1. The Italian law on building acoustics DPCM 5/12/1997
09/13/2003
The Italian law on building acoustics DPCM 5/12/1997
Angelo Farina 1
Dip. di Ingegneria Industriale – Università di Parma
Parco Area delle Scienze 181/A, Parma – Italy
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DPCM 5/12/1997
AES 115th Convention - New York, NY

2. D.P.C.M. 5 December 1997: Titled:
Specification of acoustical passive performances of buildings
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3. D.P.C.M December 1997:
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4. D.P.C.M December 1997:
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5. D.P.C.M December 1997:
Triv
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6. D.P.C.M December 1997:
Summary: 5 acoustical requisites for buildings:
Facade sound insulation
Apparent sound reduction index of internal partitions
Normalized tapping noise level
Maximum “slow” SPL of discontinuous equipment
Leq of equipment in continuous operation
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7. Facade Sound Insulation
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DPCM 5/12/1997
AES 115th Convention - New York, NY

8. 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;
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9. 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.
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10. Facade Sound Insulation (4):
D.P.C.M. 5/12/1997 – Annex A
NOTES:
The ISO standard (reverberation time) was subsequently updated in 1997 and in 2008;
The DPCM does not specify that the volume of the receiving room has to be expressed in cubic meters;
The quantity denoted D2m,nT is defined in UNI EN ISO as normalized facade insulation (and not “standardized”);
The UNI 8270 standard, defining the single-number rating of facade insulation, has been superseded by UNI EN ISO 717/1.
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11. Facade Sound Insulation (5):
EN ISO 717-1:1997 standard
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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12. Facade Sound Insulation (6):
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13. Sound insulation of internal partitions
09/13/2003
Sound insulation of internal partitions
Attention!
Only partitions between two different properties are subjected to the law! 13
23 November 2012
DPCM 5/12/1997
AES 115th Convention - New York, NY

14. Sound insulation of internal partitions (2):
D.P.C.M. 5/12/1997 – Allegato A
NOTES:
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).
The UNI 8270 standard, defining the single-number rating of facade insulation, has been superseded by UNI EN ISO 717/1.
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15. Sound insulation of internal partitions (3):
EN ISO 140-4:2000 standard
Sound Insulation, D: Diffrence, in dB, between the spatially and temporally averaged values of the SPL in the two rooms:
L1 is the average SPL in the transmitting room;
L2 is the average SPL in the receiving room.
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.
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16. Tapping Noise (4): 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.
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17. Sound insulation of internal partitions (5):
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18. Tapping Noise 23 November 2012 DPCM 5/12/1997 09/13/2003 18
AES 115th Convention - New York, NY

19. Tapping Noise (2): D.P.C.M. 5/12/1997 – Annex A NOTES:
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.
The UNI 8270 standard, defining the single-number rating of normalized tapping noise level, has been superseded by UNI EN ISO 717/2.
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20. Tapping Noise (3): 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.
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DPCM 5/12/1997

21. Tapping Noise (4): 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.
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22. Tapping Noise (5):
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23. HVAC 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”
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24. Tricks (facade insulation):
Interrupted gasket:
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25. Tricks (facade insulation):
Continuous gasket:
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26. Tricks (facade insulation):
Bad sealing around the frame of the window: D2m,nT,w = 37 dB
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27. Tricks (facade insulation):
Good sealing around the frame of the window: D2m,nT,w = 41dB
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28. Psychoacoustic effect
Complaints for low insulation (R’w = 45 dB)
After rebuilding the partition: R’w = 53 dB,
But the residents still complain….
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