Insome places the market can provide some or all of the affordable housing that isneeded, but in other places it is necessary to make housing available at a costbelow market value, to meet an identified need.”The main categories of affordablehousing are set out in Planning Advice Note 74, available on the Executive’swebsite at http://www.scotland.gov.uk/Publications/2005/03/20796/54073.Affordability, in terms of therents and prices paid by tenants and purchasers, varies from one location to anotherso should be determined in a way which takes account...