🔥 Heating, Building Modernisation Act and funding
In brief
On 10 July 2026 the Bundestag and Bundesrat passed the Gebäudemodernisierungsgesetz (Building Modernisation Act). It was promulgated on 28 July 2026 (BGBl. 2026 Nr. 226); the first stage has been in force since 29 July 2026. Further rules follow from 1 January 2027.
The requirement to run new heating systems with 65 percent renewable energy has been dropped. You may again choose between a heat pump, district heating, biomass, gas or oil. The obligation to replace old gas and oil heating systems no longer applies.
From 2029, new gas and oil heating systems must increasingly use climate-neutral fuels (bio-staircase). From 2045 fuels must be entirely climate-neutral; by 1 December 2026 a law is to oblige fuel suppliers to do so (§ 42a GModG). This obligation falls on the suppliers, not on the owners.
The 65 percent requirement has been dropped under regulatory law, but remains a condition for KfW funding 458. From 1 January 2028, landlords bear half of the gas network charges and CO2 costs; for landlords this is a new burden. New buildings are to be built as zero-emission buildings: from 2028 according to an official standard, from 2030 all
Funding (KfW, programme 458) continues, with changed rates since 21 July 2026.
Step by step
- Use energy adviceGet advice before replacing your heating. Check the costs over the whole lifetime.
- Check fundingFind out before buying what is funded. An application normally comes before placing the order.
- Obtain quotesCompare quotes and watch the bio-staircase for gas and oil.
- As a landlord, plan costsAs a landlord, note the new cost rules from 2028 and 2029.
Deadlines
- The funding conditions are changing: eligible maximum costs €28,000 instead of €30,000, falling every six months by €750 from 21 July 2026. Climate speed bonus 16 percent, falling every six months by 4 percentage points from February 2027. Basic funding for heat pumps from Q1 2027 15 percent. Efficiency bonus and emission reduction supplement are dropped.
- State-law solar obligation: Berlin (SolarG, since 1 January 2023) new buildings over 50 m² usable area and substantial roof conversions, at least 30% of the roof area; NRW § 42a BauO NRW for new residential buildings since 1 January 2025, for fundamental roof renovation since 1 January 2026 (SAN-VO NRW); Bavaria Art. 44a BayBO only for new non-residential buildings as an obligation, for residential buildings a target without sanction. Other states not checked.
- From 1 January 2028, landlords bear half of the gas network charges and CO2 costs (according to the Bundestag), not the tenants.
In depth · legal basis, figures and practice – for advisers and professionals
Legislation
The Bundestag and Bundesrat passed the Heizungsgesetz amendment (Gebäudemodernisierungsgesetz, GModG) on 10 July 2026 (Bundestag with 323 votes in favour and 271 against). Promulgation on 28 July 2026, BGBl. 2026 Nr. 226; the first stage has been in force since 29 July 2026, further GModG rules apply from 1 January 2027. The blanket 65 percent requirement was dropped; continued operation and new installation of oil and gas heating systems remain possible in the long term, a complete replacement obligation no longer applies. Bio-staircase: 10 percent (2029), 15 percent (2030), 30 percent (2035), 60 percent (2040). From 1 January 2028, landlords and tenants each bear half of the gas network charges and CO2 costs; for landlords this is a new burden. From 1 January 2029 to 31 December 2039, landlords bear half of the extra costs of the bio blend, only up to a fuel share of at most 30 percent. Fuels must be entirely climate-neutral from 2045; under § 42a GModG a law is to oblige fuel suppliers to do so by 1 December 2026 (obligation of the suppliers, not of the owners). New-build standard zero-emission building: from 2028 official, from 2030 all buildings. The 65 percent requirement has been dropped under regulatory law, but remains a funding condition of KfW funding 458.
State-law solar obligation (BY / NRW / BE)
Berlin: SolarG since 1 January 2023, new buildings over 50 m² usable area and substantial roof conversions, at least 30 percent of the roof area. NRW: § 42a BauO NRW, new residential buildings since 1 January 2025, fundamental roof renovation since 1 January 2026 (SAN-VO NRW). Bavaria: Art. 44a BayBO, obligation only for new non-residential buildings; for residential buildings a target provision without sanction.
Funding
According to the Federal Government, the Bundesförderung für effiziente Gebäude (BEG, federal funding for efficient buildings) continues: basic funding 30 percent; income bonus up to €30,000 40 percent, over €30,000 to €40,000 30 percent, over €40,000 to €50,000 10 percent; climate speed bonus 16 percent; total funding rate since 21 July 2026 at most 80 percent (capped). Child allowance of €10,000; eligible maximum costs lowered from €30,000 to €28,000 and falling every six months by €750 from 21 July 2026; efficiency bonus and emission reduction supplement are dropped; basic funding for heat pumps from Q1 2027 15 percent; climate speed bonus falling every six months by 4 percentage points from February 2027. According to ADAC and other secondary sources: maximum grant €22,400 for the first housing unit; application via KfW programme 458. The official KfW leaflet was not evaluated here: check the current conditions with the KfW.
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