Heat pumps and the GEG in 2026: no 65-percent duty left, a bio staircase instead of forced replacement

Short answer: Since 29 July 2026 the former Buildings Energy Act has been the Buildings Modernisation Act (GModG). The old §§ 71 to 73 – the 65-percent renewables duty when replacing a heating system, the advice duty before a fossil boiler, and operating bans on certain boilers – have been repealed in the official text. There is no statutory duty to replace a working heating system with a heat pump. A heat pump is one of the ten permitted options in GModG § 42, not the only one.

Anyone who, after 29 July 2026, installs a new gas, oil or LPG boiler in an existing building must meet the bio staircase in § 43: at least 10 percent biogenic or defined hydrogen shares from 1 January 2029, 15 percent from 2030, 30 percent from 2035, 60 percent from 2040. A heat pump, or a heat-pump hybrid meeting § 43(5), satisfies that staircase by another route.

Funding and the invoice are separate questions: Heat-pump funding, Heat-pump costs. Overview: Heat pump.

What changed on 29 July 2026

The amending act was promulgated in the Federal Law Gazette on 28 July 2026 (BGBl. 2026 I No. 226). The federal GEG information portal (BBSR) and the Federal Government describe the same cut:

The live topic Heat pump (dated there 28 July 2026) still presents the 65-percent rule and the two June dates as current. That is not the statute as at 18 August 2026. This tip follows gesetze-im-internet and the BBSR portal, not that hub passage.

Duty, deadline, exception – only what the statute says

No replacement duty for the existing system. § 42(1) applies only when a heating system in an existing building is replaced and the owner chooses one of the options in subsection 2. Repair and continued operation are not prohibited in the fetched § 42.

Ten options on replacement (§ 42(2)): gas/oil/LPG; electrically driven heat pump; solar thermal; biomass or defined hydrogen; heat-pump hybrid; solar-thermal hybrid; high-efficiency CHP; direct electric heating; a building transfer station to a heat network; another innovative solution. Supplementary rules are in §§ 43 to 46.

Bio staircase only for new gas, oil and LPG boilers (§ 43(1)), installed after 29 July 2026 in an existing building:

Exceptions and alternatives that § 43 itself names:

• Solar thermal can meet the duty; for 2029–2034 there are minimum aperture areas (0.04 m² per m² of useful floor area in dwellings with at most two flats, 0.03 m² where there are more than two).
• Ventilation with heat recovery can meet it in 2029–2034 if the recovery rate is at least 73 percent, the performance ratio at least 10, and the system serves the entire floor area.
• Heat-pump hybrid: the duty is treated as met if, at part-load point A under DIN EN 14825, the heat pump delivers at least 30 percent of the peak-load generator’s output (bivalent parallel / part-parallel) or 40 percent in bivalent alternative operation.
• Breakdown: irreparable failure with a new installation between 1 January 2028 and 31 December 2028 → the duty applies only twelve months after installation. Failure from 1 January 2029 → the duty then in force is suspended for twelve months.
• If the owner is not the operator, the operator must meet the duty (subsection 6).
• Subsection 1 does not apply to buildings owned by the Federation, allied forces or a company with a federal shareholding that serve national and alliance defence (§ 42(3)).

The green-gas / green-heating-oil quota (§ 42a) is intended to require suppliers to move to climate-neutral fuels by 2045. The Federal Government writes: details of a separate act by 1 December 2026. This draft has not fetched that ordinance text.

Exemptions appear in § 102. The full wording was not fetched on 18 August 2026 – so no invented hardship catalogue is listed here.

What still applies after the 65-percent rule fell away

These are not installation duties for a heat pump, but they remain in the statute:

• § 60a – operational inspection of heat pumps in buildings with at least six dwellings or units, installed after 31 December 2023: after one full heating season, at the latest two years after commissioning; repeat every five years if there is no remote monitoring. Not for domestic-hot-water or air-to-air heat pumps. Optimisation within one year. Competent persons include SHK trades, chimney sweeps and energy advisers on the dena list.
• § 60b – inspection and optimisation of older water-based heating systems (not heat pumps) in buildings with at least six units: systems from before 1 October 2009 by 30 September 2027; younger systems within one year after 15 years have elapsed. Does not apply where standardised building automation under § 56 is in place, or where the heat pump is already under § 60a.
• § 109 – connection-and-use obligation remains as a heading in the statute. Whether your municipality imposes one is in the local bylaw, not in this tip.
• Municipal heat planning is a planning instrument. It no longer triggers a 65-percent heating duty. Deadlines in the Heat Planning Act were not fetched as statute on 18 August 2026 and therefore are not stated here as installation dates.

Funding is not regulatory law

Even without an installation duty, BEG heating funding continues (KfW 458 from 21 July 2026). FAQ A.2.1 says expressly: the GModG again allows fossil boilers; they are still not funded. Anyone who wants to replace should read Heat-pump funding. What drives the invoice: Heat-pump costs.

What this tip is not

Not a municipal heat plan, not a tenancy-law opinion (§ 559f BGB and CO2 cost-sharing are mentioned on the BBSR portal; that statute was not fully fetched here). Not a revival of the 30 June 2026 duty.