This paper describes the motivation and problem statements as well as the ongoing investigations regarding the follow-up activities of the 3D Pilot NL. This pilot is a large collaboration in the Netherlands aiming at pushing 3D developments in the Netherlands. The first phase resulted in a national 3D standard, modeled as CityGML Application Domain Extension. Some insights obtained during this phase are sufficiently mature to be anchored in practice such as maintaining and further developing the 3D standard by Geon ovum and the provision of a countrywide 3D midscale base dataset which is currently under study at the Kadaster. Other results need further attention in a collaborative setting, specifically how the new 3D standard works in practice. This is currently being further explored in a second phase of the 3D Pilot in which over 100 organizations are participating. The goal of the follow-up pilot is more focused than the first pilot and aims at writing best practice documents by joint effort of the 3D Pilot community. The best practice documents are based on tools and techniques that are being developed for supporting the implementation of the 3D standard. Specific attention is being paid how to align City GML to the standard in the BIM (Building information Model) domain (IFC). Initial findings and work in progress are presented.