Estimators price the cost of construction projects so that the relevant contractor can bid for work at an appropriate level. Their pricing work involves considering the price of materials, dealing with suppliers and doing take-offs from construction drawings so they can accurately estimate the materials involved. This work is mainly office based with occasional site visits and regular busy workloads due to the importance of complying with deadlines for bids. Estimators work for a variety of contractors and can specialise in distinct disciplines – for example main contractor estimators may be from a civil engineering or quantity surveying background, while a mechanical estimator may have worked as a mechanical building services engineer or be from a plumbing background.