• Data reference period
• Geographic localization (Cities/ metropolitan areas)

• NON CONVENTIONAL DWELLING:  Dwelling that doesn¿t come fully within the category of a conventional dwelling, due to the type and precarious construction, either because they are mobile, semi-permanent or improvised, and not meant for human habitation, but as usual residence, at least, by an household at census reference time.
• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).
• HOUSEHOLD DWELLING :  Dwelling that is normally intended to accommodate only one family, on the condition that it is not being used for other purposes at the period of reference.
• HOUSEHOL DWELLING OF USUAL RESIDENCE:  Occupied household dwelling  that  is the usual or main residence of at least one household.
• RESIDENT POPULATION:  Set of persons who, regardless of being present or absent in a given housing unit at the moment of observation, have lived in the place of their usual residence for a continuous period of 12 months prior to the moment of observation, or have arrived to the place of their usual residence during the period of 12 months prior to the moment of observation, with the purpose of living there for a year, at least.
• CONVENTIONAL DWELLING:  Dwelling consisting on a room or suite of rooms and its accessories in a permanent building or structurally separated part thereof, having a separate access to a street (direct or via a garden or grounds) or to a common space within the building (staircase, passage, gallery and so on).

(Resident population in non conventional dwellings of usual residence/ Resident population in housing units of usual residence)*100