Advantages of application the sound classification schemes were foreseen in the two applications. In the legal regulation, the scheme expresses in the users friendly and easy understandable form protection against noise requirements for the buildings. The scheme is also a tool for designer to advice criteria of the suitable acoustic comfort in premises and also to label buildings according acoustic quality. Classification scheme implemented in Lithuania comprise five acoustic comfort classes—A, B, C, D, and E. Acoustical requirements expressed by the C sound class limit values correspond to the at least acceptable acoustic comfort level. The lowest (worst) sound class is E and comprise limit values corresponding to the acoustical comfort level in old buildings erected under sound insulation requirements existed before. By this reason, the step in limit values between different classes cannot be permanent and depends from the changes in acoustical demands during the time. For enforcement, legal requirements expressed through mandatory sound class C for new dwellings and E for renovated buildings from 2007 pre-completing testing become mandatory. In this approach, more important becomes a guideline for verification of compliance with an acoustic class.