Estimating by means of priced approximate quantities is always more accurate than by using overall building prices per square metre. Prices given in this section, which is arranged in elemental order, are derived from Prices for Measured Works section, but also include for all the incidental items and labours which are normally measured separately in Bills of Quantities. They have been established with a tender price level as indicated on the book cover. They include overheads and profit but do not include for main contractors preliminaries, for which an example build-up is given in an earlier section.