Environmental Impact Assessment Ordinance

Technical Memorandum

Annex 5

ANNEX 5 : CRITERIA FOR EVALUATING NOISE IMPACT

Summary of Noise Criteria

Table 1 gives a summary of criteria for evaluating noise impact of designated projects. The Director would apply these criteria in the following manner:

  1. noise criteria laid down in relevant technical memoranda issued under the Noise Control Ordinance must be met;

  2. noise criteria, as listed in Table 1A, for planning and design of designated projects, shall be met, unless it can be demonstrated by the applicant that the residual noise impact would not have long term, serious adverse implications for the environment and community. The Director would normally use the criteria listed in Section 4.4.3 of this technical memorandum to evaluate whether there would be long term, serious adverse environmental implications;

  3. noise criteria, as listed in Table 1B, for construction or decommissioning of designated projects, shall be met as far as practicable. All practicable mitigation measures shall be exhausted and the residual impacts shall be minimised;

  4. for noise matters not fully listed in the annex, the criteria for evaluating such noise impacts shall be determined on a case by case basis;

  5. wherever such terms exist in the relevant technical memoranda issued under the Noise Control Ordinance, the definitions of such terms shall apply to this technical memorandum.

Table 1 : A Summary of Noise Criteria

Table 1A

Noise Standards for Planning Purposes

Noise
Sources


Noise
Standards


Common Uses

Aircraft Noise
(Noise Exposure
Forecast:NEF)

Helicopter
Noise
Lmax
dB(A)

0700 to
1900 Hours

Road Traffic
Noise

Peak Hour
Traffic
L10
(1 hour)
dB(A)

Rail
Noise		 Fixed Noise
Sources
Kai Tak
Airport		 New Chek
Lap Kok
Airport
All domestic premises including temporary housing accommodation 30 25 85 70 (a)
(See Note 3)
The appropriate Acceptable Noise Levels shown in Table 3 of the Technical Memorandum for the Assessment of Noise from Places Other than Domestic Premises, Public Places or Construction Sites and

(b) Lmax (2300 - 0700 hours) = 85dB(A)

(a)
5 dB(A) below the appropriate Acceptable Noise Levels (ANL) shown in Table 3 of the Technical Memorandum for the Assessment of Noise from Places Other than Domestic Premises, Public Places or Construction Sites, or

(b) the prevailing background noise levels (For quiet areas with level 5 dB(A) below the ANL)

Hotel and hostels 30 25 85 70
Offices 30 30 90 70
Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required 30 25 85 65
Places of public Worship and courts of law 30 25 85 65
Hospitals, clinics, convalescences and homes for the aged, diagnostic rooms, wards 30 25 85 55

Notes:

  1. The above standards apply to uses which rely on opened windows for ventilation

  2. The above standards should be viewed as the maximum permissible noise levels assessed at 1 m from the external facade

  3. Rail noise is under the control of the Noise Control Ordinance and shall comply with the Acceptable Noise Levels laid down in the Technical Memorandum for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites

Table 1B

Noise Standards for Daytime Construction Activities

Noise Sources



Noise

Standards


Uses		 0700 to 1900
hours on any
day not being a
Sunday or
general holiday



Leq (30 mins)
dB(A)		 1900 to 0700
hours or any
time on
Sundays or
general holiday
  • All domestic premises including temporary housing accommodation
75 (See Note 3)
  • Hotels and hostels
75
  • Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required
70

65
(During examinations)



Notes:

  1. The above standards apply to uses which rely on opened windows for ventilation.

  2. The above standards shall be viewed as the maximum permissible noise levels assessed at 1 m from the external facade.

  3. The criteria laid down in the relevent technical memoranda under the Noise Control Ordinance for designated areas and construction works other than percussive piling may be used for planning purpose. A Construction Noise Permit (CNP) shall be required for the carrying out of the construction work during the period.

Table 2 : Suitable Window Types for Noise Insulation


Suitable window type when the estimated noise level will exceed the relevant standard by B value.

window
types

Exceedance
over standard

Noise source

I II III
Rail Traffic B < 5 5 < B < 10 B > 10
Road Traffic B < 10 10 < B < 15 B > 15
Aircraft - B < 10 B > 10
Helicopter B < 5 5 < B < 10 B > 10
NOISE INSULATION PERFORMANCE AND WINDOW TYPES

  1. - openable well-gasketted window, 6mm pane, or transmission loss (TL) of 28dB or above in 250 Hz octave-band and sound transmission class (STC) 31 or above

  2. - openable well-gasketted window, 8mm pane, or TL of 32 dB or above in 250 Hz octave-band and STC 34 or above

  3. - openable well-gasketted windows, 12 mm laminated pane, or TL of 33 dB or above in 250 Hz octave-band and STC 38 or above

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