CMDA Chennai

Certain structures are permitted on terrace floors as part of approved architectural features under prescribed building norms.

For both NHRB & HRB buildings, AC plant areas and up to two toilets per block may be permitted on the terrace floor with architectural features up to 3.00 m height. The parapet wall portion above the allowable 1.5 m height must remain non-continuous, with solid portions not exceeding 50% of the surface area.

These provisions help accommodate essential building utilities while maintaining safety, ventilation, and compliance standards.

Permanent compound walls are not permitted within street alignment or approved road widening portions. Compound walls must be constructed only after leaving the designated area as per the approved plan.

The land reserved for road widening may, however, be utilized for landscaping with temporary grill or barbed wire fencing, with or without a dwarf wall not exceeding 0.60 m height, applicable for both HRB & NHRB buildings.

These regulations help preserve land for future public infrastructure and planned urban development.

Setback spaces and minimum distance between building blocks are essential for ensuring ventilation, safety, accessibility, and planned urban development.

For NHRB buildings, limited setback reductions are permitted while maintaining the prescribed minimum clearances. In HRB buildings, setback reductions are allowed up to specified limits based on building height, subject to maintaining the required minimum setback standards.

These norms help ensure proper spacing between structures while preserving safety and regulatory compliance.

Changes in the location or orientation of an Overhead Tank (OHT) are permissible under approved building norms. However, in cases where the size of the OHT is increased, applicable development charges shall be collected as per regulations.

Any increase in OHT size will be treated under non-FSI area considerations, and additional charges may apply accordingly.

These provisions help ensure proper utility planning while maintaining compliance with development regulations.

Certain utility structures and access facilities are permitted within setback areas under prescribed building norms, provided they do not affect ventilation, parking, or movement requirements.

For both NHRB & HRB buildings, features such as access steps, ramps, closed wells, water & sewage treatment plants, generators, and box-type transformers may be allowed in setback areas subject to maintaining the required driveway width and approved parking provisions.

These regulations ensure functional infrastructure while maintaining safety, accessibility, and compliance standards.

Permissible building height variations are allowed under prescribed norms, provided they do not affect safety standards or result in additional floors.

For NHRB buildings, height may be increased up to 3% of the approved height within specified limits. In the case of HRB buildings, height variation up to 5% is permitted with corresponding setback provisions on a pro-rata basis.

All height variations must remain within the limits prescribed by competent aviation authorities such as AAI / IAF.

These provisions ensure flexibility in development while maintaining structural safety and regulatory compliance.

Open Space Reservation (OSR) land is reserved for public purposes and regulated under approved planning norms.

As the OSR space is vested with the competent authority or local body, no permanent structure shall be constructed or erected on such land. These spaces must be maintained and utilized strictly in accordance with approved regulations and public-use requirements.

Protecting OSR land supports sustainable urban planning, environmental balance, and community welfare.

Interconnection between flats is permitted for both HRB & NHRB buildings, provided the mandatory parking requirements are fully satisfied.

Such interconnections should not affect the approved parking provisions or circulation spaces within the premises. However, interconnection between flats is not permitted in affordable housing projects.

These regulations help ensure proper planning compliance while maintaining essential infrastructure and accessibility standards.

Rain Water Harvesting systems are mandatory for all developments as part of sustainable and responsible urban planning practices.

Proper rainwater harvesting provisions help conserve water resources, improve groundwater recharge, and support long-term environmental sustainability. Installation of these systems is an essential requirement for obtaining a Completion Certificate (CC).

Implementing rainwater harvesting contributes to a greener and water-secure future for urban communities.

Column changes or addition of new columns in stilt floor areas are permitted under prescribed building norms, subject to maintaining essential movement and parking requirements.

For both NHRB & HRB buildings, a minimum 3.00 m driveway must be maintained to ensure smooth vehicular movement. Any modifications should not affect the approved parking capacity or compromise accessibility within the premises.

These provisions help accommodate practical structural adjustments while ensuring safe and efficient usage of parking spaces.