Heat pump
What is a heat pump?
A heat pump extracts heat from the environment in the form of air, ground or groundwater. It uses electricity to raise this heat to a higher temperature level and uses it to heat buildings and hot water.
There are three common types. The air-to-water heat pump is the most common and the cheapest. The brine-to-water heat pump uses geothermal energy via collectors or boreholes. The water-to-water heat pump uses groundwater via two wells.
The federal government subsidises installation. Important: as at 21 July 2026, the KfW fundamentally changed the funding conditions (see section 4) - the previously common formula "up to 70 per cent grant" no longer applies unchanged; what matters now is an absolute maximum funding amount per dwelling unit. From 30 June 2026, new heating systems in larger cities must use 65 per cent renewable energy. A heat pump fulfils this obligation to 100 per cent.
1. When a heat pump makes sense or is compulsory
A heat pump is relevant in these cases:
- For new builds, if municipal heat planning does not provide for district heating.
- When replacing a heating system in municipalities with over 100.000 inhabitants from 30 June 2026.
- When replacing a heating system in smaller municipalities from 30 June 2028.
- When voluntarily replacing a functioning oil or gas heating system in return for the climate speed bonus.
- For refurbishments with BEG funding as an individual measure.
- For modernisation to the efficiency house standard with KfW programme 261 or 262.
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2. Technical minimum requirements for the funding
The KfW only pays if the system complies with these values.
| Requirement | Value |
|---|---|
| Seasonal performance factor (JAZ) | at least 3,0 |
| Sound power level | 10 dB below the EU limit (since 1 January 2026) |
| Hydraulic balancing | in accordance with method B (room by room) |
| Smart Meter Gateway | certified |
| Specialist company | required |
| Energy consultant or specialist contractor declaration | required |
The JAZ calculation is based on the building data, not on manufacturer information. The value is calculated by an energy consultant from the Energieeffizienz-Experten-Liste. Without documented hydraulic balancing, there is no payout.
3. The most important authorities and bodies
Kreditanstalt für Wiederaufbau (KfW)
Since 2024, the KfW has been the central body for heating funding in residential buildings and non-residential buildings. It awards grants and interest-reduced top-up loans.
Housing industry info centre: 0800 539 9002, free of charge.
Application portal: Meine KfW
Bundesamt für Wirtschaft und Ausfuhrkontrolle (BAFA)
The BAFA maintains the list of eligible heat pumps and checks technical requirements. For pure heat-pump funding, the KfW has been responsible since 2024; BAFA remains relevant for energy advice and specialist contractor lists.
Energy advice info line: +49 6196 908-1625.
BAFA funding programme at a glance
Untere Wasserbehörde
The untere Wasserbehörde is based at the district office (Landratsamt) or in the independent city (kreisfreie Stadt). It authorises borehole heat exchangers and groundwater wells for heat pumps. It is not responsible for air-to-water heat pumps.
Processing takes between a few days and six months, depending on the type of construction. The fees are usually between 100 and 500 EUR.
Municipal building authority
The municipality's building authority checks noise protection and the minimum distance to the property boundary. The requirements are set out in the building regulations of the relevant federal state. A distance of 3 metres is often required.
Bezirksschornsteinfeger
The Bezirksschornsteinfeger signs off the decommissioning of the old heating system. They are also responsible for the fire safety inspection and for the decommissioning certificate.
4. Funding at a glance
The federal government combines three routes. KfW pays grants when replacing a heating system. BAFA subsidises the associated energy advice. Anyone who does not want a grant can instead claim the costs against tax.
Important - reform as at 21 July 2026: The Federal Government decided on 8 July 2026 new key points for the Bundesförderung für effiziente Gebäude (BEG). KfW will switch its funding products (incl. 458, 459, 522) on 21 July 2026 to new conditions. Anyone who has a valid Bestätigung zum Antrag (BzA) by 20 July 2026 and submits the funding application will still receive the previous conditions. From 21 July 2026, only the new rules described below apply. The following table reflects the position from 21 July 2026 onwards.
Important (unchanged): Always submit the funding application before placing the order. Anyone who signs the supply and services contract without a suspensive condition loses the entire funding. The Verbraucherzentrale calls this the most common reason for rejection.
KfW heating funding 458 (private individuals, residential buildings) - status from 21 July 2026
KfW subsidises the installation of a heat pump in existing buildings. The grant is made up of a basic subsidy and bonuses, capped by an absolute maximum funding amount per dwelling unit.
| Item | Value (from 21.07.2026) |
|---|---|
| Basic subsidy | 30 per cent of the eligible total costs |
| Efficiency bonus (ground, groundwater or wastewater heat pump, natural refrigerant) | no longer applicable since 21.07.2026 |
| Climate speed bonus (owner-occupiers, replacement of a functioning old heating system) | 16 per cent - first reduced on 1.2.2027, then every six months (1.2./1.8.) by 4 percentage points |
| Income bonus (owner-occupiers, no children in the household) | 40 % to 30.000 EUR annual household income, 30 % to 40.000 EUR, 10 % to 50.000 EUR |
| Income bonus (owner-occupiers, with at least one minor child - family supplement of 10.000 EUR to the income) | 40 % to 40.000 EUR annual household income, 30 % to 50.000 EUR, 10 % to 60.000 EUR |
| Maximum funding amount 1. Whousing unit | 28.000 EUR (falls every six months from 1.2.2027 by 750 EUR) |
| Maximum funding amount 2.-6. Whousing unit | each 15.000 EUR |
| Maximum funding amount from 7. Whousing unit | each 8.000 EUR |
| Value creation bonus (planned from Q1 2027) | +15 % for heat pumps manufactured in the EU; basic funding falls to 15 % for devices manufactured outside the EU |
The climate speed bonus and income bonus are only available to owner-occupiers. You provide evidence for the income bonus with the tax assessments from the second and third previous year. The actual payout is capped by the maximum funding amount per housing unit, even if the sum of the percentages is mathematically higher.
KfW heating funding 522 (companies, non-residential buildings) - status from 21 July 2026
Companies and owners of non-residential buildings apply for the heating funding via the programme 522. The maximum funding amount is 28.000 EUR for buildings up to 150 m² net floor area, plus 197 EUR/m² for the area between 150 and 400 m², 118 EUR/m² between 400 and 1.000 m² and 79 EUR/m² above that. The maximum amount falls every six months from 1.2.2027 in correspondingly tiered steps. The application process runs separately from programme 458.
KfW supplementary loan 358 and 359
Anyone who wants to finance their own contribution via a loan uses the supplementary loan. Requirement: a KfW or BAFA grant has already been approved. The loan products themselves are not directly affected in their structure by the reform on 21.07.2026.
| Programme | Target group | Benefit |
|---|---|---|
| KfW 358 (Plus) | Owner-occupiers with household income up to 90.000 EUR | reduced interest rate |
| KfW 359 | Landlords, WEG, others | market interest rate |
| KfW 523 | Non-residential buildings | up to 5 million EUR per project |
5. tax bonus §35c EStG (alternative without KfW)
Anyone who does not apply for a grant can claim the costs against tax. You check the requirements before starting the measure. This rule is not affected by the KfW reform of 21.07.2026.
| Item | Value |
|---|---|
| Tax bonus on costs | 20 per cent |
| Maximum amount per property | 40.000 EUR |
| Allocation year 1 and 2 | 7 per cent each, max. 14.000 EUR |
| Allocation year 3 | 6 per cent, max. 12.000 EUR |
| Minimum age of building | 10 Jahre |
| Requirement | Specialist company, invoice, bank transfer |
| Exclusion | No BAFA or KfW funding for the same measure |
| Period of validity | 1 January 2020 to 31 December 2029 |
6. State-specific funding (in addition to the federal government)
Many federal states have discontinued their heat pump grants 2024 and 2025 in favour of federal funding. Separate grant programmes 2026 only still exist in a few states, but change frequently. Most states instead offer reduced-interest loans via their state development banks.
| Federal state | Programme | Status July 2026 |
|---|---|---|
| North Rhine-Westphalia | progres.nrw Klimaschutztechnik | active, but restricted: geothermal funding now only for multi-family houses from 3 Whousing units, cap 15.000 EUR (existing single-/two-family houses no longer eligible since the redesign 2026) |
| Saxony-Anhalt | Sachsen-Anhalt MODERN (IB-LSA) | active, loans up to 50.000 EUR, first two years interest-free |
| Saarland | SIKB Modernisierung | active, loans up to 75.000 EUR at 1 per cent interest |
| Brandenburg | ILB Wohneigentum (grant + interest-free loan) | active, restructured for 2026-2028 (incl. basic funding 10.000 EUR + child bonus 10.000 EUR/child) |
| Baden-Württemberg | Klimaschutz-Plus für Privatpersonen | expired on 15 July 2025; successor programmes are now only aimed at local authorities |
| Bavaria | 10.000-Häuser-Programm (EnergieBonusBayern) | discontinued in April 2022 |
| Bremen | Landesprogramm Heizungstausch (BAB) | application freeze already since 31 August 2025 (not only since January 2026); new loan programme announced for autumn 2026 |
| Remaining states | Modernisation loan via state development bank | active, without a grant component |
A combination is only possible if the state programme permits double funding. Details on application, sequence and stackability are set out in the relevant federal state document.
7. Local authority funding and municipal utilities (in addition to federal and state)
Some major cities have their own heating replacement or climate protection programmes. Municipal utilities also often award heating installation bonuses or special heat pump tariffs. The differences between cities are sometimes considerable and change frequently - always check the current programme page before submitting an application.
| City | Programme | Status July 2026 |
|---|---|---|
| Hamburg | IFB Erneuerbare Wärme | active; the funding logic is kW-based (not just a flat percentage) - check the exact funding rate and cap with IFB Hamburg before submitting an application |
| Munich | Climate-neutral buildings - the programme is now called FKG (Förderprogramm Klimaneutrale Gebäude); the former name "FES" is no longer current | active, up to 5.000 EUR as a supplement to federal funding |
| Düsseldorf | Klimafreundliches Wohnen und Arbeiten | currently applications suspended - programme is being revised; applications already submitted remain valid |
| Stuttgart | Heizungsprogramm Landeshauptstadt | active, but new system since 1.10.2025: fixed rates per kW instead of percentage funding (e.g. 300 EUR/kW for heat pumps), cap 150.000 EUR |
| Berlin | Effiziente GebäudePLUS und HeiztauschPLUS | stopped for new applications; in addition, as part of the nationwide KfW changeover in early/mid-July 2026 there was a temporary complete stop to heating funding, resumption under new conditions expected from around 21.7.2026 |
| Hanover | proKlima-Fonds | active, basic funding until 3.000 EUR, plus up to 6.000 EUR bonus “Wärmepumpe+” when combined with building envelope measures |
In smaller towns without a municipal programme, it remains the pure federal funding. City-specific conditions, application offices and Stadtwerke tariffs are in the respective city document.
8. Mandatory: the Gebäudeenergiegesetz (GEG)
65 percent rule depending on city size
The GEG links the obligation to municipal heat planning. Two key dates are relevant.
| Municipality | Key date for the 65 percent obligation |
|---|---|
| More than 100.000 inhabitants | 30 June 2026 |
| Up to 100.000 inhabitants | 30 June 2028 |
| Heat planning area already designated | immediately after designation |
From the relevant key date, every newly installed heating system must run on at least 65 percent renewable energy. A heat pump meets this obligation by 100 percent.
Grandfathering and mandatory advice
Existing heating systems may continue to run. Repairs are permitted. The obligation only applies when the system is replaced.
Anyone who wants to install a new gas or oil heating system must first use expert advice. The advice points to municipal heat planning and to the rising CO2 price. The obligation is set out in § 71 A subsection 11 GEG.
9. Permission depending on heat pump type
Air-to-water heat pump
The air-to-water heat pump does not require permission in most federal states. However, you must comply with noise protection under TA Lärm.
| Area type | Daytime (06:00-22:00) | Night-time (22:00-06:00) |
|---|---|---|
| Purely residential area | 50 dB(A) | 35 dB(A) |
| General residential area | 55 dB(A) | 40 dB(A) |
| Mixed-use area | 60 dB(A) | 45 dB(A) |
| Commercial area | 65 dB(A) | 50 dB(A) |
The values apply at the property boundary. The minimum distance to the property boundary is governed by the building regulations law of the federal state, often 3 metres.
Brine-to-water heat pump (geothermal)
Borehole heat exchangers and ground collectors require a permit from the lower water authority at the Landratsamt or in the independent city. The authority checks the intervention in groundwater.
| Component | Procedure | Duration | Fee |
|---|---|---|---|
| Ground collector (shallow) | Notification | a few days | 50 to 200 EUR |
| Borehole heat exchanger (deep drilling) | Water-law permit | 3 to 6 Monate | 200 to 500 EUR |
| Hydrogeological report | external | 2 to 4 W weeks | 1.000 to 3.000 EUR |
Since the Geothermie-Beschleunigungsgesetz (GeoBG) of 23 December 2025, for shallow geothermal collectors up to 4 metres deep outside water protection areas, a notification is sufficient instead of a full water-law permit. The GeoBG amends § 49 WHG and applies nationwide. For deeper, classic geothermal borehole heat exchangers, the full permit requirement under state water law remains.
Water-to-water heat pump (groundwater)
The water-to-water heat pump always requires a water-law permit. The lower water authority is responsible. A prerequisite is a water analysis from an accredited laboratory.
10. Typical costs and own contribution
The following ranges are nationwide empirical values for a detached house, gross and before funding. Since 21.07.2026, the maximum grant has been based on an absolute maximum funding amount per residential unit (28.000 EUR for the first residential unit) instead of a fixed percentage - the actual own contribution depends more strongly than before on individual eligibility for bonuses (income, family supplement, climate speed bonus).
| Design | Costs gross | Funding (indicative value, highly dependent on individual bonus eligibility) | Own contribution (indicative value) |
|---|---|---|---|
| Air-to-water heat pump | 14.000 to 22.000 EUR | Basic funding 30 % plus, where applicable, climate speed and income bonus, capped at max. 28.000 EUR | to be calculated individually, as a rule significantly lower than before the reform for low to middle incomes |
| Brine-to-water heat pump (geothermal) | 18.000 to 33.000 EUR | as above, capped at max. 28.000 EUR | to be calculated individually |
| Water-to-water heat pump (groundwater) | 20.000 to 35.000 EUR | as above, capped at max. 28.000 EUR | to be calculated individually |
| Electricity costs for heating per year | 750 to 1.600 EUR | none | full |
For a reliable own-contribution calculation, the KfW funding calculator with the current bonus rates applicable from 21.07.2026 is recommended.
11. How to apply for the funding step by step
- Commission an energy consultant or specialist company. The expert prepares the Bestätigung zum Antrag (BzA) with the project ID.
- Conclude a supply and service contract. The contract contains a suspensive or resolutory condition that is tied to the KfW funding approval. This condition must not be added afterwards.
- Submit the application in the Meine KfW portal. You upload the BzA, the contract and evidence for bonuses. Applications from 21 July 2026 are subject to the new bonus rates from section 4.
- Wait for the funding approval. You may only start installation after approval.
- Have the heat pump installed. You have 36 Monate from the funding approval to implement it.
- Submit proof of use. The deadline is six months after completion. The expert prepares the Bestätigung nach Durchführung (BnD), you upload all invoices.
The order is crucial. Placing an order before applying for funding rules out funding.
12. Frequently asked questions
What changes on 21 July 2026?
KfW is switching heating funding (including programme 458) to new terms and conditions: the efficiency bonus is discontinued, the climate speed bonus is reduced from 20 to 16 percent, the income bonus is more finely tiered (with a family supplement for households with minor children), and instead of a cap of 21.000 EUR (70 % of max. 30.000 EUR costs) there is now a fixed maximum funding amount of 28.000 EUR for the first residential unit. Anyone who had a valid Bestätigung zum Antrag by 20 July 2026 and submits the application will still receive the old terms and conditions.
What does the Geothermie-Beschleunigungsgesetz (GeoBG) change?
Since 23 December 2025, for shallow ground-source collectors down to a depth of 4 metres outside water protection areas, a notification is sufficient instead of a full water-law permit. Nothing changes for classic, deeper-drilled ground-source probes; the full permit requirement remains in place here.
Do I need an energy consultant for KfW funding?
You need at least a Fachunternehmer-Erklärung. For the Bestätigung zum Antrag (BzA), in many cases the heating engineer carrying out the work is sufficient. For larger refurbishments to an Effizienzhaus standard, a listed energy consultant is compulsory.
What happens if I sign the contract before submitting the application?
You lose the entire funding for this measure. KfW checks the contract date strictly. KfW does not recognise the subsequent addition of a condition precedent.
Can I combine BAFA energy consulting and KfW heating funding?
Yes. The BAFA consultation covers the planning. The KfW funding covers the heating system itself. Both may run in parallel because the programmes relate to different measures.
What happens to my old heating system?
The Bezirksschornsteinfeger decommissions the old heating system. He issues a certificate. For oil heating systems, you must also have the remaining heating oil drained. Disposal is handled by the heating engineer.
How long does approval for a ground-source probe take?
Three to six months. The untere Wasserbehörde checks the intervention in the groundwater. You need a hydrogeological report. Ground collectors without deep drilling can be notified within a few days; since the GeoBG this also applies nationwide to collectors down to a depth of 4 metres outside water protection areas.
When exactly does the 65-per-cent obligation apply to me?
In major cities with more than 100.000 inhabitants from 30 June 2026. In smaller municipalities from 30 June 2028. If your municipality has already designated a Wärmeplangebiet, the obligation applies immediately. Ask the city administration about the municipal heat planning.
What about noise protection for the outdoor unit?
Since 1 January 2026, the heat pump must be 10 dB below the EU limit value for KfW to fund it. Previously, 5 dB was sufficient. TA Lärm applies regardless.
Can I run a heat pump in an old house too?
Yes. The heat pump operates efficiently up to a flow temperature of 55 degrees. In older buildings with high flow temperatures, insulation or replacing radiators is worthwhile beforehand. The energy consultant calculates this individually.
Note on currency
KfW fundamentally reorganised heating funding as of 21 July 2026 (see section 4) - funding amounts and bonus rates continue to change regularly, including every six months on 1 February and 1 August. Before applying, check the current programme page of the KfW and of the BAFA. The information does not replace individual advice.