28-8482. Incorporation of sound attenuation standards in building codes

A. A political subdivision that includes territory in the vicinity of a military airport or ancillary military facility shall incorporate the sound attenuation standards and specifications prescribed in this section into any building code in existence on or adopted after December 31, 2001 or adopted on or after the date the land becomes territory in the vicinity of a military airport or ancillary military facility. These standards and specifications apply to new development and alterations for first occupancy that are the subject of building permits issued after December 31, 2001 or after December 31 of the year in which the land becomes territory in the vicinity of a military airport or ancillary military facility and that are located on property within the territory in the vicinity of a military airport or ancillary military facility and do not apply to new development and alterations that are located on property within corporate limits of a municipality but outside territory in the vicinity of a military airport or ancillary military facility.

B. Not later than December 31, 2001 or not later than December 31 of the year in which the land becomes territory in the vicinity of a military airport or ancillary military facility, a political subdivision that has territory in the vicinity of a military airport or ancillary military facility shall adopt an ordinance that requires a noise level reduction to be incorporated in the design and construction of any residential building or portions of buildings where the public is received, office areas and where normal noise level is low for first occupancy, including libraries, schools and churches, pursuant to building permits issued after December 31, 2001 in order to achieve a maximum interior noise level of forty-five decibels in areas within the noise contours described in section 28-8461, paragraph 9, subdivision (a), (b), (c) or (d), as applicable.  In order to comply with this section, an ordinance shall require that all residential buildings in territory in the vicinity of a military airport or ancillary military facility but outside the noise contours as described in this section shall be constructed with a minimum of R18 exterior wall assembly, a minimum of R30 roof and ceiling assembly, dual-glazed windows and solid wood, foam-filled fiberglass or metal doors to the exterior or, if the specified building standards are not met, the political subdivision may approve, as an alternative, a certification by an architect or engineer registered pursuant to title 32, chapter 1 to achieve a maximum interior noise level of forty-five decibels at the time of final construction.  A sound attenuation ordinance adopted by a political subdivision pursuant to this subsection shall not require a maximum interior noise level that is less than the maximum interior noise level required by this subsection.

C. The sound attenuation requirements of this section do not apply to ancillary buildings used in agricultural land use.

D. If the gross floor area of a structure or project is expanded by less than fifty per cent, the requirements of this section apply only to the area of expansion. If the gross floor area of a structure or project is expanded by fifty per cent or more, the requirements of this section apply to the entire structure, except for single family, mobile home, manufactured housing unit or duplex dwellings or any multifamily property used for residential purposes.

E. For the purposes of this section, political subdivision does not include a school district.