Quantity surveyors have the task of managing costs related to building and civil engineering projects. Cost planning and estimation is at the core of quantity surveyors' responsibilities, and this involves calculating costs at the beginning of a project, estimating total costs against the budget and advising the project owner on cost-effective ways to complete the building. Quantity surveyors use several techniques in estimating and minimising the costs of a project.
Employ the take-off technique. Use the design drawings of the project to estimate and calculate the costs of the tools and material that will be used in construction. From these estimated costs, create a Bill of Quantities for contractors to use for tendering, valuation and progress payments.
Apply two methods of estimations. Determine the general dimensions of the construction project. Use the approximate estimation technique to obtain a rough estimation of the cost of the project. Consider using the detailed estimation technique, which takes into account the quantities and costs of all input required by a contractor so as to complete the project. Quantity surveyors use estimation to provide the owner of a project with an accurate judgment of the costs.
Employ value engineering techniques. Study alternative design concepts, materials and methods of constructing a project. Take into consideration the functions of the building, and ensure that the objectives of the owner are not compromised. Quantity surveyors use this technique to ensure that the most cost-effective design, material and construction methods are employed.
Undertake a life-cycle cost analysis. This technique accounts for the cost of acquiring, owning and disposing of a building. Compare alternative cost inputs of a project so as to choose those inputs that enhance net savings. A quantity surveyors is concerned with a project's costs, even after the project is complete, and the life-cycle analysis is one such concern.
Although the professional associations in individual countries use their own standards, generally accepted Standard Methods of Measurement exist for preparing a Bill of Quantities.