Illegal construction (also known as illegal building or illegal housing) is construction work (or the result of such) without a valid

construction permit Planning permission or developmental approval refers to the approval needed for construction or expansion (including significant renovation), and sometimes for demolition, in some jurisdictions. It is usually given in the form of a building perm ...

. Besides the potential technical hazards on uncontrolled construction sites and in finished buildings, illegal building activity can be a major environmental violation when the works encroach upon preserve areas like nature reserves. Likewise, illegal building can have serious political implications when it is practiced as landgrabbing or for

illegal settling Squatting is the action of occupying an abandoned or unoccupied area of land or a building, usually residential, that the squatter does not own, rent or otherwise have lawful permission to use. The United Nations estimated in 2003 that there ...

in foreign territories (see e.g. International law and Israeli settlements). Illegal building can be the consequence of a combination of urbanization, overpopulation,

homelessness Homelessness or houselessness – also known as a state of being unhoused or unsheltered – is the condition of lacking stable, safe, and adequate housing. People can be categorized as homeless if they are: * living on the streets, also kn ...

and

poverty Poverty is the state of having few material possessions or little income. Poverty can have diverse social, economic, and political causes and effects. When evaluating poverty in ...

in which case expanding slums, Shanty towns or similar will result. On the other hand, illegal building activity may be due to profitable speculation with and resource exploitation, exploitation of valuable real property. Demand for mass tourism accommodation (hotels, etc.) as well as its counterpart, individualistic luxury retreats for the very rich are visible drivers of such speculation. Similar motivation may come from incentives connected with the illegal construction of great shopping malls or similar on greenfield land. Even construction works with apparently valid permits can be a result of bribery. In some cases it can be observed that legal or tolerated settlements are later declared illegal by governmental institutions in order to make room for more lucrative investments or simply for political demonstration purposes (see e.g. Operation Murambatsvina) sometimes under the pretext of beautification.

Notable examples

An infamous example of organized crime, organized illegal construction can be found in the so-called Sack of Palermo.

Environmental risks

Increased landslide risk has been found to be associated with illegal building in hillside regions of population density, densely populated urban areas in Italy and Bosnia and Herzegovina, because of loss of stabilizing vegetation by deforestation, etc.. Due to uncontrolled increase in impervious surface, the role of illegal construction has also been discussed in connection with flash floods (see 2011 European floods#Italy).

Detection

In addition to human observation, large-scale screening for illegal building (activity) can also rely on remote sensing technology using satellite imagery (e.g. from EROS B, IRS-P5,...) and geospatial Geographic information system, information systems.

References

*http://www.jcpa.org/jl/vp498.htm

Notable examples

Environmental risks

Detection

References

See also