated development areas. For existing buildings it phases in together with municipal heat planning — in large cities from mid-2026, in smaller municipalities from mid-2028. Until then: existing heating systems may continue to operate, new gas heating systems are conditionally permitted — with mandatory advisory. We recommend that owners in Munich and Upper Bavaria approach a heating replacement strategically rather than out of panic.

What is the GEG (Gebäudeenergiegesetz)?

The GEG (Gebäudeenergiegesetz) has been, since November 2020, the central federal law for energy requirements on buildings in Germany. At that time it replaced three predecessor regulations:

the Energy Saving Ordinance (EnEV),
the Energy Saving Act (EnEG),
the Renewable Energies Heat Act (EEWärmeG).

The GEG regulates, among other things: minimum standards for new builds, requirements during renovation, obligations on a change of ownership, the energy certificate obligation, heating system replacement and sanctions for violations. The GEG amendment of 2024 brought the reform colloquially called 'Heizungsgesetz' — with a focus on heating and the 65% renewable rule for new heating installations.

In public debate, GEG is often reduced to heating topics. In fact, the law covers the entire energy lifecycle of a building — from the envelope quality through plant technology to obligations on sale and rental.

The 65% renewable energy requirement — who is affected, who is not?

The most frequent question in 2025/2026 consultations: 'Do I now have to replace my heating?' The short answer: in the vast majority of cases, no — at least not immediately.

New build in newly designated development areas: Here the 65% renewable energy requirement has applied since 01.01.2024 without a transitional period. Anyone building in a designated new development area must design the new heating system so that at least 65% of the heat supplied comes from renewable energies.

Existing buildings and new builds outside designated development areas: Here the 65% requirement only applies once the respective municipality has presented its heat planning. For large cities (over 100,000 inhabitants), municipal heat planning is required by 30 June 2026 at the latest; for smaller municipalities by 30 June 2028 at the latest. Only then does the renewable obligation apply to owners who install a new heating system from that cutoff date onwards.

Existing heating systems may continue to operate. Anyone with a functioning gas or oil heating system is not forced to replace it — regardless of the GEG. A replacement obligation only exists for very old constant-temperature heating boilers (see below) or in the case of a defect in combination with municipal heat planning.

Local note: The City of Munich has its municipal heat planning in draft in 2026 — adoption is expected in the course of the year. In the district of Starnberg, in Tölzer Land and in the 5-Seen-Land, planning is progressing at different paces in the individual municipalities. Until formal adoption: existing systems may continue to operate, new heating systems are possible — but we recommend strategic preparation via a [renovation roadmap](/sanierungsfahrplan). (As of May 2026, subject to local implementation.)

Which heating technologies fulfil the 65% rule?

The GEG names several technologies that are deemed 65%-renewable-compliant:

Heat pump (air-water, geothermal, water-water). Air-water, brine-water (geothermal) or water-water heat pump. Heat pumps are currently the most common variant in existing buildings. More on this in the article on the [heat pump in existing buildings](/ratgeber/waermepumpe-altbau-bayern).

Connection to a district heating network. If the municipality or an energy supplier operates a long-distance or local heating network that meets the GEG requirements, connection is a coherent solution. In Munich, the district heating network is being expanded in several districts — Sendling, Schwabing-West, Bogenhausen in parts. (Availability of an actual connection depends on local planning and is not guaranteed.)

Direct electric heating. Such as infrared or heat-storage heating — permitted in buildings with very good efficiency-house standards, otherwise only of limited use.

Solar thermal as hybrid. Solar thermal systems can be part of the 65% renewable solution, in combination with another heat source.

Biomass. Wood pellets, wood chips, split logs. Recognised, with requirements on efficiency and emissions. In rural areas (Tölzer Land, Pfaffenwinkel) experience suggests these remain attractive.

H2-ready gas heating. A hydrogen-capable gas heater in combination with a municipal hydrogen supply commitment for green hydrogen. In practice currently rarely a real option in southern Bavaria.

Hybrid: gas + heat pump. Heat pump plus existing gas boiler for peak load coverage — a transitional technology that often makes sense in existing-building renovations.

What does NOT fulfil the 65% rule: A purely new gas or oil heating system without a renewable share is no longer permitted once municipal heat planning takes effect. Until then: installation possible, but with mandatory advisory on the consequences.

Replacement obligations on a change of ownership

Anyone who inherits or buys a residential building may take on obligations that the previous owner did not fulfil. Within two years after the transfer of ownership, the following measures must be implemented, if not already done:

1. Replacement of old heating boilers. Constant-temperature heating boilers older than 30 years must be replaced. Low-temperature and condensing boilers are exempt. This obligation has existed since the EnEV and was transferred into the GEG.

2. Insulation of the top-floor ceiling (oberste Geschossdecke). If the top-floor ceiling (or the unconverted roof above it) does not meet the minimum U-value of 0.24 W/(m²K), insulation is mandatory.

3. Insulation of hot-water and heating pipes in unheated rooms.

Anyone buying an existing property should check these obligations before signing the contract. At enbe we offer a [pre-purchase advisory](/vor-kauf-beratung) for this — a well-founded assessment of the energy condition and the medium- to long-term investment needs.

Energy requirements during renovation

The GEG also sets minimum standards as soon as more than 10% of a building component is altered during a renovation. In other words: anyone removing the render from the façade anyway must meet the prescribed U-value on subsequent reinstatement.

Typical thresholds: - External wall on insulation: U ≤ 0.24 W/(m²K) - Roof on renovation: U ≤ 0.20 W/(m²K) - Window replacement: U ≤ 1.3 W/(m²K) for windows - Top-floor ceiling (oberste Geschossdecke): U ≤ 0.24 W/(m²K)

Mandatory energy certificate: A valid energy certificate must be available on sale, rental and lease and presented unsolicited to potential interested parties. More on this in the article [demand or consumption certificate?](/ratgeber/energieausweis-bedarf-verbrauch).

Local note: The GEG applies uniformly throughout Germany. But in practice the Munich district office (Landratsamt), the City of Munich and some municipalities in water protection zones (e.g. around Lake Starnberg, at Lake Ammer) often impose additional requirements — for example for listed buildings (heritage) or ensemble protection, or for renovations in water protection zones.

Risk of fines and sanctions

Violations of the GEG are administrative offences. Fines are provided for in the GEG, the specific amount depends on the individual case, severity of the breach and degree of fault.

Typical scenarios: - Missing energy certificate on sale or rental. Here fines into the five-figure range are possible. - Breach of the replacement obligation (e.g. a constant-temperature boiler >30 years not replaced). Subsequent demand by the building authority; refusal may result in fines. - Incorrect statements in property listings (e.g. missing mandatory details on the energy certificate). Additional competition-law risks on top of the administrative-offence law.

Important: actual enforcement intensity varies regionally. In Bavaria, GEG violations are increasingly being monitored, particularly in the sale and rental context.

Municipal heat planning — what affects Munich and Upper Bavaria

Municipal heat planning is the central lever from which the 65% renewable requirement takes effect in existing buildings. It shows, for each street or neighbourhood, which heat supply is envisaged in future: district heating network connection, decentralised heat pump or hydrogen option.

City of Munich: Municipal heat planning is in draft preparation. It is expected that for parts of the city area, connection to the municipal district heating network will be envisaged — particularly close to the city centre and in several districts. Anyone living in such areas should check the expected connection option before investing in a new heating system. (As of May 2026, subject to local implementation; availability of a connection is not guaranteed.)

Augsburg: Its own heat planning is under way. Here too the city will initially rely on a mix of district heating expansion and heat pump strategies.

5-Seen-Land and Upper Bavarian rural districts: Municipalities are at different stages. Some small municipalities have already submitted concepts, others only begin in 2026. The obligation applies in these municipalities by mid-2028 at the latest.

We clarify specific district heating network connection options for your property in the initial consultation — we have an overview of regional planning statuses and can advise you on an informed basis.

What owners should do NOW

Four strategic levers that make sense regardless of scaremongering and political debate:

1. Have an individual renovation roadmap drawn up. The [iSFP](/sanierungsfahrplan) offers a structured roadmap for 10–15 years. It is the strategic bracket for all further measures and is itself eligible for funding. In addition, it unlocks the iSFP bonus on later individual measures from BEG EM.

2. Plan the heating replacement strategically, not out of panic. The funding rate for efficient heating systems from BEG EM is currently high — but experience suggests this changes over the years. Anyone timing the replacement cleverly (e.g. when the existing heating system is heading towards the end of its life anyway in the next 3–5 years due to age) often achieves an economically sensible solution.

3. When buying a house: check GEG obligations in advance. Taking over a property can entail renovation obligations within two years. Clarify in advance via the [pre-purchase advisory](/vor-kauf-beratung) — this avoids later surprises.

4. Use local funding levers. FKG of the City of Munich, municipal programmes in individual rural districts, programmes of the Bavarian state funding. Our [funding strategy](/foerderberatung) checks which combinations actually take effect for your property.

Quick FAQ

Do I have to replace my gas or oil heating immediately? No. Existing heating systems may, in principle, continue to operate. A replacement obligation only exists for very old constant-temperature heating boilers (>30 years, with exceptions for condensing and low-temperature boilers) and after certain deadlines expire in combination with municipal heat planning.

What happens if my heating breaks down? If the heating system fails irreparably (emergency), there are transitional periods. An emergency repair is possible; the final new system must be installed within a reasonable period and, from the entry into force of heat planning, must comply with the 65% renewable rule.

Am I exempt from the GEG if I own a listed building (heritage)? Listed buildings and buildings in a protected ensemble can be exempted from individual requirements if renovation would disproportionately impair the appearance or substance. This must be clarified in each individual case with the heritage authority — we are happy to coordinate this.

Do I get funding despite a GEG obligation? Yes, mandatory measures are also partially eligible for funding — in particular if they go beyond the statutory minimum or are implemented as part of an iSFP. We check funding possibilities individually on every project.

When does municipal heat planning take effect in Munich? The City of Munich has heat planning in draft; formal adoption is expected during the course of 2026. Only from that cutoff date does the 65% renewable rule apply to new heating systems in existing buildings. (As of May 2026, subject to local implementation.)

Do I need an energy certificate if I inherit? In the case of pure inheritance without sale, no energy certificate obligation arises. As soon as the inherited property is sold or rented, however, a valid [energy certificate](/energieausweis) is mandatory.

Next step

Want clarity on what the GEG concretely means for your property? In a free 20-minute initial consultation, we sort through obligations, deadlines and sensible measures. [Arrange an appointment](/kontakt) or call 089 / 215 484 720.

Heizungsgesetz (GEG) 2026 — Obligations for property owners in Bavaria