development analysis can add significantly to the value of land and development, and as such is a crucial tool for landowners and developers. it is an essential step in kevin a. lynch's 1960 book "the image of the city", and is considered to be essential to realizing the value potential of land. the landowner can share in additional planning gain (significant value uplift) via an awareness of the land's development potential. this is done via a residual development appraisal or residual valuation. the residual appraisal calculates the sale value of the end product (the gross development value, or gdv), and hypothetically deducts costs, including planning and construction costs, finance costs and developer's profit. the "residue", or leftover proportion, represents the land value. therefore, in maximising the gdv (that which one could build on the land), land value is concurrently enhanced.