Three criteria have been used commonly for judging the presence of “overcrowding”
If ANY ONE of the 3 criteria is satisfied, it is considered as 'overcrowding present'
1. PERSONS PER ROOM CRITERION
The number of persons in the household is divided by the number of rooms in the house.
The criteria for counting of persons for assessment of sufficiency of living area are as follows:
• An infant (a child under 12 months of age) is not counted.
• Children aged 1–10 years are counted as half a person each.
• All those above the age of 10 years are counted as one person each.
The accepted standards are given in the following Table
Table: Persons per Room Criteria for Assessment of Overcrowding in a Household
2. FLOOR SPACE CRITERION
• Measure the length (L) and breadth (B) of all the rooms. Calculate the floor area of each room by the formula:
Floor area = L × B
• Add up all the room area to calculate the total area.
• Calculate the number of occupants in the same manner as in the previous case.
• Divide the total area by the number of persons residing in the house.
• This will give the floor space per person.
• The accepted standard of floor space per person is given in the following Table
Table: 
The minimum standard for floor area per person has been set as 50 sq feet (5 sq m).
3. SEX SEPARATION CRITERION
According to this criterion, overcrowding is considered to be present if two persons, above 9 years of age, of opposite sexes, not husband and wife, must sleep in the same room.
‘Must sleep in the same room’, means that there is no other option but to share the room.
Note: Rooms used as bedroom, sitting room, prayer room, dining room, servant’s room - all are considered as living rooms and therefore counted and measured for assessing overcrowding. Kitchen, bathroom, latrine, store, garage etc. are not considered as living rooms. However, a room used in common for living purpose and as kitchen or store is also considered as living room.
References:
1. Poornima Tiwari, Shashank Tiwari. Chapter 13, In: Mastering Practicals in Community Medicine. 2nd ed. Lippincott Williams & Wilkins, New Delhi
2. Park K. Environment and health. In: Park’s Textbook of Preventive and Social Medicine, 24th ed. Jabalpur, India: M/S Banarasidas Bhanot Publishers; 2017
3. UN – Habitat. The Challenge of Slums. Available at: http://www.unhabitat.org/categories.as p?catid=671&q=guidelinesovercrowdingfloorar eaperperson. Accessed November 14, 2011.
4. GOI, 2012. Drinking Water, Sanitation, Hygiene and Housing Condition in India. NSS 69th Round; National Sample Survey Office; Ministry of Statistics and Programme Implementation
Modified Kuppuswamy Classification of Socio - Economic Class: http://www.ihatepsm.com/blog/modified-kuppuswamy-scale
Prasad's Scale: http://www.ihatepsm.com/blog/prasad%E2%80%99s-scale
Dependency Ratio: http://www.ihatepsm.com/blog/dependency-ratio
Assessment of Overcrowding in a Household: http://www.ihatepsm.com/blog/assessment-overcrowding-household
Family and the Types of Family: http://www.ihatepsm.com/blog/family-and-types-family
Checking for Mosquito Breeding Areas in a Household: http://www.ihatepsm.com/blog/checking-mosquito-breeding-areas-household
Housefly Breeding Sites: http://www.ihatepsm.com/blog/checking-fly-breeding-sites-household
Life Cycle of Housefly: http://www.ihatepsm.com/blog/life-cycle-housefly
Types of Piped Water supply: http://www.ihatepsm.com/blog/types-piped-water-supply
Reference Indian Adult Man and Woman: http://www.ihatepsm.com/blog/reference-indian-adult-man-and-woman
Concept of the “Consumption Unit”: http://www.ihatepsm.com/blog/concept-%E2%80%9Cconsumption-unit%E2%80%9D
Methods of Dietary Survey: http://www.ihatepsm.com/blog/methods-dietary-survey
24-Hour Recall (Questionnaire) Method: http://www.ihatepsm.com/blog/24-hour-recall-questionnaire-method
Determination of Socio-economic Status of a Family in a Rural Area (the Uday Pareekh Scale): http://www.ihatepsm.com/blog/determination-ses-family-rural-area-uday-pa...
7 Terms used in Maternal and Child Health: Definition and Explanation: http://www.ihatepsm.com/blog/7-terms-used-maternal-and-child-health-defi...
Terms used in Family Health Study: Definitions and Explanations: http://www.ihatepsm.com/blog/terms-used-family-health-study-definitions-...
Lecture on the definitions and explanations of terms used in Family Health Study: http://www.ihatepsm.com/resource/terms-used-family-health-study-definiti...
Hindi lecture on the definitions and explanations of terms used in Family Health Study: http://www.ihatepsm.com/resource/terms-used-family-health-study-definiti...
Hindi lecture on CSC taking: https://www.youtube.com/watch?v=9gvuXrIJ_gY&t=10s
English lecture on CSC taking: https://www.youtube.com/watch?v=rKxXIyJuBz8&t=24s
Format for CSC taking: http://www.ihatepsm.com/blog/format-clinico-social-case-taking-community...
Geriatric CSC taking: http://www.ihatepsm.com/blog/geriatric-clinico-social-case-community-med...