The 3D Basisregistratie Adressen en Gebouwen (BAG) is brought to you by the 3D geoinformation research group of the Delft University of Technology.
For any comments or remarks please send an e-mail to the developer, Balázs Dukai.
If you have a question or a problem to report, the best way to do so is in a GitHub issue here. In this way others can benefit from the information as well. Alternatively, you can send an e-mail to Balázs.