Anyone selling or letting a property in Düsseldorf or elsewhere in North Rhine-Westphalia cannot avoid the energy certificate. The Building Energy Act (Gebäudeenergiegesetz, GEG) recognises two variants: the consumption-based and the demand-based certificate. The demand-based energy certificate (Bedarfsausweis) assesses a building's energy quality on the basis of its fabric and building services – independently of the occupants' heating behaviour. For certain buildings it is even mandatory. This guide explains clearly and factually when each certificate is required, what the demand certificate contains, what it costs and what owners must observe in listings and at handover.
What is a demand certificate?
The demand certificate – officially the demand-based energy certificate (bedarfsorientierter Energieausweis) – describes how much energy a building requires by calculation under standardised conditions. It is based on a technical analysis of the entire building envelope (external walls, roof, windows, basement and storey ceilings) as well as the building services for heating, hot water and ventilation. Since 1 January 2024 the calculation has been carried out bindingly in accordance with the DIN V 18599 standard.
The result is independent of individual user behaviour. It therefore reflects the actual structural and technical energy efficiency of the property, not the lifestyle of the occupants. This is precisely what makes it meaningful for prospective buyers and tenants: two identical houses receive the same key value, regardless of whether the heating inside is used sparingly or wastefully. Two central figures are stated – the final energy demand and the primary energy demand, each in kilowatt-hours per square metre and year.
Demand certificate vs. consumption certificate – the difference
Both documents are equally permissible under the GEG, but they rely on fundamentally different methods:
- Demand certificate: A specialist calculates the energy demand from the building's structural characteristics. The procedure is more elaborate, but objective and independent of the user. It also provides a sound basis for modernisation recommendations.
- Consumption certificate: Here the actual, measured energy consumption of the past three years for heating and hot water is evaluated and adjusted by a location-specific climate factor. The result depends heavily on heating behaviour – in a poorly insulated but barely heated house the key value can turn out misleadingly favourable.
For buyers and tenants, the demand certificate is therefore the more reliable assessment of the energy fabric. Anyone wishing to present the value of their property credibly often benefits from this robust statement.
When is a demand certificate mandatory?
In principle, § 79 GEG provides freedom of choice between the two types of certificate. There are, however, important exceptions in which a demand certificate must be issued:
- New buildings: Since no consumption data is yet available, a demand certificate is required for every newly constructed building.
- Older small residential buildings: Existing residential buildings that have fewer than five dwellings, for which the building application was submitted before 1 November 1977 and that have not been modernised to the requirement level of the 1977 Thermal Insulation Ordinance (Wärmeschutzverordnung) require a demand certificate.
- Missing consumption data: If no or insufficient consumption data is available for an existing building (for example after a prolonged vacancy), a demand certificate must likewise be drawn up.
Particularly within Düsseldorf's existing stock, with its many one- and two-family houses from the 1950s to 1970s, the second rule frequently applies. Whether a modernisation reaches the WSchV 1977 standard should be examined professionally on a case-by-case basis.
Content: What does the demand certificate state?
The demand certificate is a multi-page, officially prescribed form. Its essential details include:
- Building data under § 85 GEG: address, building type, year of construction, usable floor area, number of dwellings and the principal energy source (e.g. gas, district heating, heat pump).
- Final energy demand in kWh/(m²·a) – the amount of energy the building requires annually at its boundary.
- Primary energy demand in kWh/(m²·a) – including the upstream chain for extracting and supplying the energy source; it reflects overall efficiency.
- Energy efficiency class from A+ to H on a coloured colour-band scale.
- Information on the share of renewable energies and on compliance with the 65 percent renewable-energy rule under § 71 GEG.
- Modernisation recommendations under § 84 GEG – specific, cost-effective measures such as insulation, window replacement or heating renewal. They are purely informative and not mandatory.
Energy certificates issued since the 2024 GEG amendment additionally state information on the building's greenhouse gas emissions.
Energy efficiency classes A+ to H
The energy efficiency class is governed by Annex 10 of the GEG and is based on the final energy key value in kilowatt-hours per square metre and year. The scale ranges from A+ (very efficient) to H (very inefficient):
- A+: below 30 kWh/(m²·a)
- A: 30 to under 50
- B: 50 to under 75
- C: 75 to under 100
- D: 100 to under 130
- E: 130 to under 160
- F: 160 to under 200
- G: 200 to under 250
- H: 250 and above
The classification is identical for demand and consumption certificates. The energy efficiency class must be stated in the property listing and is, for many prospective parties, a first point of orientation – similar to the energy label on household appliances.
Costs and validity
Because its preparation requires a technical calculation, the demand certificate is more elaborate than the consumption certificate. Typical market prices for a standard one- or two-family house are around 300 to 500 euros, whereas a consumption certificate is usually offered in the range of 50 to 100 euros. For larger apartment buildings or non-residential buildings the effort and therefore the price can be considerably higher, because the data collection under DIN V 18599 is more extensive.
Every energy certificate is valid for ten years. If the building undergoes significant energy-related changes during this time and the energy demand is recalculated anyway, a new certificate becomes due under § 80 GEG. An expired certificate may no longer be used for sale or letting.
GEG obligations for sale and letting
When selling, letting, leasing or providing a property on a lease, a valid energy certificate must be presented. Owner-occupied properties that are neither sold nor let are exempt; listed monuments likewise do not require a certificate.
In commercial property listings, the following details must be included under § 87 GEG as soon as a certificate exists:
- the type of energy certificate (demand or consumption certificate),
- the final energy demand or consumption in kWh/(m²·a),
- the principal energy source of the heating,
- the building's year of construction,
- the energy efficiency class.
At the latest during the viewing, the certificate must be presented without being requested, and handed over after conclusion of the contract. Breaches of the energy certificate obligations are administrative offences and can be penalised with fines of up to 10,000 euros. As an experienced partner from Düsseldorf, Richter Immobilien-Transaktionen arranges the appropriate energy certificate as part of a sales or letting mandate and ensures legally compliant mandatory disclosures.
