Construction industry design standards are increasingly calling for new construction to be inspected and tested for compliance with design specifications after the project is built; otherwise known as the commissioning process. As part of this trend, owners, sensitive to the acoustics of their facilities, are seeking confirmation via measurements that their buildings meet sound isolation and background noise requirements, particularly when pursuing certifications under the US Green Building Council LEED standard, the WELL Building Standard, or other green building or wellness standards. In general, the error of sound isolation measurements is not officially established. This poses challenges to designers tasked with specifying assemblies and components to meet field verification requirements. This paper will briefly review current research and standards on the error of measurements such as Noise Isolation Class (NIC) and the Weighted Level Difference (D) and discuss example design standards and guidelines which do or do not account for this error. It will also propose further research topics to better define the error in sound isolation measurements and best practices when establishing or designing to sound isolation criteria in new or renovated buildings.