Airport Height Limit API: buildable height near an airport

Example

Request

curl -X POST https://verified.realestate/api/v1/tools/airport_height \
  -H "Authorization: Bearer $LANDLENS_KEY" \
  -H "Content-Type: application/json" \
  -d '{"lat":12.9675,"lng":80.15,"proposed_height_m":30}'

Responsereal answer

{
  "ok": true,
  "status": "ok",
  "data": {
    "found": true,
    "in_restriction_zone": true,
    "max_allowed_m": 46,
    "permissible_top_elevation_m": 46,
    "ground_elevation_m": 24.9,
    "ground_source": "aai_certificates",
    "ground_basis": "the middle of the ground levels surveyed for the 5 nearest AAI height clearances, within 960 m, which run from 18.8 to 26.5 m",
    "buildable_height_m": 21.1,
    "governing_source": "AAI CCZM",
    "airport": "Chennai",
    "all_limits": [{"source": "AAI CCZM", "max_height_m": 46, "airport": "Chennai"}],
    "proposed_height_m": 30,
    "compliant": false,
    "noc_required": true,
    "noc_reason": "The proposed height is above the height the zoning map clears here.",
    "approx_floors": 7
  },
  "credits_charged": 0
}

A real answer from the API for a point in Pallavaram, near Chennai airport, with the reading note left out.

What it returns

One call, one answer. Quote buildable_height_m, never the top elevation, as the height.

Field	What it holds
`in_restriction_zone`	Whether the point lies in a mapped airport height zone.
`permissible_top_elevation_m`	The governing limit, in metres above mean sea level. max_allowed_m carries the same figure under its older name.
`ground_elevation_m, ground_source, ground_basis`	The ground level at the site, whether it came from AAI certificates or the terrain model, and how.
`buildable_height_m, approx_floors`	The height that can be built above ground, and the floors that allows at about 3 m a floor.
`governing_source, airport, all_limits[]`	Which map set the limit, the aerodrome, and every limit read.
`proposed_height_m, compliant`	The height you sent and whether it fits under the buildable height.
`noc_required, noc_reason`	Whether an AAI NOC is needed first, and the reason in words.
`no_permitted_top, top_below_ground`	Present when the map clears no height at all at this point.
`cmda_area`	Whether the point is in the CMDA area, where CMDA asks for an AAI NOC on buildings of 30.5 m or more.

Inputs

The JSON body of the POST is the arguments. Send the plot's latitude and longitude, and the planned height if there is one.

Argument	Type	What to send
`lat`required	number
`lng`required	number
`proposed_height_m`	number	The planned building height above ground, in metres, to test against the limit.

Code

Set LANDLENS_KEY to your key. In an AI app, connect https://verified.realestate/mcp once and ask in plain words instead. In Postman, download this API's collection, import it (File, Import) and set apiKey.

curl -X POST https://verified.realestate/api/v1/tools/airport_height \
  -H "Authorization: Bearer $LANDLENS_KEY" \
  -H "Content-Type: application/json" \
  -d '{"lat":12.9675,"lng":80.15,"proposed_height_m":30}'

import os, requests

r = requests.post(
    "https://verified.realestate/api/v1/tools/airport_height",
    headers={"Authorization": f"Bearer {os.environ['LANDLENS_KEY']}"},
    json={
        "lat": 12.9675,
        "lng": 80.15,
        "proposed_height_m": 30
    },
    timeout=20,
)
body = r.json()
print(body["status"], body["credits_charged"], body["data"])

const res = await fetch("https://verified.realestate/api/v1/tools/airport_height", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.LANDLENS_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "lat": 12.9675,
    "lng": 80.15,
    "proposed_height_m": 30
  }),
});
const body = await res.json();
console.log(body.status, body.credits_charged, body.data);

How tall can I build at 12.9675, 80.1500 near Chennai airport? Will a 30 m building need an AAI NOC?

Your AI reads the airport zoning maps at the point and works out the buildable height. It is free.

Responses

Every answer has the same envelope. What status can say for this call:

status	What it means
`ok`	The point was read, inside a zone or outside every zone.
`not_found`	The point is outside Tamil Nadu, or lat and lng were zero. Nothing is charged.
`invalid_args`	lat or lng was missing. Nothing ran.
`free_limit_reached`	The account has used its free calls for the hour or the day. retry_after says how many seconds to wait; paid calls keep working.

Where the data comes from

Register

Two maps of permissible top elevation around aerodromes: the state GIS airport NOC layer and the Airports Authority of India's colour coded zoning maps. Ground level comes from the surveyed site levels on nearby AAI height clearances, or from a 90 m terrain model.

Coverage

Points anywhere in Tamil Nadu. Inside a mapped zone the limit is read; outside every zone the answer says so. A point outside the state is refused.

How current

The zoning maps change only when the Authority revises them. The height clearances used for ground level are refreshed about once a quarter.

How we read it

Both maps are read at the point and the lower limit governs. A limit is a top elevation above sea level, not a height, so the ground is subtracted: the middle of the ground levels surveyed for the nearest AAI clearances when enough agree within 1 km, otherwise the terrain model. The square AAI colours "NOC to be obtained" clears no height at all and is reported that way.

Who uses it

Architects and developers

Know the buildable height near an airport before drawing the section, and whether the plan needs an AAI NOC first.

Buyers of land near airports

See how many floors the zoning map allows on a plot before paying for it.

Planning tools

Add the airport height limit to a feasibility calculator from the plot's map pin.

Limits and good practice

The limit is a top elevation above sea level. The buildable height depends on the ground level, which is read, not surveyed at your plot.
Under the zoning map the local authority approves up to the mapped height; above it, or in a square marked for it, an AAI NOC is needed. Not every building near an airport needs one.
CMDA's 30.5 m rule is its own practice, applied only in the CMDA area.
This is the map's limit, not a clearance. For clearances the Authority has actually issued nearby, use airport_noc_issued.

Pricing

Free

The airport height check costs nothing. Free calls have their own allowance per hour and per day, counted across every key and connected app on the account. Credits come from the same LandLens wallet as the chat and the minis. How billing works.

Calling at volume?

Free calls have an hourly and daily allowance. For more than that, or a platform built on these registers, we set up limits and a plan to match.

WhatsApp 99961 29996

Questions

Is there an API for airport height restrictions in India?

For Tamil Nadu, yes. Send a point and get the permissible top elevation from the airport zoning maps, the ground level and the buildable height above it.

Why is the buildable height less than the limit?

The maps give a top elevation above mean sea level. The building can rise only from the ground at the site, so the ground level is subtracted.

Do I need an AAI NOC?

Send proposed_height_m. noc_required and noc_reason say whether the plan needs one and why: above the map's height, in a square marked for a NOC, or under CMDA's 30.5 m practice.

How much does it cost?

It costs nothing, within the account's free call allowance.