It's nice to see the interest in improving our building heights data, however you can't use proprietary data when editing OSM https://wiki.openstreetmap.org/wiki/Copyright#Proprietary_data.

While sourcing a fact might be okay, in this case doing a bulk sourcing of their database is not okay. While their licensing terms at https://www.ctbuh.org/about/faq mention "public use" this is unclear.