The Central Government, being of opinion that it is necessary and expedient to do so for the safety of aircraft operations, proposes to make the following certain rules, in exercise of the powers conferred by sub-section (1) and clause (o) and clause (r) of sub-section (2) of section 5 read with section 9A of the Aircraft Act, 1934 (XXII of 1934) (hereinafter referred to as the said Act), and in supersession of the Ministry of Civil Aviation notification number S.O.84(E), dated the 14th January, 2010 published in the Gazette of India, Part II, section 3, sub-section (ii), except as respect things done or omitted to be done before such supersession. The objections or suggestions on the draft S.O. were called from the stakeholders and are considered by the Government to the extent admissible. In the public interest the rules are notified by seeking exemption from putting the rules again in the public domain. Restrictions on constructions, erections, trees, etc.–– (1) No structure shall be constructed or erected, or any tree planted or grown on any land within a radius not exceeding twenty kilometers from the Aerodrome Reference Point of the

civil and defense aerodromes, as specified in Schedule III to Schedule VII, without obtaining a No Objection Certificate for the height clearance, except in cases specified in sub rule (2) of rule 7. (2) No structure shall be constructed or erected, or any tree planted or grown on any land within the areas specified in Schedule I of the civil and defense aerodromes, as listed in Schedule III to Schedule VII, except for essential navigational aids and other installations required for aeronautical purposes. (3) No structure higher than the height specified in Schedule II, shall be constructed or erected and no tree, which is likely to grow or ordinarily grows higher than the height specified in the said Schedule shall be planted on any land within a radius of twenty kilometers from the Aerodrome Reference Point. (4) The level roads and level railway lines within one kilometer of the airport boundary wall shall also be subject to issuance of the No Objection Certificate.

Extract from ICAO Annex 14 (CHAPTER 4)

OBSTACLE RESTRICTION AND REMOVAL

Note 1 : —The objectives of the specifications in this chapter are to define the airspace around aerodromes to be maintained free from obstacles so as to permit the intended aeroplane operations at the aerodromes to be conducted safely and to prevent the aerodromes from becoming unusable by the growth of obstacles around the aerodromes. This is achieved by establishing a series of obstacle limitation surfaces that define the limits to which objects may project into the airspace.

Note 2 : — Objects which penetrate the obstacle limitation surfaces contained in this chapter may in certain circumstances cause an increase in the obstacle clearance altitude/height for an instrument approach procedure or any associated visual circling procedure. Criteria for evaluating obstacles are contained in Procedures for Air Navigation Services — Aircraft Operations (PANS-OPS) (Doc 8168).

Annex 14 also goes on to state:
4.2.11 Recommendation : New objects or extensions of existing objects should not be permitted above the approach surface beyond 3 000 m from the inner edge, the conical surface or inner horizontal surface except when, in the opinion of the appropriate authority, the object would be shielded by an existing immovable object, or after Aeronautical study it is determined that the object would not adversely affect the safety or significantly affect the regularity of operations of aeroplanes. The previous paragraph lets us mitigate a new object with an aeronautical study which would include Pans-Ops.

Global Coordinates conducts ‘Permissible Height Analysis’ for buildings based on GSR 751 (E)
and ICAO Annexture 14 criteria for Obstacle Restriction.