Purpose of Approximate Estimating

• Also known as preliminaries estimates 
• The primary function is to produce a forecast of the probable cost of a future project , efore the building has been designed in detail and contract particulars prepared . 
• An estimate is necessary to give the owner a reasonably accurate idea of he cost to help him decide whether the work can be undertaken as proposed or needs to be curtailed or abandoned , depending upon the availability of funds and prospective direct and indirect benefits . 
• For government works proper sanction has to be obtained for allocating the reqquired amount . Works are often let out on a lump sum basis , in which case the estimator must be in a position to know exactly how much expenditure he is going to incur on them 
• From the estimate of a work it is possible to determine what materials and in what quantities will be required for the work so that the arrangements to procure them can be made . 
• The number and kind of workers of different categories who will have to be employed to complete the work in the specified time can be found out from the estimate . 
• An estimate will help in determinging amount and kinf od equipment needed to complete the work . 
• The estimate of a work and the past experience enable one to estimate quite closely the length of time required to complete an item of work or the work as a whole .