In 2005 a base model for geographic information in the Netherlands was published named NEN 3610. The model consist of a modeling framework (based on the ISO19100 series) and a collection of extensible base classes. In the following years many organizations have built their models in conformance to this base model (IMRO, TOP10NL, IMTOP, IMWA, IMKICH, IMKL). The implementation of the base model strongly enhances the operational aspect of a successful National Geographic Register and related services. Moreover the base model approach has prepared the Netherlands for implementation of a similar approach followed in the INSPIRE initiative. Based on the experiences and national and international developments we are renewing the base model, this will be finished in 2009. In our paper we share our experiences with the base model of the last few years and give an overview of our proposed changes. The changes come from the following three main sources: NEN 3610 users were asked for change proposals, all current NEN 3610 models were analyzed for harmonization opportunities and finally the INSPIRE specifications that will probably influence many datasets under NEN 3610 were checked. Al these proposals were discussed in a NEN 3610 Framework group resulting in a new version of base model. The most notable changes with respect to the old version are: \u95 The introduction of design patterns as a way to harmonize data models. \u95 How to handle the fact that all organizations have a different way of looking at the world and hence splitting the same world into different classes. \u95 Integration of semantic decisions and implementation decisions in one model. As there are many similarities between the Dutch base model developments and the INSPIRE process we believe that conclusions from this project can be of benefit for the INSPIRE project and vice-versa.GIS TechnologyOTB Research Institut