Sep 17, 2013

Rules for ’special’ residential buildings


The rules have become more rational in regard to parameters such as plot extent, frontage, maximum permissible height and setback space

Good tidings: The new rules have brought cheers to those constructing Special residential buildings.
The Development Regulations of the Second Master Plan for Chennai Metropolitan Area must have brought cheers to those involved in the construction of Special Buildings for residential use as it carries many concessions and relaxations to the existing rules.
The new regulations define ‘Special buildings’ as (a) residential or commercial buildings with more than 2 floors or b) residential buildings with more than 6 dwelling units or c) commercial buildings exceeding 300 sq.m of floor area.
Even though the minimum required width of road for Special buildings is retained as 10m, they would be permitted for residential use on 9m width as well with certain restrictions.
There is no change in the maximum permissible FSI of 1.5. However a large number of things have been excluded from the calculation.
The area of balcony to an extent of 5% of each dwelling unit in the case of residential buildings and area for building services and incidental structures (such as office room for the Residents association, toilets for drivers, gymnasium, and rooms for electrical and air conditioning services etc.) to a maximum of 10% of the total floor area are excluded from FSI calculations.
Further to encourage participation from private sector in providing housing to lower income groups, incentive in the form of additional 0.25 FSI is considered in residential developments with dwelling units not exceeding 45 sq.m of floor area each.
Special Buildings (Residential)
The rules have become more rational with relationship established between many parameters such as plot extent, plot frontage, maximum permissible height and setbacks required. There are no limits with regard to the number of dwelling units that can be built on 10m wide roads provided the qualifying parameters of minimum plot extent of 300 sq.m and minimum plot frontage of 9 m are met. However on such plots, buildings with G+1 or Stilt+2 floors with a maximum height of 9m alone will be permitted.
Plots having a minimum extent of 450 sq.m and with minimum plot frontage of 12m are eligible for buildings with G+2 or Still+3 floors subject to a maximum height of 12m. Properties with a minimum plot frontage of 15m will qualify for buildings with G+3 or Stilt+ 4 floors with the maximum height of 15.25m. In other words, plots having a greater extent and frontage alone qualify for taller buildings.
The front set back requirement has not undergone any change and the same is governed by the width of the abutting road. It varies from a minimum of 3.5m to a maximum of 6m.
There has been an appreciable change in the side setback requirement and the same is governed by the height of building proposed. It can be a minimum of 1.5m for 9m tall buildings, 3.5m for 12m tall buildings and 4.0m for 15.25m tall buildings. (As per the earlier rules, one third the height of building is to be left as side setback.) Similarly rear set back also is dependent on the height of building proposed and in effect it is the same as side setback. This was earlier dependent on the depth of the plot. It is also observed that plot coverage is not a factor for consideration in Special buildings.
With the reduction in side setback requirements, though it will be possible to achieve the permissible FSI in most cases the buildings would become closer to each other.
With cantilevered balconies of 1.2m width now permissible ( against 1.0 M earlier) they would become even closer. With the parking requirements becoming more stringent, most special buildings in future would have to be built on stilts to accommodate parking in ground floor.
Special Buildings on 9 metre roads
Special buildings are now permissible on roads having a minimum width of 9m with certain restrictions on maximum number of dwelling units and height. While the maximum dwelling units permissible is related to the plot extent, the maximum height permissible is related to the plot extent and the plot frontage. The prerequisites for a Special building on 9m wide road are the minimum plot extent of 200 sq.m and minimum plot frontage of 9m.
On such plots, buildings with G+2 floors or Stilt+3 floors with a maximum height of 12m is permissible. As per earlier rules, one had to wait for 3 years to construct the second floor.
The maximum number of dwelling units permissible is restricted to 6 in such plots.
Plots having a minimum extent of 300 sq.m and 450 sq.m are eligible for 8 dwelling units and on such plots the permissible height depends on the plot frontage. Plots with 300 sq.m extent and 9m plot frontage are eligible for buildings with G+1 or Stilt+2 floors with a maximum height of 9 m. On plots with 450 sq.m extent, if the plot frontage is 12m, buildings with G+2 or Stilt+3 floors with a maximum height of 12 m is allowable.
0For the same plot if the frontage is 15m, then buildings with G+3 or Stilt+4 floors subject to a maximum of 15.25m is permissible.
If the minimum extent of a plot is 660 sq.m, it qualifies for a maximum of 12 dwelling units. The maximum permissible height depends on the plot frontage. If the frontage is 15m, then buildings with G+2 of Stilt+3 with a maximum height of 12m is allowable. However on plots having a frontage of 18m, buildings of G+3 of Stilt+4 with a maximum height of 15.25m are permissible. Plots having a minimum extent of 1100 sq.m and frontage of 15m are eligible for buildings with G+3 or Stillt+4 floors subject to a maximum height of 15.25m. On such plots there are no restrictions on the maximum number of dwelling units.
The setback requirements special buildings on 9m wide roads are the same as that of special buildings on 10m wide roads. Earlier, FSI of 1.5 could not be achieved on most residential plots due to height restrictions. Henceforth it would be possible to achieve the FSI and by virtue of the same the housing stock could increase.
-The Hindu