Dr R.K Ludam
Dept Of Community Medicine
Housing And Ventilation
“Housing “ in modern concept includes not
only the physical structure providing shelter
but also the immediate surroundings and the
related community services and facilities.
It may be defined as-” all places in which a
group of people reside and pursue their life
goals; the size of settlement varies from a
single family to millions of people.
The immediate surroundings of residential
building are often referred as neighborhood
WHO expert group (1961) on public health
aspects of housing prefers to use the term
Social Goals Of Housing-:
b) Family Life
c) Access to community facilities
d) Family participation in community life
e) Economic Stability
The Implementation of social goals in housing
requires that govt. should-
- Introduce social housing schemes
- Establish both minimum and maximum standard
- Create financial and fiscal institutions geared to
helping low income people obtain credit for
building and improving their house.
Criteria for healthful housing-:
Healthful housing provides physical protection and
Provides adequately for cooking,eating,washing,and
Is designed,constructed,mantained and used in a
manner such as to prevent the spread of
Provides for protection from hazards of exposure to
noise and pollution
Is free from unsafe physical arrangements due to
construction or mantainance,and from toxic or
Social and economic characteristics such as family
income, family size and composition, standard of
living,lifestyle,stage in life cycle, education and
cultural factors are taken into account.
Because of cultural diversity and other factors such
as climate and social traditions, standard of housing
varies from country to country and from region to
In short-there cannot be rigid, uniform standards
The standards in India are those recommended by
- should be elevated from its surroundings
- should have an independent access to a street of
- should be away from breeding places of mosquito
- should be away from nuisances such as
dust,smoke,smell,excessive noise, and traffic.
- should be in pleasant surrounding
- soil should be dry and safe for founding the structure
and should be well drained.
- The sub-soil water should be below 1o feet
Set Back-: -It is the open space all around the
house which allows proper ventilation and
- In rural areas it is recommended that the built-up
area should not exceed one third of total area.
- In urban areas it is allowed upto two-third of total
- The set back should be such that there is no
obstruction of lighting and ventilation.
Floor-: -Should be Pucca and satisfy the following
- should be impermeable ,so that easy to clean and
- must be smooth and free from cracks and crevices
to prevent the breeding of insects and harbourage
- it should be damp-proof
- the height of the plinth should be 2-3 feet(0.6 t o 1
Walls-: - reasonably strong
- should have a low heat capacity
- weather resistance
- unsuitable for harbor of rats and vermin
Roof-: -Should not be less than 10 feet (3 mtr) in the
absence of air-conditioning for comfort.
- should have a low heat transmittance co-efficient
Rooms-: - should not be less than two,atleast one of
them can be closed for security
- the other may be open on one side if that side is a
- No. should be increased as per the family members
Floor Area-: - should be at least 120 sq ft for more
than one person and at least 100 sq ft for single
- floor area per person should not be less than 50 sq
Cubic Space-:at least 500 c.ft per capita preferably
Windows-: every living room should be provided with
atleast 2 windows and one of them should open directly
on to an open space
- the windows should be placed at a height of more than
3 feet(1 m) above the ground in living rooms
- windows area should be 1/5th of the floor area doors
and windows combined should have 2/5th the floor area.
Lighting-:the daylight factor should exceed 1 % over half
the floor area.
Kitchen-: Must have a separate kitchen
- Must be protected against dust and smoke,
adequately lighted, provided with water supply, provided
with a sink for washing utensils and fitted with
arrangements for proper drainage
Privy-: A sanitary privy is a must for every house,
belonging exclusively to it and readily accessible.
Garbage and refuse-:Should be removed from the
dwelling at least daily and disposed of in a sanitary
Bathing and Washing-: house should have facility for
bathing and washing belonging exclusively to it and
providing proper privacy
Water Supply-: House should have a safe and
adequate water supply available at all times.
RURAL HOUSING-: Minimum standard
- There should be at least two living rooms
- Ample verandah space may be provided
- The build-up area should not exceed one-third of total
- There should be a separate kitchen with a paved sink
or platform for washing utensils
The house should be provided with a sanitary latrine
The window area should be at least 10% of the floor
There should be a sanitary well or a tube well within a
quarter of a ample from the house
It is insanitary to keep cattle and livestock in dwelling
house. Cattle sheds should be at least 25 feet away
from dwelling houses. A cattle shed should be open on
all sides an area 8ft×4ft is sufficient for each head of
There should be adequate arrangement for the disposal
of waste water, refuse and garbage.
Housing and Health
- Poor housing is associated with the following health
Morbidity and Mortality
It refers to the situation in which more people and living
within a single dwelling than there is space for, so that
movement is restricted, privacy secluded, hygiene
impossible rest and sleep difficult.
Overcrowding is a health problem in human dwelling.
It may promote the spread of respiratory infections such
as TB,Influenza and Diphtheria.
House site and construction assistance
Indira Awas Yojna (IAY)-: Introduced in central sector in
1985-86 as part of the rural landless employment
-one room, one kitchen attached with latrine, bathroom
and a smokeless chullah.
It not only means the replacement of vitiated air by
a supply of fresh outdoor air but also control of the
quality of incoming air with regard to its
temperature, humidity and purity with a view to
provide a thermal environment that is comfortable
and free from risk of infection.
Standards Of Ventilation-: Most of the standards
of ventilation have been based on the efficiency of
ventilation in removing body odour.
1) Cubic Space-: minimal fresh air supply ranging
from ‘300’ to ‘3000' c.ft. per hour per person
- De Chaumont advocated a fresh air supply of 3000
c.ft per person per hour.
2) Air Change-: Air change is more important than
the cubic space requirement.
- It is recommended that in the living rooms, there
should be 2 to 3 air changes in one hour; in work
rooms and assemblies 4 to 6 air changes.
If the air is changed more frequently. i.e. More than
6 times in one hour, it is likely to produce a draught
and should be avoided.
The number of air changes per hour is calculated by
dividing the total hourly air supply to the room by
the cubic capacity of the room
a space of 1,000 to 1,200 c.ft. per person is quite
3)Floor space-:Floor space per person is even more
important than cubic space.
- The optimum floor space requirements per person
vary from 50 to 100 sq.ft.
Types Of Ventilation-:
1. Natural Ventilation-: Natural ventilation is the
simplest system of ventilating small dwellings,
schools and offices.
A)The Wind-: The wind is an active force in
- when it blows through a room, it is called
- When there is an obstruction, it bypasses and
exerts a suction action at its tail end - this is called
B) DIFFUSION : Air passes through the smallest
openings or spaces by diffusion.
- This is a slow process and therefore, is not relied
upon as the sole means of ventilation.
C) INEQUALITY OF TEMPERATURE : Air flows from
high density to low density
- The greater the temperature difference between
outside and inside air, the greater the velocity of the
These properties of air are utilised to best
advantage by the proper location of windows,
doors,ventilaiors and skylights.
The chief drawback of natural ventilation is that it is
not possible to regulate the velocity
- Types-: 1) Exhaust ventilation (2) Plenum
ventilation 3) Balanced ventilation (4) Air
1)Exhaust Ventilation-: In this system, air is extracted
or exhausted to the outside by exhaust fans driven
- As air is exhausted, a vacuum is created which
induces fresh air to enter the room through
windows, doors and other inlets.
- Exhaust ventilation is generally provided in large
halls and auditoria for removal of vitiated air.
- The exhaust fans are housed in apertures in the
external walls, high up near the roof which facilitate
2)PLENUM VENTILATION-: In this system, fresh air
is blown into the room by centrifugal fans so as to
create a positive pressure, and displace the
vitiated air. Plenum or propulsion
- plenum is used for supplying air to air-conditioned
buildings and factories.
- Air is delivered through ducts at desired points.
3) BALANCED VENTILATION-: This is a
combination of the exhaust and plenum systems of
- The blowing fan must balance the exhaust fan.
4) AIR CONDITIONING -: Air conditioning is defined
as "the simultaneous control of all”( i.e.-
temperature, humidity, air movement, distribution,
dust, bacteria, odours and toxic gases, most of
which affect in greater or lesser degree the human
health and comfort.)
- Air conditioning is popular in large institutions,
hospitals, industries and dwellings.
- Its use in operation theatres is of particular value in
control of pathogenic organisms in the air.
- Large institutions or hospitals often install central air
conditioning system for entire building
- Where the temperature difference is large between
outside atmosphere and air conditioned room,
"transition room" is sometimes provided.