Acoustic regulations and classification schemes for dwellings typically include criteria for sound insulation and service equipment noise. Regulations specify minimum requirements, while classification schemes have quality classes reflecting different acoustical comfort/protection levels. Acoustic regulations and classification schemes were developed without coordination between countries, and comparative studies have shown that acoustic descriptors and limit values differ widely. In addition, classification schemes represent a diversity of class intervals, ranges and denotations. The situation looks like CHAOS and is an obstacle for exchange of construction experience, implying also trade barriers. In 2008, an initiative towards harmonization led to establishing the European COST Action TU0901 (2009-2013) with members from 32 countries. One of the results was a draft international acoustic classification scheme, which subsequently became WI in ISO/TC43/SC2. However, due to various, different long-lasting national traditions causing resistance to changes, there were several CHALLENGES on the road. Nevertheless, over time discussions were leading to improved mutual understanding and more COMPROMISES, but obstacles still exist and the final steps will hopefully lead to a reasonable CONSENSUS, since a joint international document increases awareness on acoustics among authorities, builders and building industry and provides a common ground for collecting experiences for future discussions, research and revisions.
