A. Noise Insulation Required. All new residential dwelling units and the portion of new non-residential structures where the public is received or where offices are proposed must be constructed with sound insulation or other means to achieve a day/night interior noise level (Ldn) of no greater than 45 dB. A remodeling project where the total cost of improvements is 75 percent or more of the valuation of the existing building must also meet this standard.

B. Certified by an Acoustical Expert. An engineer registered in the State of Washington who is knowledgeable in acoustical engineering, an architect registered in the State of Washington who is knowledgeable in acoustic design, or an industrial hygienist must certify that the building plans comply with the performance standard for sound insulation prior to the issuance of a Building Permit.

C. Noise Contour Maps. A set of noise contour maps, known as the Pierce County 65 Ldn Noise Contour Maps, is available for review at the Department.

D. Noise Disclosure Statement. Prior to the issuance of a Building Permit for new construction or remodeling where the total cost of improvements is 75 percent or more of the valuation of the existing building, the property owner must sign a noise disclosure statement and record the statement with the title of the property. The noise disclosure statement acknowledges that the property is located within the 65 Ldn contour, as indicated on the Pierce County Noise Contour Maps, and that noise attenuation is required of any new construction or remodeled structure where it meets the threshold.