Energy reference area

The energy reference area ( EBF ), also known as the heated gross floor area ( BGF _B ), is the sum of all floor areas of a building that are heated or air-conditioned. The need to define an EBF arises from the desire to determine comparative values ​​in order to be able to evaluate the heating energy requirements of different buildings. The term energy supply area is in Switzerland and Austria in use and can with the in Germany common name of floor space are compared (EnEV).

Calculation of the EBF

The EBF is the sum of all gross floor areas (GFA) , i.e. including the surrounding walls or parapets. If the wall thickness is unknown, the gross floor area can be determined with sufficient accuracy as 1.1 to 1.15 times the net floor area (NGF) - the latter is the sum of the floor areas ( floor area ) of all floor plan levels between the rising components of a building (the difference is the construction base area (KGF) , the area of ​​the structural elements of the building). The construction areas are also included in the energy reference area because, since the thermal insulation is usually attached to the outer shell, they are also heated.

The EBF includes all living rooms, including bedrooms, and unheated rooms whose co-heating is common for use. These are, for example, stairwells if they are separated from the outside air.

The EBF does not include rooms that do not require heating for their use, such as:

• Washing and drying rooms
• Boiler rooms and engine rooms
• Rooms for the storage of fuels
• Garages
• Storage rooms for bicycles, strollers; Private cellar also used as a storage room
• Rooms that are not separated from the outside air such as balconies, porticoes, terraces.

In order to ensure a comparability of the energy demand for complex types of building use, the modification of the EBF / BGF _B with correction factors can be appropriate.

Such correction factors include:

• Part-time correction factor for seasonally heated rooms ${\displaystyle f_{z}}$
• Temperature correction factor for rooms with temperatures that deviate from room temperature (21 ° C) ${\displaystyle f_{t}}$
• Room height correction factor for particularly high rooms ${\displaystyle f_{h}}$

In non-seasonally used residential buildings as well as in schools and office buildings, the use of such correction factors should be avoided entirely.

In the case of particularly high rooms with a height of 3 m or more, the correction factor is determined using the formula . For a room with a height of 6 m applies . ${\displaystyle f_{h}=h/3}$ ${\displaystyle EBF=2*BGF}$

In the case of expanded attic spaces, the proportionate gross floor area is also determined (floor volume ÷ mean height of the attic space). ${\displaystyle EBF=V/h}$

See also

• Thermal insulation perimeter

Literature and standards

• Österreichisches Institut für Bautechnik : Guideline for the calculation of energy indicators. March 1999, number OIB-382-010 / 99, 4.6 Heated gross floor area p. 7 - Calculation according to ÖNORM B 1800 2002. Determination of areas and volume of buildings

Individual evidence

1. ↑ Heinz Priebernig: Calculation of floor space and volume (according to ÖNorm B 1800) . In: Project management · Construction management V . 2005, 1/10 ( web document pdf [accessed December 29, 2009]).