What are Residential Building Bye-laws?

As per the definition, building bye-laws are the rules set forth by the government authorities, city corporation and developing authorities, for example Ahmedabad Urban Development Authority (AUDA). These norms are tools that control the various aspects of building to ensure the health and safety of general public and visitors.

Also, to ensure the necessary protection to the labourers before starting and during construction. This provides orderly growth of a city.

Objectives of Building Bye-laws

• Allows planned growth

• Prevent haphazard planning of city

• It ensures the safety from fire, noise, health hazard, etc

• It ensures the appropriate climatic design of building

Building Bye-laws Include Norms Related to the Following

• Floor Area Ratio (FAR) or Floor Space Index (FSI)

• Building frontage line

• Minimum plot size

• Built up area of building

• Height of building

Let’s Understand Each Term and Bye-laws,

Floor Space Index

As per GDCR 2021, FSI means the quotient of the ratio of the combined gross built-up area of all floors, to the total area of the Building-unit.

Floor Space Index = Total built-up area of all floors / Area of the Building-unit

What is FSI? - Example Calculation for a Building - Civilology

Permissible Ground Coverage

As per Planning Regulation 10.5.1

For Building‐units with area 500 sq.mts or less

In case of open or partially built plot, the ground coverage shall be the entire area of the Building‐unit.

As per Planning Regulation 10.5.2

For Building‐units with area more than 500sq.mts and up to 1500 sq. mts

The permissible ground coverage shall be up to maximum 75% of the entire building‐unit area.

As per Planning Regulation 10.5.3

For Building‐units with area more than 1500sq.mts

The permissible ground coverage shall be up to maximum 65% of the entire building‐unit area.

Maximum Permissible Building Height

As per table in Planning Regulation 10.6

No.	Road Width (in meters)	Maximum permissible building height (in meters)
1	Up to 7.5mts	Twice the width of the abutting road or open space
2	Above 7.5mts and up to 12mts	15.0
3	12.0mts and above	25.0

Margins

As per the Planning Regulation 13.3.1

Road side margin for residential uses are as below

No.	Road width (in meters)	Road Side Marginfor Building-unitarea up to2000sq.mts andbuilding height upto 25m (in meters)	Road Side Marginfor Building-unitwith area above2000sq.mts andbuilding height upto 25m (in meters)	Road Side Marginfor Building-unitwith height morethan 25m(in meters)
1	Up to 9	3.0	3.0	–
2	Above 9 and up to 12	4.5	4.5	–
3	Above 12 and up to 18	6.0	6.0	7.5
4	Above 18 and up to 30	6.0	7.5	7.5
5	Above 30	6.0	9.0	9.0

Required Side and Rear Margins

As per the Planning Regulation 13.6.5, required side and rear margin for building-units up to 500sq.mts for Dwelling-1 & 2 are as below

No.	Area of the building unit	Required Rear Margin	Required side margin
1	Up to 150 sq.mts	2.25mts	Not required
2	Above 150 sq.mts and up to 300 sq.mts	2.25mts	1.5mts (Any one side)
3	Above 300 sq.mts and up to 500 sq.mts	2.25mts	3mts (Both sides)

Minimum Margin between Buildings

As per the Planning Regulation 13.6.8, required minimum margin between buildings are as below

No.	Building heights	Required margin (in meters)
1	Up to 15mts	4.5
2	Above 15mts and up to 25mts	6.0
3	Above 25mts and up to 45mts	9.0
4	Above 45mts	12.0

Margin from common plot

As per the Planning Regulation 13.6.9, the required margin from the common plot are as below,

No.	Building height	Required margins (in meters)
1	Up to 25mts	3.0
2	Above 25mts	6.0

Minimum Area of Common Plot

As per the Planning Regulation 13.9.1, the required minimum area of common plot re as below,

No	Use	Area of the Building-unit	Minimum required area of common plot
1	Dwelling-1,2&3	2000sq.mts or more	10% of the area of building unit

Parking

As per the Planning Regulation 13.10, the minimum parking required in dwelling-1,2 & 3 are as below,

No.	Type of use	Minimum parking required	Visitors parking and remarks
1	Dwelling-1,Dwelling-2	1 car parking – for more than 80sq.mts and up to 300 sq.mts ofplinth area per unit.Additional 1 car parking for every100sq.mts additional plinth areaper unit.This shall be permitted within themarginal space	Nil
Dwelling-3	20% of total utilised FSI	10%, of the required parking space shall be provided as visitors parking

Design of parking for car

As per the Planning Regulation 23.2.2,

Minimum dimension of a space provided for parking a car shall be 2.5mts x 5.5mts.

Minimum dimension of a space provided for parking a two-wheeler shall be 0.9mts x 2mts.

Boundary wall/ Compound wall

As per the Planning Regulation 23.1.1,

The height of a boundary wall towards the road‐side shall not exceed 1.5mts from the crown of the adjacent road and 1.8mts from the crown of the adjacent road for all other sides of the building‐unit.

Plinth

As per the Planning Regulation 23.1.6,

The plinth of the habitable area of any building shall be at a minimum height of 0.45mts from the established level of the building-unit.

Minimum clearance height in buildings

As per the Planning Regulation 23.1.8,

The minimum clearance height for Dwelling Units or Commercial Buildings:

a. All habitable spaces shall have minimum height of 2.9mts between finished floor levels.

b. All circulation and service spaces such as veranda, bathroom, washroom, toilet, passage, puja room, store room and stair cabin shall have a minimum clearance height of 2.1mts.

Mezzanine

As per the Planning Regulation 23.1.9,

Mezzanine floor shall have a minimum clear height of 2.1mts which may be allowed in a room at a minimum clear height of 2.1mts from the floor level if the area does not exceed 30% of the area of the enclosed space.

Railing

As per the Planning Regulation 23.1.12,

A parapet/ railing with a minimum height of 1.15mts from the finished floor level shall be provided to ensure safety at all accessible edges of a building such as roof edges, staircase, balcony, floor edges or any large openings and/or fully glazed window.

Staircases

As per the table of Planning Regulation 23.1.14,

No	Use	Height of building (mts)	Staircase
Min. Flight width (mts)	Min. Tread (mm)	Max. Riser (mm)
1	Dwelling-1&2	Three floors uo to 12m	1.0	250	200
2	Dwelling-3	Up to 15m	1.2	250	180
3	Dwelling-3	More than 15 up to 25m	1.5	250	180
4	Dwelling-3	More than 25m	2.0	300	160

Lifts and Elevators

As per the Planning Regulation 23.12

No	Building use	Height of building	Minimum no. of lifts (Whichever is more from column A and B)
A	B
1	Dwelling	Above 15mts	Minimum 1, or	1 Lift per Thirty dwelling units(excluding dwelling units on groundlevel and two upper floors or Hollow plinthand two upper floors)
Above 25mts	Minimum 2, or

Corridors and Passageway

As per the Planning Regulation 24.4, the required width of corridor as per the length of corridor are as below,

Length of corridor (in mts.)	Width of corridor (in mts.) for residential
Up to 6	1.0
Up to 9	1.2
Up to 15	1.2
Above 15 and up to 24	1.5
24 and above	2.0