Under the terms of Article 416 of the regulations of the Swiss Institute of Engineers and Architects (SIA 416), the common access or circulatory area (Verkehrsfläche - "VF") is effectively that part of the net floor space (Nettogeschossfläche - "NGF") that is used solely for the purposes of access.

In residential buildings this would include, for example, corridors, entrance halls, stairways, ramps, and lift shafts.

Depending on the local planning laws and regulations, common access or circulatory areas need to be taken into account when calculating possible utilisation ratios.