The quantity surveyor prepares schedules of quantities of the various project elements. In some cases, this work is performed in conjunction with that of the cost estimator. In many places in the world, a schedule of quantities is prepared for most types of construction contracts, including lump sum and unit price; in other places the quantity surveyor prepares schedules of quantities for unit-price contracts, while the quantity take-off work for lump-sum contracts is left to individual tenderers. We shall consider this matter again later in this chapter during our discussion of construction document development. Quantity surveys are conducted at various points during the planning and design phase, not just during construction document development. Depending on the stage at which a quantity survey is performed, the quantities might include such detailed information as the number of cubic metres of a certain type of concrete and the number of linear metres of a certain size of communication cable; with less detail available, they might indicate the areas of different types of interior walls or even simply the volume or area of a facility devoted to certain types of use.