A Quantity Surveyor (QS) is a construction industry professional with expert knowledge on construction costs and contracts. They are not to be confused with Land Surveyors or Land Survey Engineers. Services provided by a quantity surveyor may include: Cost consulting and Cost estimating.
An estimate is a calculation of the quantities of various work and the expenses likely to be incurred thereon. The total of these probable expenses to be incurred on the work is known as the estimated cost of the work. The estimated cost of a work is a close approximation of its actual cost. The agreement of the estimated cost with the actual cost will depend mainly upon the accurate use of estimation methods and correct visualization of the work as it will be done.
The importance of correct estimating is obvious. Underestimating may result in the client getting an unpleasant shock when tenders are opened and drastically modifying or abandoning the work at that stage overestimating may lose the engineer his client or his job or in any case his confidence.
Purpose of Estimating
1) To give a reasonably accurate idea of the cost
2) Estimating materials.
3) Estimating the labour.
4) Estimating the time.