QNG-PLUS, QNG-PREMIUM and Effizienzhaus: what does each label prove?

An Effizienzhaus level such as EH 40 is an energy standard: a calculation, confirmed by an energy-efficiency expert, of how little energy the building needs compared with a reference building. The Qualitätssiegel Nachhaltiges Gebäude (QNG, the federal sustainable building seal) is a sustainability certificate, awarded at PLUS or PREMIUM level by an accredited certification body once the finished building has been checked. The energy certificate (Energieausweis) is a third, statutory document. Each proves something different. None proves that an investment works, and a brochure saying "QNG-PLUS planned" proves nothing yet.

This guide covers sustainability certification for new builds. For reading an energy certificate, see energy certificates for rental investors.

Effizienzhaus is a funding standard. For an Effizienzhaus 40, annual primary-energy demand may be at most 40 per cent, and transmission heat loss at most 55 per cent, of a reference building calculated under the building energy law (KfW technical minimum requirements). An energy-efficiency expert (Energieeffizienz-Experte) from the federal expert list checks and confirms it. In KfW's new-build programme, that means one confirmation before the application (Bestätigung zum Antrag, BzA) and another after completion (Bestätigung nach Durchführung, BnD) (KfW 297/298 product sheet).

QNG is a sustainability seal. It belongs to the Federal Republic of Germany, represented by the federal building ministry (BMWSB), which does not assess buildings itself. Certification bodies accredited through the German Accreditation Body (DAkkS) do that, using rating systems registered for the seal (QNG certification). For residential buildings these are DGNB, NaWoh and BiRN's BNK system; BNB is registered for non-residential buildings. Beyond energy, QNG covers life-cycle greenhouse-gas emissions, sustainable materials, harmful substances in building materials and accessibility.

The energy certificate is a legal duty. For a new building, the owner must have a demand-based certificate issued promptly after completion (§ 80(1) GModG). By law it serves only as information and a rough comparison (§ 79(1) GModG). It is neither the KfW confirmation nor a QNG certificate.

PLUS marks above-average and PREMIUM significantly above-average sustainability quality (QNG FAQ (German), no. 3.1). For residential buildings, the main differences are (QNG requirements, in German):

• Life-cycle emissions: at most 24 kg CO₂-equivalent per square metre a year for PLUS, 20 for PREMIUM.
• Non-renewable primary energy over the life cycle: at most 96 kWh per square metre a year for PLUS, 64 for PREMIUM.
• Timber: at least 50 per cent (PLUS) or 80 per cent (PREMIUM) from certified sustainable forestry.
• Harmful substances: PLUS relies on contractual obligations and written contractor declarations; PREMIUM needs evidence for every newly installed material.

For an investor, the gap is narrower than it sounds. KfW's QNG tier and the special depreciation under § 7b each accept either level, so PREMIUM brings no larger loan or allowance (KfW 297/298 product sheet; BMF letter of 21 May 2025, no. 19). Neither level says anything about price, rent or resale value.

QNG describes the process as follows (QNG for developers; FAQ, no. 3.3):

1. The developer chooses a certification body and, usually, a sustainability adviser.
2. A pre-check of the plans and a target agreement fix the intended level, and the project is registered.
3. During construction, contractors are bound to the requirements.
4. After completion, the adviser submits the evidence. The certification body runs a conformity check (Konformitätsprüfung) and, if the building passes, awards the seal.

Final certification is possible only once documents show the qualities actually built into a completed, fully usable building (FAQ, no. 6.1). Before that, the only option is a temporary planning certificate (QNG-Planungszertifikat). It can be issued from the building permit at the earliest, and it ends if the building deviates materially from the certified design, if the permit lapses, and in any case after five years (FAQ, no. 6.3).

Developers may use the PLUS or PREMIUM marks only under a licence agreement with the certification body, which can cover a certified building or a certified design (FAQ, no. 6.5). A logo in a brochure can therefore rest on the plans alone.

So there are three states: a target, a checked plan (registration or planning certificate) and a checked building. Only the last is evidence of what was built.

KfW 298, the new-build loan for landlords, has three tiers (KfW 297/298; product sheet):

• Climate-friendly residential building (Klimafreundliches Wohngebäude): EH 40, life-cycle emissions within 24 kg CO₂-equivalent per square metre a year and no fossil or biomass heating; up to €100,000 per unit.
• The same with QNG: plus a QNG-PLUS or PREMIUM certificate; up to €150,000 per unit.
• The temporary EH 55 tier: up to €100,000, for applications received by 31 December 2026 at the latest, earlier if federal funds run out (KfW).

At completion, the expert's BnD confirms the standard and, for the QNG tier, that a certificate from an accredited body exists. KfW tells the expert to check that its level, building address and the body's accreditation match (technical minimum requirements). A buyer is liable to KfW for the standard, so KfW recommends a contract clause making the seller liable for the agreed tier, and borrowers keep the documentation for ten years after approval (product sheet). Programme choice is covered in KfW programmes for rental property and the application sequence in KfW 298 for a new rental apartment.

Special depreciation under § 7b EStG. For building applications filed from 2023 to 30 September 2029, the flat must lie in a building meeting Effizienzhaus 40 with a sustainability class, proven by QNG (§ 7b(2) no. 2 EStG). The Federal Finance Ministry accepts either level and says certification follows completion, based on the qualities actually built (BMF, no. 19). EH 55, or EH 40 without QNG, is not enough. The letter does not say how the EH 40 part is evidenced, so keep the expert's confirmation as well. The application date, cost ceiling, completion-year purchase and ten years' letting are separate tests: see Sonder-AfA under § 7b.

No label shows that your KfW application reached KfW before you signed, that the costs stay under the § 7b ceiling, or that the price and rent make sense.

Most of this sits with the developer, and it is easiest to obtain before you sign. During a purchase in Berlin, Dresden or Leipzig, Alpha Minoris's Buyer's Agent service can request the certification status and these supporting documents from the developer and pass them to your energy-efficiency expert, lender and tax adviser (Steuerberater). You need not live in the city. Alpha Minoris does not certify buildings or confirm funding or tax eligibility; those judgements stay with the certification body, the expert, KfW and your Steuerberater.

• Ask for the status in writing: registered or not, with which body and rating system, at which level, and when the conformity check is expected. If the developer cannot name a certification body before you sign, treat QNG as unlikely.
• Put the target into the contract with a remedy if it is missed, and have your own lawyer review the clause.
• Price the apartment without the benefit. Do not pay extra for a label that does not yet exist.
• Check the timing. The final certificate follows completion, while the tax return depends on it. Ask your Steuerberater how a late certificate affects the claim.

Illustrative example. Fictional figures. Apartment B: Leipzig, 50 m², bought off-plan from a developer for €250,000. Developer's building application filed in 2024; purchase contract notarised Thursday 6 March 2025; completion and transfer of benefits and burdens 1 November 2026; let from completion. Assumed, as in our Sonder-AfA guide: the building is designed to EH 40 with a QNG-PLUS target, and the buyer finances without KfW.

In the Sonder-AfA guide, B's allowance is €10,000 a year for four years. It depends on the final certificate, not on the brochure, the target agreement or a planning certificate. If the building fails or the certificate never arrives, Sonder-AfA falls away, while ordinary depreciation continues.

Before you sign for a new-build apartment, ask the developer which labels are awarded and which are only planned, and get the documents in writing. Discuss your first rental property with Alpha Minoris.