High rises in Bengaluru: Here’s what you need to know!

Aviation safety and high rises in Bengaluru: Here's some knowledge no property dealer would want to share with you!

The High Court of Karnataka has noted in the recent hearing of Chalet Hotels v/s HAL case that the investors who have put their money into Raheja Vivarea would have to sacrifice their interest if the court decides that the height of Raheja Vivarea cannot be allowed beyond 45 metres.

This brings us to the question: What exactly went wrong in this case? And what is that you – the property buyer – have to keep in mind?

There have been cases of wrong height certificates submitted which gave the builders permission for extra floors in high rises illegally. Pic: Satarupa Bhattacharya

Most of us are not aware of the zoning and safety rules for high rises. Raheja Vivarea story revolves around submission of wrong ground elevation (height Above Mean Sea Level – AMSL) to Hindustan Aeronautics Limited, and the cancellation of No-objection Certificate for Raheja Vivarea by HAL when the irregularity was discovered. Chalet Hotels, the builders of Raheja Vivarea, have sued HAL now, for cancelling the NOC, and the construction activities have come to a halt. The case is pending in High Court.

What is height above mean sea level?

Height Above Mean Sea Level (AMSL) is the elevation of the ground from average sea level. Since it is not possible to measure the sea level accurately, average height is taken into consideration.

For aircraft safety, a minimum of 500 feet (150.40 metres) vertical separation from any object on the ground is required to be maintained. Therefore under section 9 (A) of Aircraft Act 1934, Ministry of Civil Aviation has imposed height restriction on construction or erection of any vertical structure around every aerodrome. The height restriction eases as you go farther from airports.

Buildings, statues, chimneys, transmission lines, masts and other vertical structures need height clearance. This clearance ensures aviation safety and the safety of the buildings or structures.

In case of Raheja Vivarea, wrong height, which was less than the actual height above mean sea level, was submitted to HAL, to ensure HAL grants permission for the extra floors, which were violative of the norms. And if you thought Raheja Vivarea is the only such case, no. There are many other builders who are on the same boat — some discovered, many undiscovered.

Who can measure the height?

Ministry of Civil Aviation Notification no. SO84, dated January 14th, 2010 mandates all vertical structures near airport to procure a height certificate from an agency/ civil engineer certified from government body. This agency measures height of the ground elevation and provides a certificate. This certificate is required to be authenticated from local authority — usually the Town Planning engineers of BDA/BBMP who authenticate the certificates.

Officials of Airport Authority of India say that any civil engineer appointed by Municipal Corporation or local authority or a civil engineer professor certified by government can provide elevation certificate.

According to ex-general manager of AAI and Chairman of NOC committee A N Vishwanath, who now works as the supervisor at Government Flying Training School, Civil Engineering professors working for colleges like Ambedkar Institute of Technology and BMS College of Engineering are qualified to provide elevation certificates.

However, for the general knowledge and verification purposes, anyone can measure the height with the help of Global Positioning System. Free online tools are also available where you just have to pinpoint a location and the height above mean sea level can be seen. Architects make use of Theodolite GPS instrument to check the height.

Why should you care about height?

There are three zones that have different height limits for each, around each airport. They are:

  • Inner Horizontal Surface (5 km radius from Aerodrome Reference Point – ARP)

  • Outer Conical Surface (ranges between 5km to 20 km radius from ARP)

  • Outer Transitional Surface (Ranges from 20 km to 56 km radius from ARP)

If your building lies within these zones, you need to care about the height of the building. Apart from aircraft’s safety, your safety too is at stake. How?

Whenever flights or aircrafts do not get a clear runway to land, they hover above the airport vicinity, till the runway is clear. As a plane descends, the height between the structures below and the plane lowers, thus increasing the possibility of it hitting any object that has not adhered to height norms. This would prove dangerous for the aircraft, the building and its inhabitants, and the surroundings.

Defence aerodromes are known to run trials with different defence aircrafts, and conduct trainings for the army. Their activities are classified and not open to public, but certainly there is a risk for the aircraft used as well as the structures around. Therefore there is even requirement of undertakings to be given by the builder on not emitting smoke, not complaining about noise etc, before getting NOC.

How much height around each runway?

Section 9(A) of Aircraft Act 1934 says that height restriction depends on the type of runway and the location of structure to be built. Each runway has its own no-construction periphery, inner horizontal surface, conical surface and outer horizontal surface to be maintained.

Bangalore has four airports — Hindustan Aeronautical Limited, Kempegowda International Airport Limited  (KIAL – formerly known as BIAL), Government Flying Training School (GFTS) Jakkur and Yelahanka Defence Aerodrome.

Zoning maps for height regulation of each airport are available with the concerned airports. AAI has also planned to distribute a colour-coded zoning map for each airport. However, following paragraphs will give you understanding of how the height in such zones is measured.

1. No-construction zone

Apart from height above sea level, height restriction for any vertical structure or building varies for different runways. There are four types of runways — Code 1, 2, 3, and 4. Code 3 and Code 4 runways have stricter norms to be followed. Each runway will have its own limits to follow.

No-construction is allowed along the sides of runways with code no. 1 and 2, up to 40 metres from the central of line of the runway. From the end of the runway, from the area where the aircraft takes off or lands, a distance of 300 metres should be maintained as no-construction zone. Government Flying Training Institute at Jakkur makes use of Code 2 runway.

Code 3 and 4 runways have stricter norms to adhere to. Along the sides of the runway, 150 metres from the central line of the runway is maintained as no-construction zone. From the ends of the runway, where aircraft lands or takes off, no-construction zone is maintained from 300 metres from the central line of the runway. KIAL uses this kind of runway.

Height restriction for structures that fall within the approach path of aeroplanes — that is, take off and landing path — is rigid. Here the height is restricted to 2% of the distance from the edge of the runway.

2. Inner horizontal surface

Aircraft Act 1934 defines the area within 5 km radius radius from Aerodrome Reference Point (ARP) as inner horizontal surface. This zone, as per section 9(a) of Aircraft Act 1934 restricts construction of any vertical structures to maximum 45 metres. Maximum height allowed in this area above ground level is the height Above Mean Sea Level at the reference point and 45 metres. The elevation of ARP differs for every airport.

3. Outer conical surface

The area beyond inner horizontal surface i.e from 5 km up to 20 km radius from the Aerodrome Reference Point is called as Outer Conical Surface. Here, the height restriction is eased by 1:20 ratio — i.e., after 5 km away from the runway, for every 20 meters, a building can go 1 metre high.

However, no building’s height can exceed a certain limit in this zone — for defence aerodromes, this height is 150 metres. by the bylaw for that particular airport. (BDA’s RMP for HAL airport, BIAAPA rules for KIAL, BBMP bylaws for Jakkur and Yelahanka, etc) — depending upon its runway code.

For example, the buildings that lie on the outer conical surface of HAL airport, as per RMP-2015, can go upto 100 metres – not more than that.

4. Outer transitional surface

Outer transitional surface spreads from 20 km to 56 km. Even when planning authorities like BIAAPA or BDA don’t mark it on their zoning maps, the Aircraft Act considers buildings with height above 150 metres to 300 metres as an obstacle.

Therefore all such structures are mandated to procure NOC from Airport authority of India. Similarly, the height criteria is imposed on objects having height above 300 metres in an area beyond 56 km from the aerodrome.

Yelahanka Defence Aerodrome requires NOC within 9.26km. Aircraft Act gives liberty to the Defence Aerodromes to set their own norms for height restriction. When we contacted Yelahanka Defence Aerodrome, they said that the NOC is required for buildings within 5 nautical miles radius, which is equal to 9.26 km. No further details could be sought.

NOC from Defence aerodromes

HAL, which was a civil airport earlier, is now a defence airport, falling under the Indian Air Force. However, the rules for NOC are the same as the rules for NOC from International Airport, which is governed by Aircraft Act 1934.

Yelahanka aerodrome and Government Flying Training School are also governed by the same rule, but the Local Flying Area for these are different from that of HAL. The head of thes aerodromes is authorised to issue NOCs.

HAL and Yelahanka airport have been issuing NOC since the time of their establishment. GFTS was established in the year 1949. GFTS Aerodrome Supervisor, A N Vishwanatha, says: “Nobody paid attention to the flying institute’s safety till last year (2012). Director of Airport Traffic Management, in 2013, issued an order that high rise buildings near GFTS should also procure NOC from GFTS in order to safeguard aerodrome safety.”

Accordingly, height restriction of 40 metres is adhered within 5 km radius of the aerodrome. GFTS started issuing NOC from the last year, January 1st, 2013. However very few people were aware of the new rule. High rises continued to come up obstructing the path of flights. This led to the publication of a notice asking all the builders to procure NOC from GFTS, in January 2014.

Click here to read the rules for NOC from Defence Aerodromes.

Owners to pay if violations are proved

Without obtaining NOC, no builder can start the construction of a high rise building. If the building is found in violation of rules, the NOC clearly says the owner has to bear the cost.

But, once the construction is over and ownership of the building is transferred into the hands of the residents staying there, the residents have to bear the cost of demolition for a fault of the builder.

It can also lead to a long legal battle between the builder and the resident who invested in the demolished structure, for the refund of the money, with no guarantee of refund whatsoever. It’s better to be safe than sorry later – check the legalities of height clearance before purchasing a property.

The concerned airport near the building will be responsible for taking action against the height violators.

No butcheries near aerodromes

The BBMP building bye laws and Ministry of Civil Aviation rules restrict establishment of slaughter houses, butcheries or even garbage dumping activities within a radius of 10 km from ARP, as such places attract high-flying birds like eagles, hawks etc.

How do you check for violations?

National Building Code of India defines a high rise as height above 15 metre, while RMP 2015 defines it as height above 24 metres. (The change in definition of height is a another mystery, already covered in detail by Citizen Matters.)

However, BBMP considers all buildings above 15 metres as high rises. It is always better to take NOC from airports, for all buildings higher than 15 metres.

Each floor is approximately equal to three metres. Therefore if you are staying in, or planning to buy, an apartment in a high rise building, just try the easy math to detect whether there is any possibility of height violation, for the floor that you have your eye on.

  • Multiply the number of floors by 3 to get approximate building height. If the building has 15 floors, multiply it by 3, the answer will be 45 metres.

  • Check google map for the distance of the place from the airports.

  • Now compare the results with the zonal height restrictions for each airport, to figure out whether the building is in violation or not.

  • Remember that every high rise structure — especially the ones near Yelahanka and Jakkur — might need multiple NOCs, as the location might lie within various circles of various airports, and might need clearances.

Practical examples:

Your 18-floor high rise is within 4 kms of HAL airport or Yelahanka Aerodrome. You can start by asking the questions: What is the height of the building? What is the height AMSL for this place? Whether the height projected is correct? What are the rules for the nearest airport? How high is safe? etc.

If your high rise is located within 20 kilometres of HAL airport, the high rise cannot go beyond 152 metres — according to Airport bylaws. Try doing this math for the high rises in Bangalore!

When you have doubts, for accurate details, RTI is the only way out, if you are keen on investing safely on a high rise.

To check the Ministry of Civil Aviation Notification, click here.

To read the procedure to procure NOC, click here.

Online system for applying for NOC, click here.

Most property dealers wouldn’t know these rules; those who know wouldn’t share it with you. So always do your research before investing. Better be safe, than sorry later!

Related Articles

Nod to Raheja Viverea revoked: Chalet Hotel sues HAL
HC raps HAL for delayed action on height violation
Aviation safety norms: Developer vs. HAL dispute intensifies in court


  1. Tsrif Tsal says:

    Superb Article !! 18 floor high rise within 4 km of aerodrome, where have I seen it ?? 😉

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Similar Story

Chennai’s new airport: On-ground realities differ from what’s on paper

There are many inconsistencies in the various documents and reports prepared to facilitate the greenfield airport project in Parandur.

It's close to 700 days since residents of Parandur and surrounding villages started their protest against the government’s decision to establish a new greenfield airport at a site in that area in the outskirts of Chennai. People living there allege that authorities did not consult them or listen to their grievances before proceeding with the project.  Just after the Lok Sabha elections, the government sent a notification announcing land acquisition for the proposed airport. Recent news reports indicate that some villagers have decided to relocate to neighbouring Andhra Pradesh, as their livelihoods are threatened. The impact on the lives and…

Similar Story

Taking flight: Does Chennai need a second airport and at what cost?

Civic and environmental activists question the feasibility of the greenfield airport in Parandur and suggest expansion of Chennai airport.

Ten lakes, two streams, 3,500 acres of agricultural land, 1,005 families and hundreds of plant and animal species — these are all under threat because of one development project. There has been a considerable buzz regarding the Chennai Greenfield Airport set to come up in Parandur on the outskirts of the city. But, not all the noise is positive. Villagers in Parandur have been protesting for almost 700 days and some have even boycotted the Lok Sabha 2024 elections, asking the government to withdraw the project.   Yet, work is steadily progressing on the greenfield airport and the government is…