Usable building area

The building area is used in Germany as an energy reference area size for residential buildings in connection with the Energy Saving Ordinance. ${\displaystyle A_{\mathrm {N} }}$

It is determined as follows:

${\displaystyle A_{\mathrm {N} }=V_{\mathrm {e} }\cdot 0{,}32/\mathrm {m} }$

${\displaystyle V_{\mathrm {e} }}$(heated building volume) [m³] = volume that is enclosed by the heat-transferring area A (determined according to EnEV 2009 , Annex 1 No. 1.3.1).

If the floor height h _{g is} less than 2.5 m or greater than 3 m, the usable area of the building must be calculated as follows:

${\displaystyle A_{\mathrm {N} }=\left({\frac {1}{h_{\mathrm {g} }}}-{\frac {0{,}04}{\mathrm {m} }}\right)V_{\mathrm {e} }}$

Energy reference areas in Switzerland and Austria

In Switzerland and Austria, the term energy reference area is used, which in residential buildings normally corresponds to the gross floor area ( including the surrounding walls). With storey heights of 3.125 meters, the usable building area is identical to the energy reference area on full storeys.

See also

• Usable area , to determine the floor area according to the relevant DIN 277