Energy certificate when buying a home in Germany

The law behind it

The federal ministry for housing states that the GModG replaces the old GEG and that its main new rules have applied since 29 July 2026. The official text on the federal portal still sits at the old “geg” address but is headed GModG, so older guides that cite the “GEG” and old section numbers need a second look. This guide uses the sections as they read on 19 October 2026.

Section 79 states the purpose: certificates inform about the energy properties of a building and allow a rough comparison between buildings. They do not prove that a house is cheap to run. A certificate is issued for ten years, and loses its validity earlier if a major change makes a new one necessary (§ 79(3)).

Which type of certificate

There are two kinds, and for an older house the type may be dictated.

• Demand-based (Energiebedarfsausweis, § 81): calculated from the technical properties of the building.
• Consumption-based (Energieverbrauchsausweis, § 82): calculated from the actual use of energy, from at least 36 months of billing data, with a weather correction for heating.

For a residential building with fewer than five flats whose building application was made before 1 November 1977, the Act requires a demand-based certificate (§ 80(3)). The exception is a building that already met the 1977 heat-insulation standard when completed, or was brought up to it later. For other buildings the owner may choose either type, and may state both.

What the seller or agent must do

Section 80(3) says that if a plot with a building, or a flat, is to be sold, or a building right is to be created or transferred, a certificate must be issued unless a valid one already exists. Section 80(4) sets the timing:

1. Before or at the viewing, the seller or agent shows the certificate or a copy. Displaying it clearly during the viewing counts.
2. Without a viewing, it must be shown without delay.
3. At any time on request, it must be produced promptly.
4. After signing the contract, the buyer receives the certificate or a copy without delay.

If the seller is selling a house with no more than two flats, the buyer must also take part in an information talk about the certificate with an authorised issuer, but only if that talk is offered free of charge as a separate service.

Listings carry their own rule. When an advertisement in commercial media is placed and a certificate already exists, § 87 requires the advertisement to give the type of certificate, the final energy demand or consumption shown, the main heating energy source, for homes the year of construction shown in the certificate, and the efficiency class. The person who is responsible for the advertisement must make sure of this.

Who may issue the certificate

Only some people may issue one (§ 88). They include a person entitled under a state’s building rules to sign energy proofs for new buildings, and graduates in listed fields such as architecture, building engineering or building physics, if they meet training or experience conditions, as well as certain master craftspeople and technicians. The issuer must also take care that the data are correct (§ 83). Ask the issuer which of these entitlements applies; this guide did not read any public register of issuers, so the check is yours to make.

When the duty does not apply

Section 79(4) says that the rules of that part do not apply to a “small building”, and that § 80(3) to (7) do not apply to a listed building (Baudenkmal). A listed house therefore needs no certificate for the sale. The Act defines “small building” elsewhere and that definition was not read for this guide, so for an unusual building ask the building authority.

How to read it

Look first at the type, the date of issue and the efficiency class. Compare the final energy figure with similar houses only, as § 79 intends. A consumption-based certificate says more about the last occupants than about the shell of the house. A demand-based one tells you what the building would use under standard conditions. Neither replaces a survey. Costs of refitting heating and insulation are a separate matter.

Which professional to consult

An architect or building-physics expert can say what a poor class implies for renovation. A property valuer can adjust the price. The notary does not check the certificate, but the sale contract can state whether it was handed over.