The strata area of the unit defined in square metres (sq m) is calculated from the middle of the structural walls. In other words, the common property (or strata boundary) of any unit with another unit or with the common property is calculated to the centre of the floor, wall or ceiling, unless otherwise stipulated in the CPST. The boundary is defined as such to determine the extent of the ownership of a unit. Hence, measuring from the internal walls would give you an area that is different from the official strata area.


For information, strata boundaries not following the centre of the floor, wall or ceiling shall be in accordance with the Diagrammatic plans as approved / authorised by the Chief Planner, Urban Redevelopment Authority (URA). In addition, internal ducts are common properties which should be excluded from your measured area.


Owners are advised to refer to the CPST to know what is included and excluded in the official strata area.