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BEAM P

LUS FOR

E

XISTING

B

UILDINGS

I

NDOOR

E

NVIRONMENTAL

Q

UALITY

(I

EQ

)

V

ERSION

1.2

I

EQ

19 R

OOM

A

COUSTICS

Copyright © 2012 BEAM Society Limited. All rights reserved.

Page 141

6

IEQ

6.7

A

COUSTICS AND

N

OISE

I

EQ

19 R

OOM

A

COUSTICS

E

XCLUSIONS

Buildings/premises where speech intelligibility is not important, and

rooms of a special acoustical nature.

O

BJECTIVE

Improve the acoustical properties of rooms in which speech intelligibility

is important.

C

REDITS ATTAINABLE

1

P

REREQUISITES

None.

C

REDIT REQUIREMENT

1 credit for demonstrating that internal noise levels are within the

prescribed criteria and the mid-frequency reverberation time in applicable

rooms meets the prescribed criteria for give types of premises.

Based on the nature of the building, relaxation should be allowed in

considering the acceptance of this credit. The applicant should provide

full submission of the design and calculation to justify the relaxation.

A

SSESSMENT

There is no single all-encompassing set of criteria that will define good

acoustical properties for all types of rooms and uses. The Client shall

define the criteria appropriate to the type and use of the premises/rooms

in the building. The criteria for intruding noise level will be expressed in

terms of NC level. However, for the purposes of assessment account

should be taken of the criteria given below. Where alternative criteria is

used the Client shall provide evidence as to the suitability of the

alternative, e.g. by making reference to authoritative guidance. Likewise,

where criteria appropriate to the type and use of premises/spaces is not

stated herein, the Client shall provide evidence as to the suitability of the

criteria adopted. Mid-frequencies refer to 500Hz, 1kHz and 2kHz. The

internal noise sources shall include air conditioning units, breakout noise

from air ducts, air grills, etc.

Compliance shall be demonstrated by detailed calculations, or

measurement, or both, depending on the Client’s preference. The

reverberation time shall be assessed using Sabine’s formula [ 1 ] or

similar alternative taking into account the room details and appropriate

assumptions about the materials in the space. Measurements during

commissioning shall use the method given in ISO 3382 [2] or equal

equivalent.

The Client shall submit details in the form of a report prepared by a

suitably qualified person providing a schedule of the premises and

spaces in the building, relevant design details as they impact on

acoustical properties, the rooms/premises subject to field tests or for

which detailed calculations have been made, the acoustical criteria used,

underlying assumptions, and the results of tests or calculations

demonstrating compliance with the criteria.

Where it can demonstrate that the acoustical quality in a sample of each

type of room in which speech intelligibility is important, as measured or

calculated, meets appropriate performance criteria the credit shall be

awarded.

1

I.Sharland. Woods practical guide to noise control. Colchester, England.

2

International Standard Organization. ISO 3382. Acoustics - Measurement of the reverberation time of rooms with reference

to other acoustical parameters.