Energy Performance Certificate

Evaluation of the energy efficiency of buildings

The energy efficiency of properties is of great importance in technical building equipment (TGA). In almost all areas, such as lighting technology, ventilation technology or heat supply systems, the energy requirement must be taken into account.

Since 2009, § 16 of the Energy Saving Ordinance (EnEV) in Germany requires written proof of the energy quality of buildings.

The so-called “Energy Performance Certificate”, colloquially also called “Energy Passport”, contains a lot of information about the energy demand for office and residential buildings. It is issued for every new building and every modernisation and is handed over to the new tenant or owner when the building is rented or sold.

Background of the Energy Saving Ordinance (EnEV)

© iStock / adempercem

As part of the energy turnaround , the German federal government is aiming for a nearly climate-neutral building stock by 2050. Energy consumption and greenhouse gas emissions in the building sector are to be significantly reduced.

In the climate package, the Energy Saving Ordinance (EnEV), the Renewable Energies Heat Act (EEWärmeG) and the Renewable Energies Act (EEG) were passed. Since 2012, the energy and climate protection policy has been extended to all EU member states.

The Energy Saving Ordinance regulates, for example, the energy demand and consumption of existing and new buildings, the airtightness of buildings, the structural quality, the quality of building and insulation materials and much more. It also contains the regulations on the energy performance certificate.

Many energy-saving solutions are relatively easy to implement. For example, improving the thermal insulation of exterior walls and glass facades, or lowering the heating system at night or turning it off in summer can save a lot of energy.
The EnEV replaces and combines the Thermal Insulation Ordinance (WSchV) and the Heating Systems Ordinance (HeizAnlV).

What does an energy pass or energy performance certificate contain?

• Information about the building
  

  First of all, information on the type of building, address, building section, year of construction, usable floor space and residential units is provided. It is also checked whether renewable energies are used and how the ventilation / cooling is carried out. The energy pass is kept centrally under a registration number at the German Institute for Building Technology ( Deutsches Institut für Bautechnik).

• Energy requirements of the building
  

  First of all, a scale from A+ to H shows how high the energy demand of the building is. Below this are more detailed values in kWh/(m2·a) and W/(m2·K). The use of renewable energies is also discussed.

• Energy consumption
  

  In the case of existing buildings, the recorded energy consumption of the building is displayed in a colour scale from A+ to H. This is based on previous consumption recordings for heating and domestic hot water. The energy consumption is documented in kWh/(m2·a).

• Issuer’s recommendations
  

  In some energy certificates, the issuer gives the property owner information on how to improve energy efficiency at low cost. The owner should follow the modernisation recommendations, as these lead to an increase in the value of the property.

• Calculation documents (annex)
  

  In the annex you can find data that were used to calculate the energy performance certificate, for example, billing values of previous years as well as an average value called “energy consumption characteristic value”.

What are the advantages of an energy performance certificate?

The energy performance certificate provides more transparency and comparability for planners, builders, owners, landlords, prospective buyers, buyers and tenants of a property. Thanks to the scale from A+ to H and colour gradations from green to red, the energy rating is visible at a glance.

Furthermore, under point 4 “Issuer’s recommendations”, energy saving potentials are shown, thus creating incentives for cost savings and improvements. Due to the explicit listing of the item “renewable energies”, an awareness for alternative energies and environmental protection is ensured.

Building diagnostics and quality assessment

Within the scope of planning and execution of technical building equipment, we offer you an analysis and energy evaluation (energy consulting) of properties.

For the energy performance certificate, the energy demand according to DIN V 4108-6, the heating energy demand according to EN 832, the heating and cooling energy demand as well as the humidification and dehumidification energy demand according to VDI 2067 and the heating load according to DIN EN 12831 are considered.

© iStock / ivansmuk

Heat transfer coefficients (U-value) are calculated for a large number of building components, such as wall structures, floors, ceilings and roofs. The total energy transmittance (G-value) is also used in the climatic calculation for direct sunlight or in winter.

Especially older building objects are often affected by so-called “thermal bridges”. Connection joints with high heat losses between building components, window connections and ceiling integrations must be identified and calculated using a so-called “thermal bridge loss coefficient”.

By carrying out an air tightness test (Blower Door Test), the air tightness can be measured while calculating the ventilation heat losses for the energy performance certificate.

Thermography (thermal imaging) using an IR thermal imaging camera clearly shows where there are deficiencies in the insulation and building fabric.

The energy performance certificate is calculated, e.g. with the innovative energy consulting software Dämmwerk or Ennovatis Planning with CAD and CAFM interface.
Are you looking for an energy expert to assess energy efficiency? In our BAUCON Group, there are specialists working in this field. Get in contact with us.