This document discusses floor area ratio (FAR), which is a calculation of total building floor area divided by the area of the plot of land. It provides FAR limits and percentages for maximum ground coverage for different types of residential buildings based on plot size. It also discusses setback requirements and concepts like mandatory open space. The benefits of FAR are outlined as promoting sustainable development, guiding growth, and improving environmental and social factors like ventilation, greenery, and liveability. Common misconceptions about FAR and development are also debunked.
3. introduction
The floor area ratio (F.A.R.) is the principal
bulk regulation, controlling the size of
buildings.
F.A.R. is the ratio of total building floor area to
the area of the plot.
What is F.A.R. ?
Total floor area
Total land area
FAR=
BNbC
4. A. Residential building
B. Educational institute
C. Academic
D. Health care
E. Assembly
F. Commercial
G. Industry
H. Storage building
I. Danger useable building
J. Other
occupency type
BNbC
A1 building for one family
A2apartment and flat
A3hostel
A4house of lower income people
A5residential hotel
5. residencial building ( a 1 – a 4 )
Plot Size
Building Type(A1 - A4) [1]
(Residential Building)
Building Type(A5) [2]
(Hotel)
Road width
(metre)
FAR MGC Road width
(metre)
FAR MGC
Sq.m Katha (%) (%)
134m2 or below 134m2 2katha or below 2katha 6.0 3.15 67.5 6.0 2.50 67.5
Greater than134m2 upto 201m2
Greater than 2katha upto
3katha
6.0 3.35 65.0 6.0 2.75 65.0
Greater than 201m2 upto 268m2
Greater than 3katha upto
4katha
6.0 3.50 62.5 6.0 3.00 62.5
Greater than 268m2 upto 335m2
Greater than 4katha upto
5katha
6.0 3.50 62.5 6.0 3.25 62.5
Greater than 335m2 upto 402m2 Greater than 5katha upto
6katha
6.0 3.75 60.0 6.0 3.50 60.0
Greater than 402m2 upto 469m2
Greater than 6katha upto
7katha
6.0 3.75 60.0 6.0 3.75 60.0
Greater than 469m2 upto 536m2
Greater than 7katha upto
8katha
6.0 4.00 60.0 6.0 4.50 57.5
Greater than 536m2 upto 603m2
Greater than 8katha upto
9katha
6.0 4.00 60.0 9.0 5.50 57.5
Greater than 603m2 upto 670m2
Greater than 9katha upto
10katha
6.0 4.25 57.5 9.0 6.00 55.0
Greater than 670m2 upto 804m2
Greater than 10katha upto
12katha
9.0 4.50 57.5 9.0 6.50 55.0
Greater than 804m2 upto 938m2
Greater than 12katha upto
14katha
9.0 4.75 55.0 9.0 7.00 52.5
Greater than 938m2 upto 1072m2
Greater than 14katha upto
16katha
9.0 5.00 52.5 9.0 7.50 52.5
Greater than 1072m2 upto 1206m2
Greater than 16katha upto
18katha
9.0 5.25 52.5 9.0 8.00 50.0
Greater than 1206m2 upto 1340m2
Greater than 18katha upto
20katha
9.0 5.25 50.0 9.0 8.50 50.0
Greater than 1340m2 Greater than 20katha 12.0 5.50 50.0 12.0 9.50 50.0[2]
Any size Any size 18.0 6.00 50.0 18.0 NR* 50.0[2]
Any size Any size 24.0 6.50 50.0 24.0 NR* 50.0[2]
building
construction rules
BNbC
7. residencial building ( a 1 – a 4 )
BNbC
Concept of FARConcept and advantage of FAR
building
construction rules
8. Front
Back
Side
Side
Minimum set back 6.56 feet
Side
Front
Back
Back
Side
Minimum 4.92 feet
Front
Back
Side
Front
road
Minimum 4.92 feet
Minimum 4.92 feet
Front
Front
Back
Side
road
Minimum 4.92 feet
Minimum 4.92 feet
FORAPPROACH
BNbC
building
construction rules
9. BNbC
10 Katha
20 ft wide road
Occupancy
type
Total land area Road weidth
A (residential)
A-1 (Single family
house)
7211.82 sq.ft 20 ft (6.0 meter)
{From saroni- 3( )}K= 4.25 4256.19 sq.ft
Total buildable area (within FAR)
Area of site
FAR =
= FAR Area of selected site
= 30650.24 sq.ft
FAR MGC
4.25 57.5
Total buildable area
(within FAR)
building
construction rules
10. BNbC
10 Katha
20 ft wide road
Maximum ground coverage
Ground Coverage =
Ground coveragewith building x 100
Area of site
57.5 x
=
=
Ground coverage with building
(per floor area)
=
=
7.37
Building height =
7211.82
100
4146.79 sq.ft
Ground coverage through building
4146.79 sq.ft
30650.24 sq.ft
Total buildable area
57.5 %
11. BNbC
for mandatory open space
• If B +C= 50% ( mandatory open space ) then A can be
used as a parking space .Here setback also be included.
B
C
MGC(57.5%)
Mandatory open
space(42.5%)
Mandatory Green
space
(21.25%)
Paved (21.25%)
(50%) (50%)
A
C
B
•There has to be 50% of open ground
12. bnbc
Building type Minimum width
of stair(feet)
A. Residential
A1 SINGLE FAMILY
HOUSE
A2 APARTMENT
A3 HOSTEL
A4 HOUSE(LOW
INCOME)
A5 RESIDENTIAL
3.28
3.77
4
***
4
B. EDUCATIONAL
INSTITUTION 5
C.INSTITUTION
5
D. HEALTH CARE
6.56
E. ASSEMBLY
6.56
F. COMMERCIAL BUILDING
F1.OFFICE
F2.SMALL SHOP AND
MARKET
F3.BIG SHOP AND
MARKET
F4.DAILY NEED
5
5
6.56
5
OTHER 4
Floor height Width of
stair(feet)
Two storied 2.46
Three storied 2.62
Four storied 2.95
Above four storied 3.28
stair
13. podium height
Residential hotel
Plot road width podium height
with parapet
Above 20 katha 18m 12m/39ft
Institutional
Health care
Assembly
Religious building
Any amount of 24m 12m/39ft
commercial Any amount of 6m-28m 12m/39ft
podia
m
39.37 ft
road
Minimum
set back
BNbC
14. starting of far
BNbC
11 people were killed in a
predawn
collapse of a six storey building‐
Building Construction Act 1952
The Act provided regulations regarding set backs,
building heights etc.
Develop, improve and expand city of Dhaka by opening up
congested areas
Laying out of altering streets
Providing open spaces for the purpose of ventilation or
recreation
Demolition or construction buildings
Acquiring land for the said purpose and for
Re housing of persons displaced by the exclusion of‐
improvement schemes.
PRELIMINARY REVIEW OF BNBC 1993
Bangladesh National Building Code (BNBC) of 1993 came into
effect with a gazette notification issued on November 15, 2006.
15. Why F.A.R. is used
sustainable development.
large scale land acquisition
Guide the developments in the
desired directions and plan
corrective steps.
Concern of ‘level of service’
Widths are relatively in all
hierarchy of roads in our cities
TownPlannig.com
16. Creating air circulation passage/tunnel
by increasing set back;
Creating direct sun light passage on open
areas by reducing building footprint;
Reducing urban heat island by recreating greeneries
on open areas, as Mahmud [18] identifies saving
forest and promoting plantation can bring ecological
balance in the city;
Reducing cost of artificial air cooling method
as a result of increased natural ventilation;
Maintaining the existing character of established
residential neighborhoods
Minimizing the out-of-scale appearance of large
homes relative to their lot size and to other homes
in a neighborhood;
Minimizing loss of light and privacy to neighbors
caused by the construction of large homes;
Environmental Benefits
17. Social Benefits
(a) Generating greenery and healthy spaces for walking
(b) Injecting and recreating social space within greeneries
(c) Achieving psychological benefits and wellbeing from open spaces
(d) Creating opportunity for privacy and permeability due to injection of open space.
Mainly determine the density or intensity
of development of an area.
Various tools are used of our
urban areas. using such tools is the optimal
utilization of precious land considering its use,
reuse, misuse, disuse and abuse.
Inter-related aspects such as adequacy of water
supply, sewerage system, solid waste disposal,
road capacity, land availability, harmony with
surrounding developments and other facilities,
amenities and services
How FAR effect on a metro city
Social Benefits
18. MISCONCEPT -1
If F.A.R is low, we cannot go for high-rise development
MISCONCEPT -2
Land value is high and is Sky-rocketing. Hence F.A.R.
has to be increased considerably.
MISCONCEPT -3
If F.A.R. is increased, prices of Flats will come down.
MISCONCEPT -4
Land is precious and scarce; hence F.A.R. has to be
increased considerably to house the exploding population.
MISCONCEPT - 5
If F.A.R. is not increased, the common man cannot afford a
decent shelter.
MISCONCEPTS
TownPlannig.com
MISCONCEPT - 6
If F.A.R. values are not increased considerably, major
projects like it Parks will not come in the city.
MISCONCEPT - 7
Housing industry in private sector is giving employment to many.
Very high F.A.R. can improve the employment opportunities in this sector.
MISCONCEPT - 8
F.A.R. values were reduced considerably, when the
Structure Plan for Kochiwas revised.