The central sound insulation standard for building in Germany, DIN 4109, was issued in a revised version in July 2016. The calculation procedures described in the standard can now be used to verify constructional sound insulation for masonry buildings with insulated external walls. For other building materials and construction methods, the minimum requirements can be verified, or if required the enhanced requirements. Measurements in completed buildings confirm the results and show that provided the construction materials are suitable and the specialist design is correct, good sound protection is regularly achieved.