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 (Cap. 400) 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 exceeding the criteria as listed in Table 1A would not have long term adverse implications for the environment and community. The Director would use the criteria listed in Section 4.4.3 (a)(ii)-(v), (x) and Section 4.4.3 (b) of this technical memorandum to evaluate whether there would be long term, adverse environmental noise 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 are minimized;
  4. for noise matters not fully listed in this 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
  • All domestic premises
  • Temporary housing accommodation
  • Hostels
  • Convalescent homes, and
  • Homes for the aged







25







85

 







70

 

The appropriate Acceptable Noise Levels shown in the Technical Memorandum for the Assessment of Noise from Places Other than Domestic Premises, Public Places or Construction Sites

(a)
5 dB(A) below the appropriate Acceptable Noise Levels (ANL) shown in 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)
  • Educational institutions (including kindergartens and nurseries)
  • Places of public worship, and
  • Courts of law

 

 

25

 

 

 

85

 

 

 

65

 
  • Hospitals and medical clinics

25

85

55

Notes:

  1. The above standards, or equivalent, apply to uses which rely on opened windows for ventilation and are assessed at 1m from the external façade.

Table 1B

Noise Standards for Daytime Construction Activities

 

 

Uses

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

Leq (30 mins)
dB(A)
  • All domestic premises,
  • Temporary housing accommodation,
  • Hostels
  • Convalescent homes, and
  • Homes for the aged

75
  • Places of public worship,
  • Courts of law, and
  • Hospitals and medical clinics

70
  • Educational institutions (including kindergartens and nurseries)

70
65 (during examinations)



Notes:

  1. The above standards apply to uses which rely on opened windows for ventilation and are assessed at 1m from the external façade.
  2. A Construction Noise Permit shall be required for carrying out relevant construction work during restricted hours under the Noise Control Ordinance. In case the applicant would like to evaluate whether carrying out relevant construction works during restricted hours under the Noise Control Ordinance is feasible or not in the context of programming construction works, reference should be made to relevant technical memoranda issued under the Noise Control Ordinance.

Table 2 : Suitable Window Types for Noise Insulation


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

Window
types

Exceedance
over standard

Noise source

I

II

III

Road Traffic

β < 10

10 < β< 15

β > 15

Aircraft

-

β < 10

β > 10

Helicopter

β < 5

5 <β< 10

β > 10

Window Types and Noise Insulation Performance

  1. openable well-gasketted window, 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, TL of 32 dB or above in 250 Hz octave-band and STC 34 or above.
  3. openable well-gasketted windows, TL of 33 dB or above in 250 Hz octave-band and STC 38 or above.



Back