They are mainly in private ownership, but significant problems are found on some local authority estates, usually as a result of poor design and difficulties in maintenance. At any one time a considerable number of dwellings lie vacant. Usually defined so as to exclude second homes, holiday homes and dwellings whose owners are temporarily absent, in April 1997 there were 640,000 vacant dwellings in the private sector. Not all vacant dwellings could be used. These vacancies are required for the effective operation of the housing market.
Similar vacancies occur in social housing between lettings and are essential to allow mobility.
Some empty properties are in poor condition and need renovating to make them fit for occupation. Some are in areas where people are not looking for housing. Some may be beyond economic repair, awaiting demolition. In social housing, average rents in 1997 were 52.00 per week for new assured tenancies let by housing associations and 41.00 per week for local authority tenancies. Local authorities can also fund capital works for housing using their own resources, such as usable capital receipts and revenue contributions to capital outlay.