Energy Efficiency & Subsidy Levels 2026

Efficiency House 40, 55 and 70: the levels clearly explained

The Efficiency House does not denote a construction method, but an energy standard. The number indicates how economical your house is compared with a reference building. We explain the levels 40, 55, 70 and 85, the requirements for primary energy demand and heat loss, as well as the additional costs and funding opportunities in 2026.

Compare efficient house offers To the KfW 40 house as a house type

Efficiency House – what does it actually mean?

The term "Efficiency House" (Effizienzhaus) is an energy standard coined by the KfW and denotes not the construction method, but the energy quality of a building. The number after the Efficiency House – 40, 55, 70 or 85 – indicates how much energy the house requires compared with a legally defined reference building. An Efficiency House 55 therefore uses only 55 percent of the energy of this reference house. Crucially: the smaller the number, the more energy-efficient and economical the building is.

Two figures are decisive here. The annual primary energy demand captures all the energy required for heating, hot water, ventilation and cooling – including the losses during the extraction and transport of the energy sources. The transmission heat loss indicates how much heat escapes to the outside via the building envelope of walls, roof, windows and floor slab. Both values relate to the reference building and together define the Efficiency House level.

You should clearly separate the Efficiency House as a standard from a specific house type. If you are interested in a fundable house following this system as a finished model, you'll find the details in our guide to the KfW 40 house as a house type. This page, by contrast, explains the underlying level system.

The Efficiency House levels compared

Level	Primary energy demand	Transmission heat loss	Additional costs	Funding 2026
Efficiency House 40	40%	55%	approx. 8 – 12% above GEG new build	top KfW subsidy level (297/298, 300)
Efficiency House 55	55%	70%	approx. 3 – 6% above GEG new build	effectively matches the GEG new-build standard
Efficiency House 70	70%	85%	approx. 1 – 3% above GEG new build	barely relevant for new builds anymore
Efficiency House 85	85%	100%	only common for existing buildings	refurbishment level for existing buildings

As of 2026, without guarantee. The percentages relate to a standardised reference building; the additional costs are guide values and depend heavily on the provider, floor plan and building technology.

What an Efficiency House 40 must fulfil

In new construction, the Efficiency House 40 is the most demanding common level and, at the same time, the decisive threshold for the highest subsidies. To reach it, the annual primary energy demand may amount to no more than 40 percent and the transmission heat loss no more than 55 percent of the reference building. In practice this means: a highly insulated, airtight building envelope, triple-glazed windows, a controlled domestic ventilation system with heat recovery and efficient heat generation – usually a heat pump, often combined with photovoltaics on the roof.

In 2026, the Efficiency House 55 effectively matches the statutory new-build standard under the Building Energy Act (GEG). It therefore no longer receives separate funding in new construction. Anyone who wants to go beyond the law and receive funding must reach at least EH 40. How the GEG regulates the minimum energy requirements for prefabricated houses is explained in our guide to the GEG for prefabricated houses 2026.

Additional costs per level – and what makes them worthwhile

Every step up costs money. Compared with the statutory GEG standard, the surcharge for an EH 40 usually amounts to about 8 to 12 percent of the construction costs. The good news: many prefabricated house providers already deliver EH 40 standard as standard in 2026, so the actual additional investment often turns out considerably smaller. Set against the costs are permanently low energy expenditure and the low-interest KfW subsidised loans, which usually more than offset the additional outlay over the period of use.

What funding the Efficiency House standard brings

The real economic lever of the Efficiency House lies in the funding. The low-interest KfW loans 'Climate-Friendly New Build' and 'Home Ownership for Families' require at least an Efficiency House 40, in some cases additionally the QNG sustainability seal. Anyone who reaches this level secures considerably reduced terms for their bank loan. A complete overview of all relevant programmes is given by our guide to the grants for building a house.

Alongside the financial advantage, the long-term value carries weight: an Efficiency House 40 uses little energy, is well prepared against rising energy prices and remains in demand on the property market. The legal basis for the energy requirements is the Building Energy Act (Gebäudeenergiegesetz, GEG); the funding conditions are set by the KfW. Manufacturer-neutral information on energy-efficient building is offered by the German Energy Agency (dena) and the portal Energiewechsel of the Federal Ministry for Economic Affairs.

40% of energy demand

An EH 40 uses only 40% of the primary energy of the reference house.

55% for heat loss

Maximum permissible transmission heat loss for EH 40.

8 – 12% additional costs

Typical additional costs of EH 40 compared with the GEG standard.

Maximum funding

EH 40 opens up the strongest KfW subsidised loans.

Your Efficiency House at an affordable price

Tell us about your project – and we'll put together up to 3 offers for you, free of charge, from manufacturers who deliver Efficiency House 40 standard as standard.

Free & non-binding
·
SSL-encrypted
·
Reply within 24 h

Step 1 of 5 · about 25 seconds left until your offers

Which type of prefab house fits your plans?

Personal reply within 24 hours

140 manufacturers in our editorial in-depth comparison
150+ manufacturers covered in our market overview
Free & non-binding — nothing shared without your OK
SSL/TLS-encrypted transfer, GDPR-compliant

Frequently asked questions about the Efficiency House

Answers on Efficiency House levels, requirements, additional costs and funding – concise and as of 2026.

What does Efficiency House 40 mean?

The number after the Efficiency House (Effizienzhaus) shows how much primary energy the building requires compared with a defined reference building. An Efficiency House 40 uses only 40 percent of the primary energy of this reference building and achieves a transmission heat loss of no more than 55 percent. The smaller the number, the more energy-efficient the house is – EH 40 represents the most demanding common level in new construction.

What requirements apply to an Efficiency House 40?

An Efficiency House 40 must meet two central figures: the annual primary energy demand may amount to no more than 40 percent of the reference building, and the transmission heat loss through the building envelope no more than 55 percent. This is made possible by a very well insulated, airtight envelope, triple-glazed windows, a ventilation system with heat recovery and efficient heat generation such as a heat pump, often supplemented by photovoltaics.

What is the difference between Efficiency House 40 and 55?

The difference concerns the permissible energy demand: an EH 40 may use only 40 percent, whereas an EH 55 may use 55 percent of the primary energy of the reference building. In 2026, EH 55 effectively matches the statutory new-build standard under the GEG, while EH 40 as a voluntarily more demanding level unlocks the highest KfW subsidies. The step from 55 to 40 requires stronger insulation and usually additional technology.

Is a KfW Efficiency House 40 eligible for funding?

Yes. In new construction, the Efficiency House 40 is the decisive KfW subsidy level. The programmes 'Climate-Friendly New Build' (297/298) and 'Home Ownership for Families' (300) require at least EH 40 level, and in some cases additionally the QNG sustainability seal. The lower levels 55 and 70 no longer receive funding in new construction, as they correspond to the statutory standard or fall below it.

How high are the additional costs for an Efficiency House 40?

Compared with a house that only meets the statutory GEG new-build standard, the additional costs for EH 40 usually amount to about 8 to 12 percent of the construction costs. With many prefabricated house providers, however, EH 40 standard is already part of the standard equipment in 2026, so the actual difference is often smaller. Set against the additional costs are the highest subsidised loans and permanently low energy costs.

Is an Efficiency House 40 worthwhile compared with 55?

Financially, EH 40 pays off above all thanks to funding: the low-interest KfW loans and the lower energy costs usually more than make up for the additional investment over the period of use. For anyone who cannot or does not wish to use the funding programmes, EH 55 as the statutory standard may be the more economical choice. An individual calculation with your energy efficiency expert brings clarity.

What are primary energy demand and transmission heat loss?

The primary energy demand captures all the energy required for heating, hot water, ventilation and cooling – including the losses during the generation and transport of the energy sources. The transmission heat loss indicates how much heat escapes to the outside via the building envelope (walls, roof, windows, floor slab). Both figures relate to a standardised reference building and form the basis of every Efficiency House classification.

As of 2026, without guarantee. Requirements and funding conditions may change. The binding basis is the Building Energy Act and the current KfW conditions in each case. Prefabricated House is an independent comparison portal and does not replace energy or financial advice.