The Physikalisch-Technische Bundesanstalt (PTB) is responsible for the technical assessment of building acoustics test facilities for approval by the Deutsches Institut für Bautechnik (DIBt), the highest building authority in Germany. The test facility is tested by means of comparison measurements on reference elements from previous round robin tests and an on-site assessment. In addition to a special production of lime bricks for a heavy wall, the reference elements MIG I and MIG II for window test facilities are available for this purpose. Ceiling test facilities can currently only be tested by measuring the improvement of impact sound insulation on reference objects. Laboratories can also carry out measurements on these reference elements as part of their quality management without the involvement of the DIBt. Depending on the customer choice, PTB carries out verifying measurements on these objects on site. Due to these continuous measurements on the existing reference elements, the amount of data for window as well as wall and ceiling test facilities is constantly increasing. The statistical analysis of this data and the reference objects available will be presented.