A case study for implementation of the classification scheme introduced in the new sound insulation regulation in Turkey

The "Noise Protection and Sound Insulation in Buildings" regulation prepared by Istanbul Technical University for the Turkish Ministry of Environment and Urbanization, aims to organize the requirements and enforcements for noise control in buildings. This regulation introduces a classification scheme that ranges from A to F similar to what is proposed in the EU/COST TU 0901 Harmonization Project and the following draft standard ISO-CD19488. Acoustical performance class is assigned based on 6 acoustical performance parameters: airborne and impact sound insulation, façade sound insulation, indoor background noise levels, mechanical noise levels and reverberation time. Limit values for these performances are settled according to ISO-CD19488 but the scope is extended to all types of buildings. The minimum performance requirement is specified as class C for new buildings, and D for existing buildings, in the short term use of the regulation (which is subject to change over years). Due to on-going debates about the social and economical aspects and technical difficulties of including low frequency performances in calculations and measurements, the frequency range is currently accepted as 100 - 3150 Hz, except in two cases: where the low frequency component of noise is dominant or when the acoustical consultant considers to extend the adaptation term including 50 Hz necessary. In this study, 3 residential buildings were selected for the field measurements. Airborne sound insulation of partitions and façades are considered. The evaluation has started from 100 Hz and 50 Hz respectively. Based on the results, the applicability of the limit values and the classification system was shown. Measures to improve the sound insulation were discussed if the field values deviate from the regulation requirements in a considerable amount.