N.Y.C. Admin. Code § BC 1207: Section BC 1207: Sound Transmission

1207.1 Scope.

This section shall apply to common interior walls, partitions and floor/ceiling assemblies between adjacent dwelling units, between dwelling units and adjacent mechanical equipment spaces, or between dwelling units and adjacent occupancies, and public areas such as halls, corridors, stairs or service areas.

1207.2 Air-borne sound.

Walls, partitions and floor/ceiling assemblies separating dwelling units from each other, from adjacent occupancies, from public or service areas, from stairs or from mechanical equipment spaces, including boiler rooms, or elevator or other shafts shall have a sound transmission class (STC) for air-borne noise of not less than 50 based upon laboratory measurements made in accordance with ASTM E 90, or not less than 45 if field tested in accordance with ASTM E 336. Dwelling unit entrance doors shall be installed of assemblies having an STC of not less than 30 based upon laboratory measurements made in accordance with ASTM E 90. Penetrations or openings in construction assemblies for piping; electrical devices; recessed cabinets; bathtubs; soffits; or heating, ventilating or exhaust ducts shall be sealed, lined, insulated or otherwise treated to maintain the required ratings.

1207.2.1 Masonry.

The sound transmission class of concrete masonry and clay masonry assemblies shall be calculated in accordance with TMS 302 or determined through testing in accordance with ASTM E 90.

Table 1207.2.1 Maximum Sound Pressure Levels for Machine Rooms Adjacent to Dwelling Units, Measured in the Dwelling Unit

Octave Bands, Hz Mid-Frequency

Max. Sound Pressure Level db

a

db re 0.0002 microbars 

63

61

125

53

250

46

500

40

1,000

36

2,000

34

4,000

33

8,000

32

a. The maximum sound pressure levels shall be reduced 5 db in any octave band where the equipment data indicate pure tone generation. The presence of pure tones may be determined by means of one-third octave band analysis. The criterion for a significant pure tone component shall be an audible pure-tone sound together with an increase of the sound pressure level in the corresponding one-third octave band above the mean of the two adjacent one-third of at least:

Center frequency of one-third octave band:

40/125

160/250

215/500

630/1,000

1,000/10,000

Increase in sound pressure level (db):

6

4

3

2

1 1/2

Elevator machine rooms and machinery spaces containing equipment totaling more than 75 rated h.p. shall not be located vertically or horizontally adjacent to dwelling units unless the total sound pressure level output of all the equipment in the machine room or space is certified not to exceed the maximum sound pressure levels of Table 1207.2.1 in any octave band.

1207.3 Structure-borne sound.

Floor/ceiling assemblies between dwelling units and sleeping units or between a dwelling unit or sleeping unit and a public or service area stair, exterior mechanical equipment, or other mechanical equipment space, including boiler rooms, shall be constructed of assemblies having an impact insulation class (IIC) rating of not less than 50 based upon laboratory measurements made in accordance with ASTM E 492, or not less than 45 if field tested in accordance with ASTM E 1007 in completed construction. See Chapter 30 of this code for additional sound control requirements for elevator machinery.

1207.3.1 Refuse chutes.

Metal refuse chutes, metal chute supports, and metal chute bracing shall be free of direct contact with the shaft enclosure and the openings provided in the floor construction. Metal chutes shall be resiliently supported at each structural support location. Isolators shall provide a minimum static deflection of 0.3 inches (7.62 mm). All chutes shall be plumb.

1207.4 Field testing.

Where conditions indicate that the installed construction or equipment does not meet the noise control prescribed in Section 1207, measurements shall be taken to determine conformance or non-conformance.