Superficial of Floor Area Method

• the total floor area of the building on all  floors is measured between the internal faces of the enclosing external walls , and it includes internal walls , parititons , columns , stairs , lift shafts , main roof slab . 
• Sloping surfaces such as staircases and terraces are measured flat on plan . 
• A unti rate is calculated per square meter of floor area nad the probable cost fo the buiilding is obtained by multiplying the total floor area by the calculated unit rate  
• Where building varies substantially in quality of finishes , it is advisable to separate the floor areas to enable different unit rates to be applied . 
• it advantages are the makiortyu of items with cost impact are related to floor area . 
• Weaknesses include cannot directly take account of change in plan shape or total height of the building . 
• Difficulties are experienced in building up unit rates because of the need to make allowances for a number variables including site conditions ,constructional methods , materials , quality of finishing and fittings . 
• The following unit rates are given as a general illustration of the application of the method to a specific building . 

- Factory RM 120/00 /ft2

- Bungalow RM 220.00 / ft 2