§ 119.20. Noise attenuation.
It is in the best interests of the city and of current and future residents that the integrity of all residential structures which have received a five (5) dB or other sound insulation package from the Metropolitan Airports Commission be maintained subject to the following:
(1)
Noise attenuation required—Expansion. Whenever construction of a habitable addition to a dwelling unit is undertaken which expands the habitable area of a dwelling unit which had previously received a five (5) dB sound insulation package from the Metropolitan Airports Commission pursuant to the consent decree or pursuant to previous noise mitigation programs of the Metropolitan Airports Commission, the construction must include installation of central air conditioning or mechanical ventilation for the expanded area. Such construction shall utilize materials with a sound transmission class (STC) rating of at least forty (40) in order to achieve similar noise attenuation in the expansion of the structure as existed in the principal structure prior to expansion.
(2)
Noise attenuation required—Infill or tear down/rebuild residential construction. Infill construction or rebuilding of residential structures after tearing down the original structure which takes place within blocks or between structures that had previously received a five (5) dB sound insulation package pursuant to the consent decree or pursuant to previous noise mitigation programs of the Metropolitan Airports Commission shall utilize building materials with a sound transmission class (STC) rating of at least forty (40) and shall include installation of central air conditioning or mechanical ventilation throughout the habitable areas of the structure.
(3)
Requirement within the 60—62 contours. Construction of new single family homes located in blocks or between structures that have received noise attenuation pursuant to the consent decree that are in the 60 to 62 DNL contours as defined in the consent decree shall include installation of central air conditioning or mechanical ventilation throughout the habitable portion of the structure.
(4)
Requirement for multiple-family homes within the 60—64 contour. Construction of new multiple-family homes in blocks that have received noise attenuation pursuant to the consent decree or which are between structures which have received noise attenuation pursuant to the consent decree or pursuant to previous noise mitigation programs of the Metropolitan Airports Commission shall install central air conditioning or mechanical ventilation throughout the habitable portions of the structure. (Ord. No. 2016-071 , § 1, 10-7-16)