Informal housing

[2] To have informal housing status is to exist in "a state of deregulation, one where the ownership, use, and purpose of land cannot be fixed and mapped according to any prescribed set of regulations or the law".

[1] While there is no global unified law of property-ownership,[3] the informal occupant or community will typically lack security of tenure and, with this, ready or reliable access to civic amenities (potable water, electricity and gas supply, road creation and maintenance, emergency services, sanitation and waste collection).

UN-Habitat more narrowly defines slum housing as lacking at least one of the following criteria: durability, sufficient living space, safe and accessible water, adequate sanitation, and security of tenure.

For example, in Mumbai, India, fast-paced economic growth, coupled with inadequate infrastructure, endemic corruption and the legacy of restrictive tenancy laws[7] have left the city unable to house the estimated 54% who now live informally.

In 2012, among the total stock of approximately 462,000 single-family homes in Los Angeles, California, there were estimated to be close to 50,000 unpermitted secondary units.