A council estate is a social housing estate constructed by a local authority where the dwellings in the estate are owned and maintained by the council. The concept of social housing has existed in the United Kingdom for around 200 years, but were started to become embraced by the Government in the interwar period as a housing crisis loomed and vast swathes of slums were declared unfit for habitation. Following World War II, the housing crisis deepened as additional properties had been bomb damaged. Since the introduction of the Right to Buy scheme in the 1980s, which allowed residents to purchase their council homes outright, many estates have become multi-tenure, bringing new, different problems for residents and landlords.