Energy Efficiency Quick Check: Check Your Property's Energy Class & GEG Obligations in Germany
How energy-efficient is your building — and what obligations do you have under the German Building Energy Act (GEG)? Enter the year built, heating and insulation level and instantly get an estimated energy class (A+ to H), a GEG obligations check and concrete renovation recommendations with costs and subsidies. Free and without an energy performance certificate.
Last updated: February 2026
Enter your building's details to estimate the energy class.
What is the GEG and why does it affect you?
The German Building Energy Act (Gebäudeenergiegesetz, GEG) has been the central set of rules for the energy requirements of buildings in Germany since November 2020. It combines the former Energy Saving Ordinance (EnEV), the Energy Saving Act (EnEG) and the Renewable Energies Heat Act (EEWärmeG) into a single law.
Probably the most important change introduced by the 2024 GEG amendment: since 1 January 2024, every newly installed heating system in new-build areas must use at least 65% renewable energy. For existing buildings, this obligation only takes effect once municipal heat planning is in place, at the latest by 30 June 2026 in large cities (over 100,000 inhabitants) and by 30 June 2028 in all other municipalities.
What does that mean in practice? If you own a property or are looking to buy one, you should know its energy condition precisely. The worse the energy efficiency class, the higher your ongoing heating costs, and the greater the renovation effort that may be coming your way in the years ahead.
Our energy efficiency quick check helps you assess the current energy condition of your building and identify the key areas for action. Free and with no data transfer.
Energy efficiency classes A+ to H: what do they mean?
The energy performance certificate (Energieausweis) assigns each building an efficiency class from A+ (outstanding) to H (very poor). The basis is the final energy demand or consumption in kilowatt-hours per square metre and year (kWh/(m²·a)). The lower the value, the less energy the building consumes and the lower your heating costs.
| Class | kWh/(m²·a) | Rating |
|---|---|---|
| A+ | < 30 | Outstanding |
| A | 30–50 | Very good |
| B | 50–75 | Good |
| C | 75–100 | Satisfactory |
| D | 100–130 | Adequate |
| E | 130–160 | Poor |
| F | 160–200 | Bad |
| G | 200–250 | Very bad |
| H | > 250 | Inadequate |
The German building stock averages around 160 kWh/(m²·a), i.e. class E to F. Around two-thirds of all residential buildings were built before 1979 and have hardly been renovated for energy efficiency, or only in part. The savings potential is correspondingly large.
Note: The EU Energy Performance of Buildings Directive (EPBD) provides for a new, uniform scale from A to G from 2026. The national classes A+ to H will be replaced by this EU system in the medium term.
GEG obligations: what owners need to know now
The GEG contains binding retrofit obligations for existing buildings. Breaches can be punished with fines of up to €50,000. These five obligations are worth knowing:
- 1. Replace boilers over 30 years old (GEG §72): Constant-temperature boilers older than 30 years must be taken out of service. Low-temperature and condensing boilers are exempt. This currently affects all boilers installed before 1996.
- 2. Insulate the top-floor ceiling (GEG §47): If the top-floor ceiling adjoining an unheated attic does not meet the minimum thermal protection under DIN 4108-2, it must be insulated (U-value ≤ 0.24 W/(m²K)). Alternatively, the roof itself can be insulated.
- 3. Insulate heating and hot-water pipes (GEG §69): Uninsulated pipes in unheated rooms (basement, attic) must be fitted with insulation at least as thick as the pipe itself (100% rule).
- 4. 65% renewable energy when replacing the heating (GEG §71): When a new heating system is installed, it must use at least 65% renewable energy. For existing buildings this applies once municipal heat planning is available (at the latest 30 June 2026 or 30 June 2028). Transition periods and exemptions for gas floor heating are provided for.
- 5. Retrofit obligations on change of ownership (GEG §73): In the event of a sale, gift or inheritance, the obligations listed above (points 1–3) must be met within two years of the transfer of ownership.
Exception: Owners who have lived in their detached or semi-detached house themselves since before 1 February 2002 are exempt from the retrofit obligations under §72 and §47, as long as there is no change of ownership.
Fines: Anyone who breaches the retrofit obligations risks fines of up to €50,000. In practice, however, breaches are rarely checked. That may change as energy performance certificates become increasingly digitalised.
The 5 most important renovation measures at a glance
Not every renovation delivers the same benefit. The following five measures have the best cost-to-energy-saving ratio and should be planned in the right order:
- 1. Heating replacement: Switching from an old oil or gas heating system to a heat pump saves 30–50% of heating energy. Cost: approx. €15,000–35,000 (before subsidies). Particularly effective in combination with underfloor or wall heating.
- 2. Facade insulation (ETICS): Up to 35% of heating energy is lost through the external walls. An external thermal insulation composite system reduces transmission heat loss by 60–80%. Cost: approx. €150–250/m² of facade area.
- 3. Roof insulation: Up to 20% of heating warmth escapes through an uninsulated roof. Above-rafter or between-rafter insulation costs approx. €50–200/m² and reduces heat loss by 70–80%.
- 4. Window replacement: Replacing old single or double glazing with triple glazing saves 10–15% of heating energy. Cost: approx. €500–1,000 per window. Most effective together with facade insulation, to avoid thermal bridges.
- 5. Basement-ceiling insulation: The cheapest measure with the fastest payback period. Cost: approx. €30–60/m². Saves 5–10% of heating energy and noticeably improves floor comfort.
Tip: The greatest impact comes from combining several measures. An individual renovation roadmap (iSFP) from an energy advisor shows you the optimal sequence and additionally secures a 5% subsidy bonus per individual measure.
What does an energy-efficiency renovation cost?
The cost of an energy-efficiency renovation depends on the starting condition, the size of the building and the goal. Here is an overview for a typical detached house with 130 m² of living area:
| Renovation depth | Cost (gross) | Saving/year |
|---|---|---|
| Single measure (e.g. roof) | €8,000–17,000 | €400–800 |
| Medium renovation | €40,000–65,000 | €1,200–1,800 |
| Full renovation (KfW standard) | €52,000–130,000 | €2,000–3,500 |
With government subsidies (KfW, BAFA), 15–70% of the costs can be covered. On top of that, you save on heating costs every year, and as the CO₂ price rises the saving grows year after year.
Value increase: An energy-efficiency renovation from class F to B/A raises a property's market value by 10–20% on average. In times of rising energy costs, buyers increasingly pay attention to the efficiency class. A poor energy performance certificate becomes a real price discount.
Subsidies 2026: KfW, BAFA and tax benefits
Germany subsidises energy-efficiency renovation more generously than ever before. The three most important programmes at a glance:
KfW 458: heating subsidy
Grant for replacing the heating with renewable energy (heat pump, biomass, solar thermal, connection to a heat network).
- •Base subsidy: 30% of eligible costs
- •Climate speed bonus: +20% (when replacing a functioning oil/gas/coal heating system or a biomass/gas system at least 20 years old)
- •Income bonus: +30% (household income up to €40,000)
- •Maximum: up to 70% subsidy, max. €21,000
BEG individual measures (BAFA)
Grant for insulation, windows, solar shading, ventilation and heating optimisation.
- •Base subsidy: 15% of eligible costs
- •iSFP bonus: +5% (when the measure comes from an individual renovation roadmap)
- •Maximum: 20% subsidy, max. €12,000 per measure
Tax incentive (§35c EStG)
An alternative to the KfW/BAFA subsidy, with a direct tax saving for owner-occupiers.
- •20% of the renovation costs deductible over 3 years (7% + 7% + 6%)
- •Maximum: €40,000 tax saving per property
- •Requirement: building older than 10 years, work carried out by a specialist company
Combination tip: A KfW/BAFA grant and the tax incentive cannot be combined for the same measure. Check individually which route is cheaper for you. With a high income, the tax option can be more attractive.
CO₂ price 2026+: how your heating costs rise without renovation
Since 2021, building owners and tenants in Germany have paid a CO₂ price on fossil fuels (gas, oil, coal). This price is rising on schedule, and from 2027 a market-based price will be added with EU emissions trading for buildings (ETS-2):
| Year | CO₂ price/tonne |
|---|---|
| 2024 | €45 |
| 2025 | €55 |
| 2026 | €65 |
| 2027 | ETS-2 start |
| 2030 (forecast) | €100–150 |
| 2035 (forecast) | €150–250 |
*Annual extra costs for a detached house with 20,000 kWh of gas consumption or 2,000 l of oil consumption, CO₂ share only.
What is the ETS-2? From 2027, EU emissions trading will be extended to the building and transport sectors. Instead of politically fixed prices, supply and demand will then determine the CO₂ price. Experts expect significantly higher prices than in the previous national system.
Conclusion: Anyone who does not renovate today will easily pay €10,000–25,000 more in heating costs cumulatively over the next 10–15 years. That money would be better invested in an energy-efficiency renovation.
Renovation obligation on change of ownership
When a property is bought, gifted or inherited, GEG §73 applies: the new owners must meet the statutory retrofit obligations (boiler, roof insulation, pipe insulation) within two years of the transfer of ownership.
For buyers: Check the energy performance certificate carefully before buying. If the building is in class F or worse, you must expect renovation costs that go beyond the pure purchase price. Plan for these costs in your budget.
For heirs: The 2-year deadline also applies to an inheritance. Anyone who does not want to use an inherited property themselves, but to sell or rent it out, must still meet the retrofit obligations or inform the buyer about them.
Calculate the total purchase costs including closing costs with our closing costs calculator→EU Buildings Directive (EPBD): what is coming for Germany?
In April 2024, the EU adopted the revised Buildings Directive (EPBD 2024/1275). Member states must transpose it into national law by the end of May 2026 at the latest.
The key points:
- •A new, uniform energy efficiency scale from A to G (instead of A+ to H)
- •National renovation roadmaps: the average primary energy consumption of the residential building stock must fall by 16% by 2030 and by 20–22% by 2035
- •Solar-energy requirement on public and large non-residential buildings by 2027, and on new builds by 2029
- •Phasing out of fossil heating: no subsidies for fossil boilers from 2025, complete phase-out by 2040
What does this mean for you? The energy requirements for buildings will continue to rise across Europe in the coming years. Anyone who renovates now is on the safe side in the long term and benefits from the particularly generous subsidies available right now.
Questions & answers
Frequently asked questions about the energy efficiency quick check
The energy efficiency quick check estimates your property's energy efficiency class from a few building characteristics: building type, year built, heating type, insulation level and living area. You don't need an energy performance certificate (Energieausweis) for it. The calculation is based on the reference data of the IWU/TABULA building typology project for the German residential building stock. The check also examines whether obligations under the Building Energy Act (GEG) apply, shows concrete renovation recommendations with costs and subsidy options, and projects the CO₂ costs over the next 10 years.
The estimate provides a rough orientation with an accuracy of ±1–2 energy efficiency classes. It is based on German average values for the respective building types and construction-age classes. Individual factors such as user behaviour, building geometry, location and partial renovations already carried out can influence the actual result. For a legally binding assessment, you need an official energy performance certificate from a certified energy advisor.
That depends on your heating system. Standard and constant-temperature boilers older than 30 years must be replaced under GEG §72. Condensing and low-temperature boilers are exempt from this obligation. Owners who have lived in their building themselves since before 1 February 2002 are also exempt. The replacement obligation only takes effect on a change of ownership. New heating systems must use at least 65% renewable energy after the relevant heat-planning deadline (GEG §71).
The 65% renewables obligation has applied in new-build areas since 1 January 2024. For existing buildings, it takes effect after the publication of municipal heat planning, at the latest on 30 June 2026 for cities with more than 100,000 inhabitants and on 30 June 2028 for all other municipalities. Until then, gas and oil heating systems may still be installed, but with mandatory energy advice and the risk of rising CO₂ costs.
An air-to-water heat pump typically costs €25,000–40,000 including installation. Through the KfW 458 programme you get: 30% base subsidy + 20% climate speed bonus + 20% speed bonus (until 2028) = a maximum of 70% subsidy on eligible costs of €30,000 = a maximum subsidy of €21,000. With a heat pump costing €30,000, that leaves an own contribution of only €9,000.
The maximum subsidy is 70% of €30,000 in eligible costs = €21,000 through the KfW 458 programme. It consists of: 30% base subsidy + 20% climate bonus + 20% speed bonus. As an alternative to the speed bonus, there is an income bonus of 30% for households with a gross annual income below €40,000. The income bonus and the speed bonus cannot be combined; the total subsidy is capped at a maximum of 70%.
On a change of ownership, three measures must be implemented within 2 years (GEG §73): (1) replacement of boilers older than 30 years, (2) roof insulation to a U-value of at most 0.24 W/(m²K), and (3) insulation of exposed heating and hot-water pipes. The deadline begins with the land-register entry. Non-compliance can lead to fines of up to €50,000.
The CO₂ price is €55/tonne in 2025 and in a corridor of €55–65 in 2026. From 2028, the EU emissions trading system ETS-2 starts and brings market-based prices. Experts forecast €100–160/tonne by 2030 and €200–300 by 2035. For a typical oil heating system (2,000 litres/year), this means: from around €350 in CO₂ costs in 2025 to around €764 in 2030 and around €1,274 in 2035.
No. The quick check provides a rough estimate and is not legally binding. An official energy performance certificate can only be issued by a certified energy advisor. When selling, letting or leasing, an energy performance certificate is required by law under GEG §80. However, the quick check is well suited as an initial orientation, for example before buying a property, to estimate renovation costs in advance.
An energy-efficiency renovation can significantly increase the property value: a jump from energy efficiency class H to B or A can raise the value by 10–20%. Conversely, buildings with a poor energy balance increasingly lose value, as buyers deduct the expected renovation costs from the purchase price. Additional benefits: lower ongoing energy costs, better living quality and future-proofing against rising regulatory requirements.
More tools for your property
Closing Costs Calculator (Germany)
Property transfer tax (Grunderwerbsteuer), notary, land registry and agent commission. Calculated instantly by federal state.
Open toolHome Affordability Calculator (Germany)
Enter your income, equity and target monthly payment. See your maximum purchase price instantly.
Open toolMortgage Repayment Calculator (Germany)
Calculate your monthly payment, remaining debt and the interest vs. principal split across the entire loan term.
Open toolLiving Area Calculator (Germany, WoFlV)
Calculate living area under the German Living Area Ordinance (WoFlV), including sloped ceilings, balconies and terraces.
Open tool