KfW 40 QNG: The Comprehensive Guide to Subsidies, Costs, and Requirements

What Does KfW 40 QNG Mean?

If you are looking for financing of a property, there are ways to design the construction so that you qualify for subsidies such as the KfW 40 QNG.

“KfW 40 QNG” refers to a standard for new buildings that consists of two components: an energetic and an ecological standard.

KfW 40 means that it is an Energy Efficiency House. Efficiency House Level 40 states:

• that the primary energy demand is only 40% compared to reference buildings that merely comply with the Building Energy Act (GEG), and

• that the transmission heat loss is only 55% in comparison.

In other words, the energy demand is 60% and the heat loss is 45% lower than in average houses. This is the lowest efficiency house level and thus represents houses with extremely low energy requirements.

These values apply per square meter. There is no standardized house by square meter that serves as a reference. In fact, a virtual reference building is created for every project, based on the actual project and equipped with certain standardized technical characteristics.

QNG stands for “Qualitätssiegel Nachhaltiges Gebäude” (Sustainable Building Quality Seal) and is an addition that designates the sustainability standard of a house. This includes ecological, economic, socio-cultural, technical, and process-related factors.

The certification of a project is based on a registered assessment system for sustainable construction. There are various systems, all of which are approved by the German Accreditation Body (DAkkS) and pursue a common vision of sustainability.

QNG Certification

A house qualifies for the QNG seal if and only if:

• it meets the requirements according to KfW 40.

• it meets the requirements of the “Qualitätssiegel Nachhaltiges Gebäude Plus” (QNG Plus) or the “Qualitätssiegel Nachhaltiges Gebäude Premium” (QNG Premium). Both must be proven by a sustainability certificate. You can find out the difference between Plus and Premium below.

• it is not heated with oil, gas, or biomass.

If all these criteria are met, the property is certified for the “KfW 40 QNG” standard and becomes a worthwhile construction project for which attractive subsidies are available.

QNG Plus and QNG Premium are the two quality levels an object must fulfill. They differ in that QNG Plus certifies above-average quality and QNG Premium certifies significantly above-average quality.

The table below shows the respects in which the two differ. Since the QNG seal is an extremely bureaucratic monster with dozens of individual criteria, we have not listed all (40+) individual points that play a role. We have focused on those that carry the most weight in practice.

As the requirements for QNG Premium are significantly higher, the costs for a project subject to this standard are also significantly higher. In addition to the necessary expert reports proving the life cycle assessment and the like, construction costs are higher too.

This is simply due to the higher requirements. If you have to procure at least 50 % of the wood from sustainable forestry for QNG Plus, it is at least 80 % for Premium. This naturally increases procurement costs, as you have to invest more in sustainable materials. The same applies to other factors such as the recycling share and the type of material, which influences energy demand. In short: higher sustainability requirements mean higher costs.

The construction costs are also not compensated by a higher loan. Whether you choose Plus or Premium does not matter: the loan amount remains the same. Why a premium-qualified property can still be worthwhile is explained below.

Subsidies 2026: KfW 297, 298, 300

If you wish to build or renovate a property according to KfW 40 QNG, three loans provided by the KfW (Kreditanstalt für Wiederaufbau) are available to you. You can find the general information about KfW loans in our general article here.

KfW 297, 298

These loans are intended to finance the purchase or construction of a climate-friendly house. It does not matter whether it is an investment property or an owner-occupied property.

The difference between the loans lies in the type of use. KfW 297 is intended for private individuals who want to use the property themselves. For investors, companies, or potential landlords, however, KfW 298 is provided.

For programs 297 and 298, the presence of the QNG seal significantly determines the conditions. With a QNG seal, you receive an effective annual interest rate of approximately 1,5 % below the market average for a maximum loan amount of 150.000 € (with a term of 16–35 years, 10 years of fixed interest, and 1–5 repayment-free years).

Compared to the promotion of an Efficiency House Level 55, the advantage is even greater. You can also get KfW subsidies 297 and 298 for this efficiency house, but the maximum loan amount is 100.000 € with an interest rate approximately 1.5 % below the market average.

KfW 300

KfW 300 is a loan for climate-friendly home ownership for families, but it has strict income criteria. With the QNG seal, a maximum loan amount of up to 270,000 € is possible, with an interest rate 2–3 % below the market average (with a term of 16–35 years, 10 years of fixed interest, and 1–5 repayment-free years)

Here, too, the savings compared to a non-QNG-qualified object are massive: the interest rate is often lower by 0.5 to 0.7 percentage points!

Conclusion: Is KfW 40 QNG worth it for your project?

The decisive advantage of a QNG property is the "interest gap": KfW loans are often 1,5 – 3 % below the interest rates of commercial banks. Over the first fixed-interest period of 10 years, this saves — depending on the loan amount — amounts in the mid to high five-figure range. 

For KfW 297/98, the QNG seal reduces interest payments over a 10-year period by about 10.000 € to 15.000 €; for KfW 300, the difference is about 15.000 € to 20.000 €.

The QNG seal is not just nice on paper. It is a demanding and costly process. The costs are high and vary additionally depending on QNG Plus or QNG Premium. 

For you, the central question is whether the costs can be compensated by the low interest rates.

The Hurdle: Investment vs. Savings

To ensure the quality of the seal, these additional costs are incurred:

• Certification & Audit: Fees for the QNG auditor and fees from the testing centers (approx. 7.000-12.000 €).

• Building material surcharges: Higher costs for certified, low-pollutant materials.

• Planning effort: Stricter requirements for the thermal envelope and building services.

You should consider beforehand which subsidy you qualify for and calculate whether the upcoming costs are in reasonable proportion to the outcome. Construction costs alone can incur an average of an additional 5.000 € to 15.000 €. 

Your decision should be based on a profitability calculation: Does the interest savings during the first 10 years exceed the one-time certification costs?

The Strategic Difference: When is QNG Premium worth it?

Since you receive exactly the same loan amount for QNG Plus as for QNG Premium in all programs, but the latter also involves considerable extra effort (and extra costs!), the attractiveness depends on your personal situation.

1. Families with children (KfW 300) – The "No-Brainer"

For families, the QNG seal (usually in the Plus version) is almost without alternative. With a loan amount of up to 270.000 € and interest rates near the 0 % mark, the savings compared to the free market are so enormous (approx. 8.000 € interest advantage per year) that the additional costs for the seal are amortized after just two years.

If you are looking to start a family and are seeking a home of your own, then this option is preferable to the 297 subsidy, as both the interest rates and the subsidy amount are considerably higher—the lowest subsidy amount (170.000 €) is already higher than the maximum for an EH40, even with QNG (150.000 €). The gap compared to the EH55 (100.000 €) is even wider. If you also qualify for QNG Premium, you secure the value of your home and, with it, the possibility of selling it profitably in the future.

2. Capital Investors – The Yield Turbo (KfW 298)

Investors use QNG as a key for special depreciation (§ 7b EStG). The combination of extremely low interest rates and massive tax depreciation in the first few years ensures a return on equity that is hardly achievable with conventional new buildings anymore.

Compared to an EH40 without a QNG seal and an EH55, a QNG-certified property is more profitable because you can secure higher subsidies, but also because this qualification represents an investment in the future value of your property. By doing so, you may have already anticipated stricter ecological regulations of the future, making the property a secure investment capable of withstanding such tightening of standards.

3. Owner-Occupiers – Protection against "Value Loss" (KfW 297)

Those who build without subsidies save planning costs today but risk the "Brown Discount" tomorrow: properties without proof of sustainability will be harder to mortgage or sell in the future. The QNG seal here is insurance for value retention. For private individuals who also view their property as a capital investment, QNG is a strong advantage.Ganz genau, du betonst hier den präventiven Charakter der Investition. Man erkauft sich mit den höheren Initialkosten gewissermaßen eine "regulatorische Immunität" für die kommenden Jahrzehnte. 

The same applies here as previously stated: the higher costs incurred now could protect you in the future against stricter regulations and the associated additional expenses.

In summary: If you fully exhaust the KfW loan amounts, the QNG seal is currently the smartest investment on the German construction market. However, without a high credit requirement, it remains an expensive bureaucratic tour de force.