Definition:
Zoning is defined as the creation by law, of the Sections or Zones such as
residential, commercial, industrial, civic, institutional, and recreational in which
the regulations prevent misuse of lands and buildings and limit their height and
densities of population differing in different zones.
Importance of Zoning:
Prevents Misuse: Ensures land and buildings are used appropriately.
Orderly Growth: Promotes the organized development of towns.
Health and Safety: Separates industrial areas from residential to avoid
pollution.
Noise Reduction: Keeps commercial areas away from residential zones.
Population Distribution: Prevents overcrowding in any one area.
Height Regulation: Controls building heights to ensure access to sunlight
and air.
Public Amenities: Coordinates amenities like water, drainage, electricity,
and transport.
Recreational Areas: Allocates land for parks, playgrounds, and other
recreational facilities.
Classification of Zoning:
1. Use Zoning: Divides the city into sections for specific purposes to avoid
encroachment.
2. Height Zoning: Regulates the height of buildings.
3. Density Zoning: Controls the population density in different zones.
(1) Use Zoning:
The main principle of use zoning is to divide the city into different sections or
zones, and utilizing of each of the zone to the right purpose and in correct location
with respect to others so as to avoid the encroachment of one zone upon another
adjoining 1 it.
Created by Saif
Types of Zones:
(i) Residential zone [40-50%] (iv) Civic zone [2-3%]
(ii) Commercial zone [2-5%] (v) Institutional zone [1-2%]
(iii) Industrial zone [5-20%] (vi) Recreational zone [15-20%]
1. Residential Zone:
o Most important section where people live together in large numbers.
o Includes detached single-family houses, semi-detached houses, group
housing, chawl, flats, skyscrapers, etc.
o Covers 40% to 50% of the total land.
o Should be located in peaceful surroundings, away from business or
industrial zones.
o Should have privacy, green belts with parks, and speedy
communication facilities.
2. Commercial Zone:
o Covers 2% to 5% of the area.
o Consists of markets, warehouses, godowns, business offices, banks,
and residential buildings for employees.
o Should be located near traffic centers and along roadsides.
3. Industrial Zone:
o Covers 5% to 20% of the area.
o Next in importance to the residential zone.
o Should be located away from residential areas and planned to ensure
no dangerous gases pass over it.
o Includes minor, light, medium, and heavy industries.
4. Civic Zone:
o Area Coverage: 2% to 3%
o Purpose: Contains public buildings.
o Examples: Townhall, court, public libraries, post office, museum,
auditorium, bank, show-rooms, stores, houses for employees.
5. Institutional Zone:
o Area Coverage: 1% to 2%
o Purpose: Contains educational institutions.
o Examples: Schools, colleges, institutions.
6. Recreational Zone:
o Area Coverage: 15% to 20%
o Purpose: Provides a healthy environment for people.
o Examples: Parks, open spaces.
Created by Saif
Advantages of Use Zoning are:
o It permits the right use of the Land for the right purpose, i.e. big factories
which produce dangerous gases, smoke and noise at all untimely hours will
not be allowed inside the residential zone; business areas will not invade or
encroach upon the residential areas.
Hence it provides the residents a good amount of privacy, open spaces, and
healthy environment.
o Since the use of land is known definitely beforehand. It is possible to
arrange traffic facilities, water-lines, sewer lines and other public utility
services in an efficient way.
o It prevents the encroachment of one zone over the other. So, the land values
are stabilized.
(2) Height Zoning
Besides the use of land, there are other factors such as height, volume of the
building, which need to be controlled. It is done by means of height zoning.
Tall buildings impair the value of small neighboring houses by cutting off
sunshine, air, breeze etc. and thus make the small houses unsuitable for
inhabitation. They make the streets narrow and increase the congestion of traffic.
There are various methods used to control the heights of high rise
buildings. These are:
i) 45° or 63.5° airplane rule
This method uses an angular plane to limit the height of buildings, ensuring
that sunlight and airflow are not blocked in surrounding areas.
Purpose:
Ensures that buildings do not cast long shadows over neighboring properties.
Maintains a sense of openness and adequate sunlight access for pedestrians and adjacent
structures.
Created by Saif
jj) Bulk volume method:
In this case the volume of the building is made equal to the volume of the
prism with plinth area as base and height, equal to the width of the road (1/3
x Area x Height).
Now-a-days the Floor-Space-Index (FSI) or Floor Area Ratio (FAR) is used
to limit the total floor area of the building in relation to open plot area.
Purpose:
Focuses on the total density and mass of buildings rather than rigid height restrictions.
Provides design flexibility while ensuring compliance with urban planning objectives.
Aspect 45° or 63.5° Airplane Rule Bulk Volume Method
Focus Building height and shadow Total building volume and density
impact
Design Limited by height angles High, as long as volume is adhered to
Flexibility
Use Case Ideal for maintaining sunlight Suitable for urban areas with mixed-use
development
Advantages of Height Zoning are:
It does not allow the tall buildings to grow near by buildings of lesser height.
It establishes minimum standards in terms of light, air and space, thereby
creates healthy conditions.
It controls the setback from roads.
It helps to construct the buildings with uniform height. And its harmonious
grouping makes the street picture as pleasing as possible.
(3) Density Zoning
The population per unit area or acres is defined as density of population. This
density may be either gross or net density.
The gross density is the average density of population per unit area of
the residential, including open spaces, and area under non- residential
use such as schools, shops, and other public institutions.
The net density is the average density per unit of the housing area
including local roads only.
Created by Saif
Considering a family consisting of 5 persons living in a plot, the
population in 100 plots will be 5 x 100 = 500. If 20 plots are arranged
per acre, the land required will be 100/20 acres. Hence the net density of
population per acre will be 500/5 = 100. If an area of 5 acres is reserved
for parks, playgrounds, recreation, then the gross density of population
per acre will be 500/10 = 50.
As density of population indicates whether there are normal or over-
crowding conditions, it has an important place in almost every planning,
or re-planning scheme.
To control rapid population growth and ensure evenly distribution of
population through out the city or town in order to reduce pressure in
some areas, it is necessary to take necessary steps.
Density zoning is that through which it can be done.
Advantages of Density Zoning are:
It governs the density of population.
As population is distributed throughout the town, it promotes healthy
conditions.
At prevents over-crowding.
Created by Saif
