Superficial floor area method 0 There are many buildings where the unit of accommodation method is impracticable. 0 For example, warehouse projects or open-plan offices. 0 In these cases, the superficial floor area method is found to be reliable. 0 It is again a popular method due to its simplicity. 0 It is a single rate method which uses cost per sqm

Calculation Steps 0 Calculate the Gross Floor Area (GFA) for the proposed building (measure at each floor level between inside faces of external walls)

Functional area method 0
Here, the basis for costing is not the Total Gross Floor Area (GFA) as in the superficial method. 0 But a refinement of this overall area into the component functional spaces. 0 Functional Area method of estimating combines or integrates the functional unit method with superficial method of estimating. 19 0 Functional area is defined by the AIQS: Australian Cost Management Manual as: Any group of accommodation, which has a common work function within a particular type of building. It includes all circulation necessary within that area.