The much larger stock of owner-occupied buildings and rented property in locations not favoured by financial institutions is overlooked in private databases. Of course, this is a large and highly varied market and therefore difficult to sample. The stock of property changes through the addition of new buildings, the demolition of existing and the modification of older buildings. There are different routes through which these changes are accomplished: property developers provide speculative and bespoke premises, and occu­ pants may undertake their own developments. There are different types of developer, including public agencies motivated primarily by employment gen­ eration, developers with no long-term interest in the property and developers who are also investors.