Alameda Municipal Code § 13-31 Noise Insulation Standards

The purpose of this section is to establish uniform minimum noise insulation performance standards to protect persons within new hotels, motels, apartment houses, and dwellings from the effects of excessive noise, including but not limited to hearing loss or impairment and persistent interference with speech and sleep.

(Ord. No. 2722 N.S. § 2)

The provisions of this section shall apply to all new hotels, motels and residential structures located within a high exposure area.

(Ord. No. 2722 N.S. § 2)

As used in this section:

High exposure area shall mean an area where the total community noise equivalent level (the CNEL of all sources), as determined by the general plan, attains or exceeds sixty-five (65) dB.

(Ord. No. 2722 N.S. § 2)

a. Location and Orientation. Consistent with land use standards, residential structures located in noise critical areas, such as proximity to select system of County roads and City streets (as specified in Section 186.4 of the State of California Streets and Highways Code), railroads, rapid transit lines, airports, or industrial areas shall be designed to prevent the intrusion of exterior noises beyond prescribed levels with all exterior doors and windows in the closed position. Proper design shall include, but shall not be limited to, orientation of the residential structure, setbacks, shielding, and sound insulation of the building itself.

b. Interior Noise Levels. Interior community noise equivalent levels (CNEL) with windows closed, attributable to exterior sources shall not exceed an annual CNEL of forty-five (45) dB in any habitable room.

c. Airport Noise Source. Residential structures to be located within an annual CNEL contour (as defined in Title 4, Subchapter 6, California Administrative Code) of sixty (60) dB require an acoustical analysis showing that the structure has been designed to limit intruding noise to the prescribed allowable levels. CNEL's shall be as determined by the general plan.

d. Vehicular and Industrial Noise Sources.

1. Residential buildings or structures to be located within exterior community noise equivalent level contours of sixty (60) dB of an existing or adopted freeway, expressway, major street, thoroughfare, bridge, railroad, rapid transit line or industrial noise source shall require an acoustical analysis showing that the proposed building has been designed to limit intruding noise to the prescribed allowable levels. CNEL's shall be as determined by the general plan.

2. Exception: Railroads, where there are no nighttime (10:00 p.m. to 7:00 a.m.) railway operations and where daytime (7:00 a.m. to 10:00 p.m.) railway operations do not exceed four (4) per day.

e. Parks, Playgrounds and Schools. Residential buildings or structures to be located within exterior community noise equivalent level contours of sixty (60) dB of an existing park, playground or school shall require an acoustical analysis showing that the proposed building has been designed to limit intruding noise to the prescribed allowable levels. CNEL's shall be as determined by the general plan.

f. High Exposure Area. Buildings located within a high exposure area shall require an acoustical analysis showing that the structure has been designed to limit noise to the prescribed allowable levels. CNEL's shall be as determined by the general plan.

(Ord. No. 1750 N.S.; Ord. No. 2722 N.S. § 2)

Evidence of compliance shall consist of submittal of an acoustical analysis report, prepared under the supervision of a person experienced in the field of acoustical engineering, with the application for building permit. The report shall show topographical relationship of noise sources and dwelling site, identification of noise sources and their characteristics, predicted noise spectra at the exterior of the proposed dwelling structure considering present and future land usage, basis for the prediction (measured or obtained from published data), noise attenuation measures to be applied, and an analysis of the noise insulation effectiveness of the proposed construction showing that the prescribed interior noise level requirements are met. If interior allowable noise levels are met by requiring that windows be unopenable or closed, the design for the structure must also specify the means that will be employed to provide ventilation, and cooling if necessary, to provide a habitable interior environment.

(Ord. No. 1750 N.S.; Ord. No. 2722 N.S. § 2)

a. Only when inspection indicates that the construction is not in accordance with the approved design, field testing may be required. Interior noise measurements shall be taken under conditions of typical maximum exterior noise levels within legal limits. A test report showing compliance or noncompliance with prescribed interior allowable levels shall be submitted to the Building Official.

b. Where a complaint as to noncompliance with this section requires a field test to resolve the complaint, the complainant shall post a bond or adequate funds in escrow for the cost of the testing. Such costs shall be chargeable to the complainant when such field tests show that compliance with these regulations is in fact present. If such tests show noncompliance, then such testing costs shall be borne by the owner or builder.

(Ord. No. 1750 N.S.; Ord. No. 2722 N.S. § 2)