Sound insulation of dwellings - Legal requirements in Europe and subjective evaluation of acoustical comfort

Acoustical comfort is a concept that can be characterised by absence of unwanted sound and by opportunities for acoustic activities without annoying other people. In order to achieve acoustical comfort in dwellings certain requirements have to be fulfilled concerning the airborne sound insulation, the impact sound insulation and the noise level from traffic and building services.

For road traffic noise it is well established that an outdoor noise level LAeq, 24 h below 55 dB in a housing area means that approximately 15-20% of the occupants are annoyed by the noise. However, for sound insulation against noise from neighbours the relationship is not so well understood. A comparison of sound insulation requirements in different countries shows that the sound insulation requirements differ considerably in terms of the concepts used, the frequency range considered and the level of requirement. The most recent version of the standard ISO 717 has contributed to the diversity by allowing different concepts and by introducing spectrum adaptation terms with different - extended - frequency ranges for the evaluation.

The paper will present (a) an overview of the main characteristics of the legal sound insulation requirements in several European countries and (b) a review of investigations related to the subjective and/or objective evaluation. Based on the analysis of several investigations in the field and by laboratory simulations it is suggested how to estimate the degree of satisfaction with a specific requirement for sound insulation. The findings can also be used as a guide to specify acoustic requirements for dwellings in the future.