23 november 2012dpcm 5/12/19971 the italian law on building acoustics dpcm 5/12/1997 angelo farina...

23 November 2012 DPCM 5/12/1997 1

The Italian law on building acousticsThe Italian law on building acousticsDPCM 5/12/1997DPCM 5/12/1997

Angelo Farina

Dip. di Ingegneria Industriale – Università di Parma

Parco Area delle Scienze 181/A, 43100 Parma – Italy

farina@aidasrl.it

23 November 2012 DPCM 5/12/1997 2

D.P.C.M. 5 December 1997:D.P.C.M. 5 December 1997:

Titled:

Specification of acoustical passive performances of buildings

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D.P.C.M. 5 December 1997:D.P.C.M. 5 December 1997:

23 November 2012 DPCM 5/12/1997 4

D.P.C.M. 5 December 1997:D.P.C.M. 5 December 1997:

23 November 2012 DPCM 5/12/1997 5

D.P.C.M. 5 December 1997:D.P.C.M. 5 December 1997:

Triv

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D.P.C.M. 5 December 1997:D.P.C.M. 5 December 1997:

Summary: 5 acoustical requisites for buildings:

1.Facade sound insulation

2.Apparent sound reduction index of internal partitions

3.Normalized tapping noise level

4.Maximum “slow” SPL of discontinuous equipment

5.Leq of equipment in continuous operation

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Facade Sound InsulationFacade Sound Insulation

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Facade Sound Insulation (2):Facade Sound Insulation (2):D.P.C.M. 5/12/1997 – Annex A

The Standardized Facade Sound Insulation (D2m,nT), is defined by:

D2m = L1,2m – L2 is the SPL difference

L1,2m = SPL measured 2m far from the facade, caused by traffic noise, or by a loudspeaker, with an incidence angle of 45°;

L2 = average SPL inside the receiving room;

T = reverberation time inside the receiving room, in s, (ISO 3382 standard);

T0 = reference reverberation time, equal to 0.5s;

02,2 log10

T

TDD mnTm

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Facade Sound Insulation (3):Facade Sound Insulation (3):

D.P.C.M. 5/12/1997 – Alnnex A

The average SPL in the receiving room, L2, is computed with this formula:

Li are measurmenets performed in a number n of points. n is the integer number

just above 1/10 of the room’s volume, in cubic meters. In any case, the minimum

value for n is 5.

n

i

Li

nL

1

102 10

1log10

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Facade Sound Insulation (4):Facade Sound Insulation (4):

D.P.C.M. 5/12/1997 – Annex A

a. The ISO 3382-1975 standard (reverberation time) was subsequently updated

in 1997 and in 2008;

b. The DPCM does not specify that the volume of the receiving room has to be

expressed in cubic meters;

c. The quantity denoted D2m,nT is defined in UNI EN ISO 140-5 as normalized

facade insulation (and not “standardized”);

d. The UNI 8270 standard, defining the single-number rating of facade

insulation, has been superseded by UNI EN ISO 717/1.

NOTES:

23 November 2012 DPCM 5/12/1997 11

Facade Sound Insulation (5):Facade Sound Insulation (5):

Norma EN ISO 717-1:1997

Single-number rating

For getting a single number giving the weighted normalized facade insulation, D2m,nT,w, the following procedure must be followed.

The ISO 717 reference spectrum must be moved down, with 1dB steps, over the measured spectrum of D2m,nT.

At each step, the sum of unfavorable deviations is computed (an unfavorable deviation occurs when the measured value, at a frequency band, is below the corresponding vale on the reference curve).

When the sum of unfavorable deviations becomes smaller than 32, the reference curve is properly positioned.

The weighted normalized facade insulation, D2m,nT,w is defined as the value of the reference curve at the frequency of 500 Hz.

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Facade Sound Insulation (6):Facade Sound Insulation (6):

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Sound insulation of internal partitionsSound insulation of internal partitions

Attention!

Only partitions between two different properties are subjected to the law!

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D.P.C.M. 5/12/1997 – Allegato A

a. The apparent sound reduction index R’ is defined by the EN ISO 140-4:2000

(and NOT by EN ISO 140-5:1996, as incorrectly written in the DPCM).

b. The UNI 8270 standard, defining the single-number rating of facade

insulation, has been superseded by UNI EN ISO 717/1.

NOTES:

Sound insulation of internal partitions (2):Sound insulation of internal partitions (2):

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EN ISO 140-4:2000 standard

Sound insulation of internal partitions (3):Sound insulation of internal partitions (3):

Sound Insulation, D: Diffrence, in dB, between the spatially and temporally averaged values of the SPL in the two rooms:

The apparent sound reduction index, R’ is given by:

where:

D is the Sound Insulation;

S is the area of the wall separating the two rooms;

A is the equivalent absorption area of the receiving room.

21 LLD

A

SDR log10'

L1 is the average SPL in the transmitting room;

L2 is the average SPL in the receiving room.

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EN ISO 140-4:2000 standard

The equivalent absorption area of the receiving room, A, is computed as:

where:

V is the volume of the receiving room, in cubic meters;

T is the reverberation time measured inside the receiving room.

T

VA 16.0

Tapping Noise (4):Tapping Noise (4):

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Sound insulation of internal partitions (5):Sound insulation of internal partitions (5):

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Tapping NoiseTapping Noise

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D.P.C.M. 5/12/1997 – Annex A

a. The normalized tapping noise level (L’n), is defined by the UNI EN ISO

140-7:2000 stndard, instead of EN ISO 140-6:1996, as written in the DPCM.

The latter is for laboratory measurments, whilst the DPCM is referring to “in

situ” measurments.

b. The UNI 8270 standard, defining the single-number rating of normalized

tapping noise level, has been superseded by UNI EN ISO 717/2.

NOTES:

Tapping Noise (2):Tapping Noise (2):

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UNI EN ISO 140-7:2000 standard

Average tapping noise level, Li: is the average SPL measured inside the receiving room when the standardized tapping machine is operating inside the adjacent room.

Normalized tapping noise level, L’n: it is the average tapping noise level corrected by a term taking into account the equivalent absorption area of the receiving room, with reference to a standard absoprtion area A0:

where: A0 = 10 m2.

0

log10'A

ALL in

Tapping Noise (3):Tapping Noise (3):

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UNI EN ISO 140-7:2000 standard

The equivalent absorption area of the receiving room, A, is computed as:

where:

V is the volume of the receiving room, in cubic meters;

T is the reverberation time measured inside the receiving room.

T

VA 16.0

Tapping Noise (4):Tapping Noise (4):

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Tapping Noise (5):Tapping Noise (5):

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HVAC and plumbing noiseHVAC and plumbing noise

• The measurement is to be performed inside a different room (of a different owner) than the one where the equipment is operating

• An explanation form the Ministry clarifies that the limit values are those reported in table B.

• The “general limits” of 35 e 25 dB(A) contained in the descriptive part of the DPCM are just a “lapsus calami” and are valueless.

• The noise produced by common (condominial) equipment are NOT subjected to the differential limits given by DPCM 14/11/1997 “Determinazione dei valori limite delle sorgenti sonore”

23 November 2012 DPCM 5/12/1997 24

Tricks (facade insulation):Tricks (facade insulation):Isolamento di facciata

Vetro “SANCOPHON 6/12/4+4 Acustico” (D2m,nT,W = 37dB)

10

15

20

25

30

35

40

45

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

Frequenza (Hz)

D2m

,nT

(d

B)

Isolamentodi facciata

Curva diriferimento

Isolamento di facciata Vetro “SANCOPHON 6/12/4+4 Acustico” + bordo di cartongesso

(D2m,nT,W = 36 dB)

10

15

20

25

30

35

40

45

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

Frequenza (Hz)

D2m

,nT

(d

B)

Isolamentodi facciata

Curva diriferimento

Interrupted gasket:

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Tricks (facade insulation):Tricks (facade insulation):

solamento di facciata Vetro “SANCOPHON 6/12/4+4 Acustico”

(D2m,nT,W = 42dB)

10

15

20

25

30

35

40

45

50

55

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

Frequenza (Hz)

D2

m,n

T (d

B)

Isolamento acustico normalizzato rispetto al tempo di riverberazione Curva di riferimento

Continuous gasket:

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Tricks (facade insulation):Tricks (facade insulation):

"Isolamento Facciata" Indice di valutazione dell'isolamento acustico standardizzato di facciata (D2m,nT,w = 37 dB)

37

15

20

25

30

35

40

45

50

55

50 63 80 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000

Frequenza (Hz)

D2m

,nT

(d

B)

Curva di riferimento norma ISO 717-1

Curva dell'isolamento acustico standardizzato di facciata normalizzato rispetto al tempo di riverbero

Bad sealing around the frame of the window: D2m,nT,w = 37 dB

23 November 2012 DPCM 5/12/1997 27

Tricks (facade insulation):Tricks (facade insulation):Good sealing around the frame of the window: D2m,nT,w = 41dB

"Isolamento Facciata" Indice di valutazione dell'isolamento acustico standardizzato di facciata (D2m,nT,w = 41 dB)

41

15

20

25

30

35

40

45

50

55

50 63 80 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000

Frequenza (Hz)

D2m

,nT

(d

B)

Curva di riferimento norma ISO 717-1

Curva dell'isolamento acustico standardizzato di facciata normalizzato rispetto al tempo di riverbero

23 November 2012 DPCM 5/12/1997 28

Psychoacoustic effectPsychoacoustic effect

Indice del potere fonoisolante apparente di partizioni tra ambienti (R'w = 53 dB)

15

20

25

30

35

40

45

50

55

60

65

70

50 63 80 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000

Frequenza (Hz)

R' (

dB

)

Curva di riferimento Curva del potere fonoisolante apparente

53

Complaints for low insulation (R’w = 45 dB)

After rebuilding the partition: R’w = 53 dB,

But the residents still complain….