Known as the "Blue Book" this fourth edition continues with the endorsement from the Association of Cost Engineers. The guide is designed to be an aid for student engineers in the design activities undertaken during their course and help young engineers in industry to compile their own set of cost data. With much of the material in the third edition retained, the major changes are: new cost data; up-dated cost index information (which has been donated by industrialists); and short-cut estimating techniques up-dated. The guide is structured in a straightforward manner and is seen as a starting point. Costing of items should, however, be taken as an approximate guide. Although primarily concerned with capital cost estimating the importance of operating costs in both profitability analysis and optimization studies must not be ignored. A guide to capital cost estimating is also an aid to industrialist. By making reference to various chapters they can cost items, obtain overall plant cost including costing at an R&D stage.