Soundproofing of private houses and public facilities as part of environmental measures at Narita Airport

摘要

This paper gives an outline of soundproofing programs of private houses and public facilities as part of the main environmental policies of the Narita International Airport Corporation (NAA) to mitigate noise impact on people around Narita Airport. First, it explains a soundproofing program carried out under the so-called Aircraft Noise Prevention Law. NAA has subsidized inhabitants for soundproofing of their private houses within a noise zone. The method of soundproof construction work is determined according to noise exposure at the area concerned and the target sound insulation performance is evaluated, being based on the sound transmission loss at a 500Hz octave band. In case of Type-A and Type-B construction methods, soundproofing work is applied to all boundary sectors of the target sound insulation block, while in case of Type-C method soundproofing is applied only to exterior openings. NAA also pays subsidies to regional authorities for soundproofing schools, nurseries, hospitals and other facilities. Second, it explains an obligatory soundproofing program based on the Special Act for Aircraft Noise Prevention, which was enacted to prevent urbanization of the rural districts surrounding the airport. The law requires that schools buildings, hospitals and houses cannot be built without soundproofing in a different noise zone. Finally, it refers to a sound insulation program which regional governments and the Narita Airport Regional Symbiosis Promotion Foundation carry out. Subsidy for soundproofing is applied to private houses within the noise impact area outside the noise zone specified by the Aircraft Noise Prevention Law.