The functions of MDB Quantity Surveyors are broadly concerned with the control of the cost on construction projects. The methods employed, however, cover a range of activities which may include cost planning, cost benefit analysis and cost estimation.

Quantity surveyors control construction costs by accurate measurement of the work required, the application of expert knowledge of costs and prices of work, labour, materials and plant required, an understanding of the implications of design decisions at an early stage to ensure that good value is obtained for the money to be expended.

The technique of measuring quantities from drawings, sketches and specifications prepared by designers, principally architects and engineers, in order to prepare tender/contract documents, is known in the industry as taking off. The quantities of work taken off typically are used to prepare bills of quantities, which usually are prepared in accordance with a published standard method of measurement (SMM) as agreed to by the QS profession and representatives of the construction industry. Generally a experienced surveyor would facilitate all the skills available to minimize additional costs to project and maintain a first class service for customers.