This document discusses types of values and purposes of valuation in civil engineering. It outlines several types of values used in estimating and costing, including scrap value, salvage value, market value, book value, potential value, sentimental value, and speculation value. It also provides examples of numerical calculations for depreciation using straight line, constant percentage, and sinking fund methods. The key purposes of valuation are identified as buying or selling property, taxation, rent fixation, and securing loans.