Understanding the energy certificate: a complete guide
Every private and public building in Germany needs one: the energy certificate. The document has been mandatory for new builds for over 20 years and for existing buildings for over 10 years when letting or selling.
The energy certificate – sometimes called energy pass or building energy ID – gives a picture of a building’s energy efficiency through various figures. The five-page document also includes recommendations for energy modernisation. Together with the registration number from the German Institute for Building Technology, it is a legally valid certificate for 10 years that proves the building’s energy performance.
What you need to know
What you find in the energy certificate
You will find your way around the five pages more quickly if you know where each type of information is. The first page contains general building information: address, year of construction, systems, number of units, use of renewables and inspection requirements for air conditioning. There are two calculation methods: the demand-based certificate (calculated demand on page 2) and the consumption-based certificate (measured consumption on page 3). Greenhouse gas emissions and use of renewables are also stated. Efficiency classes and the colour scale help compare buildings. Page 4 shows the issuer’s recommended modernisation measures. Page 5 explains all the figures. After reading this guide you will appreciate these as a reference.
Energy quality of the building
Central figures in the certificate are the primary energy figure, the final energy figure and greenhouse gas emissions. The primary energy figure describes the energy used over the building’s whole life cycle – not only consumption in the building but also extraction, conversion and transport. So it reflects how climate-friendly the energy source is. The final energy figure is the key indicator of how efficiently the building uses the energy supplied: the annual energy for heating, ventilation, hot water and cooling per square metre of useful floor area. Greenhouse gas emissions are calculated from the primary energy figure and show the climate impact of operation – mainly CO₂. Renewables reduce emissions.
Primary energy figure
The primary energy figure includes the full energy chain. So a heat pump with electricity from renewables has a much better (lower) primary energy figure than a gas boiler. It is the main basis for the efficiency class and for funding eligibility.
Final energy figure
The final energy figure is given in kWh per m² per year and is the main value for comparing buildings. It is weather-adjusted so that certificates can be compared across Germany. For the consumption-based certificate it is derived from actual consumption over 36 months; for the demand-based certificate it comes from a technical simulation.
Greenhouse gas emissions
Since the 2024 GEG amendment, newly issued certificates must state greenhouse gas emissions per m² per year. They are mainly CO₂ and are calculated from the primary energy figure and the emission factors of the energy sources. Low emissions mean a more climate-friendly building and often better funding.
Estimating heating costs
You can estimate annual energy cost from: annual consumption [kWh] = final energy figure × living area (m²), then cost = consumption × price per kWh of your energy source. The figure is weather-adjusted, so actual consumption can vary with winter severity and user behaviour.
Modernisation recommendations
Page 4 of the certificate lists recommended measures to improve energy efficiency – e.g. insulation, window replacement, heating renewal. These are only recommendations but are useful for planning refurbishment and are taken into account by banks when financing.
Tips for owners and agents
Use the certificate in adverts: the GEG requires key figures (e.g. final energy, efficiency class) to be stated when offering a property. A good class is a selling point; a poor one can be improved with targeted modernisation. The Energyausweis Smart™ helps you obtain the better of consumption-based and demand-based results. For more on documents needed: Documents for the energy certificate.