Tamilnadu municipality byelaws and building rules (1972)
b. For the construction, reconstruction, addition or alteration of a building the permission will not be granted if the clearance between the building and the aerial lines is less than.
1.5m for low tension and 1.75 m for high tension lines measured horizontally incase of accessible portions of the buildings
1.25m for low and high tension lines measured horizontally incase of inaccessible portions of the buildings.
2.5m for portions of the buildings not accessible to the portions measured
2. Space of buildings
Where the street at anyplace is less than 3.75m in width, the building should not be
built within 2m from the center point of the street.
No other structure than the steps, fence is permitted in the space between the building and edge of the street.
The doors and window shutters should not open Outward Street where the street is
3.75m or more width and the buildings is built along with edge of the street.
3. Dimensions of rooms
A height of an average is not less than 2.75 m and 2.1m at any point measured from top surface of the floor to the underside of the roof.
A clear superficial area is not less than 7.5m2
A width is not less than 2.5m
Bathroom area is 1.8m2 (1.52 x 1.2m)
The water closet or toilet shall be 1 m2 (1.2 x 0.9m)
The bath cum water closet shall be 2.7m2 (1.82 x 1.52m)
4. Ventilation of buildings
Every room intended or used for human habitation (human activites) should have windows and ventilators
The area of ventilation should not be less than 1/8 floor area or carpet area
Every domestic building constructed for human habitation should have at least one side abutting for a length of not less than 2.5m on an open space either internal/external. Such open space shall not be less than 1.75m in width.
Every open space either internal or external should open to sky no construction is allowed in the open space area.
For bath and toilets the area of windows or ventilator should not be less than
1 sqm = 10.75 sq.ft
0.5 sqm = 5.38 sq.ft [3' x 2' = 6 sq.ft]
5. Minimum width
The doorways, windows or passage should have a minimum width of 1m. The door of kitchen, bath and toilet should not be less than 0.6m clear width.
Chimneys, flush and sanitary appliances or convenience are to be provided properly in the building.
a. Width of the stair
The clear width of the stair excluding hand rail shall not be less 500 mm.
b. Head room [Height from floor to roof]
The headroom should be at least 2.1m measured perpendicular from the nosing (projection on step)
c. Tread and Riser
The riser shall not be more than 175mm and the tread shall not be less than
250 mm. the sum of two risers and the tread shall not be less than 600mm and not more than 625mm. in one flight should be not be any variation in rise / tread. No stairs should be permitted to cut across a window.
The height between the landings shall not be more than 3.75 m
The handrails shall be placed at the height not less than 750mm and not than 1000mm above the projection of step.
The passage giving access to the staircase width shall not be less than the stair width. In the passage gives access to more than 1 stair its minimum width shall be equal to the width of the stair +1.5 of total width of the remaining stair width.
Passage width should not be less than stair width. If the passage gives access to the more one stair. Its minimum width shall be equal to width of the stair. The State and Central government building are exempted from these rules.