Proof of need

Energy Demand Calculation - An energy demand calculation is a mathematical determination of a building’s energy requirements based on standardized conditions. It forms the basis for the demand-based energy performance certificate and assesses the energy efficiency of the building envelope and building services-regardless of individual user behavior. The energy demand certificate is calculated in accordance with the provisions of the Building Energy Act (GEG) and DIN V 18599.

Energy Demand Certificate vs. Energy Consumption Certificate

The GEG recognizes two types of energy certificates:

• Energy Demand Certificate (Energy Demand Certificate): Calculates the theoretical energy demand based on the building’s characteristics-insulation standard of the exterior walls, window quality (Ug value), quality of the insulation in the roof and basement ceiling, type of heating system, and hot water supply. The result is independent of user behavior and thus objectively comparable. It is the more precise tool for assessing a building’s energy performance.
• Consumption certificate: Based on actual energy consumption over the past three years. It is less expensive to produce (approx. 100-200 euros vs. 300-500 euros for the energy demand certificate), but depends on individual heating habits and occupancy-an energy-efficient resident can mask a poor building standard, while a wasteful resident can make a good standard appear worse.

For residential buildings with fewer than five residential units that were constructed before November 1, 1977, and have not undergone energy-efficiency renovations since then, the energy demand certificate is mandatory. For all other residential buildings, there is a choice between the energy demand certificate and the energy consumption certificate.

Calculation and Results

The energy demand certificate is prepared by a qualified energy consultant in accordance with DIN V 18599 or the simplified procedure (DIN V 4108-6 / DIN V 4701-10). The following are systematically recorded:

• Building envelope: U-values of exterior walls, roof, basement ceiling, and windows; proportion of thermal bridges; airtightness (if verified by a blower door test)
• Building Services: Heating type (oil, gas, heat pump, district heating), boiler and distribution efficiency, hot water supply, ventilation system with or without heat recovery, solar thermal system, photovoltaics
• Geometry: Heated volume (Ve), thermal envelope area (A), orientation of the main facade and window areas

The result is reported as final energy demand (kWh/m²·a) and presented on a color scale ranging from A+ (below 30 kWh/m²·a) to H (above 250 kWh/m²·a). In addition, the greenhouse gas emissions (kg CO₂ equivalent/m²·a) are specified, which have become increasingly important since the 2023 GEG amendment.

Energy Performance Certification for New Buildings and KfW Funding

For new buildings, the energy demand verification is a mandatory component of the building permit documents-the architect or energy consultant must demonstrate that the building meets the GEG requirements. For KfW funding (Federal Funding for Efficient Buildings, BEG), energy efficiency classes such as KfW 55 or KfW 40 must be substantiated by the energy demand verification. A consultant certified by dena as an energy efficiency expert must confirm compliance and approve the subsidy application. The quality of the energy performance certificate thus directly determines the amount of KfW funding that can be obtained.

Energy Efficiency Classes According to Energy Performance Certificate (GEG 2023)

Class	Final energy demand (kWh/m²·a)	Typical building	Market value effect in Nuremberg
A+	under 30	KfW 40 new construction, passive house	+10-15% vs. market average
A	30-50	KfW 55 new construction, renovated older building	+5-10%
B	50-75	New construction to GEG 2023 standard	Approx. market average for new construction
C	75-100	Well-insulated older building (1990s)	Market average
D	100-130	Renovated older building (1970s/80s)	Slight discount
E	130-160	Unrenovated older building (1970s)	−5 to −10%
F	160-200	Older building pre-WSchV 1977	−10 to −20%
G	200-250	Older building with poor energy efficiency	−15 to −25%
H	over 250	Unrenovated older building from before 1960	−20 to −30%

Practical tip for property owners in Nuremberg and Franconia

We recommend that property owners in the Nuremberg metropolitan area have an energy demand certificate prepared when selling or re-leasing a property-even if an energy consumption certificate would be legally sufficient. The energy demand certificate provides buyers and tenants with a more objective assessment and includes specific modernization recommendations that serve as added value during marketing. The cost is approximately 300-500 euros for a single-family home and approximately 400-700 euros for a multi-family home. Qualified energy consultants from the dena expert list are available throughout the Nuremberg metropolitan region - the Bavarian Consumer Advice Center in Nuremberg also connects clients with reliable professionals.

Frequently Asked Questions

When is an energy performance certificate required?

An energy performance certificate is required for residential buildings with fewer than five residential units that were constructed before November 1, 1977, and have not since been brought up to the standards of the 1st Thermal Insulation Ordinance of 1977 (WSchV 1977). For new buildings, the energy demand certificate is issued as part of the GEG certification anyway and is included in the building permit documents. Anyone applying for KfW funding for a new building must have an energy consultant from the dena expert list prepare and certify the energy demand certificate.

How long is an energy performance certificate valid?

An energy performance certificate-whether a demand certificate or a consumption certificate-is valid for ten years from the date of issuance. In the event of significant energy-related changes to the building (e.g., window replacement, facade insulation, replacement of the heating system with a heat pump), a new certificate should be issued, even if the old one is still valid. The new certificate reflects the improved energy performance and can serve as a selling point when selling or re-leasing the property-properties with an A or B rating command significantly higher prices in Nuremberg locations than energy-inefficient properties.

Who is authorized to issue an energy performance certificate?

Architects, engineers, master craftsmen in certain trades (e.g., heating installation, electrical engineering), and specially qualified energy consultants listed in the Federal Energy Efficiency Expert List (www.energie-effizienz-experten.de) are authorized to issue certificates. We recommend hiring an issuer with proven experience and an entry in the dena expert list, as this list imposes the strictest qualification requirements and is mandatory for KfW subsidy applications. The costs for the energy performance certificate are tax-deductible as business expenses for rented properties.

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