The Cube method estimating is specific for building projects and aims to overcome the current criticism to the floor area method that does not take into account possible variations of the storey height. The building volume method became very popular in some European countries like in Germany and Switzerland, where building costs are often expressed in cubic meter prices. The total cost of the project will be given by:
Estimate = Volume X Unit Cost (Cost/m3)
External plan area X height X Cost (cost/ m3)
In order to use the method, the building volume must be first assessed and explicit rules exist in some countries for that purpose. Buildings with distinct types of occupation should have corresponding volumes assessed separately, for example, car park areas, shopping areas and office areas in a commercial building. Specific works like excavations, foundations and external works ought to be assessed separately by using cost comparisons or approximate quantities, for example.
Costs per cubic meter may be difficult to find in countries where the method is not current. Actually, such costs depend on a number of variables, like building types, proportion of wall area per floor area, quality of finishes and so on.
Calculation of volume is subject to rules of measurement
> Measured from external
faces of external walls
> Height of the
building is taken from the top of foundation to
-
For pitched roof
·
A point midway between the ceiling and the apex
of roof 2/3 where roof space is un-occupied
·
A point three quarters from the ceiling to the
apex of the roof where roof space is occupied
-
For Flat roof
·
A point 610mm (2feet) above the roof structure
