In this study, the connection of a local levelling network to the national height system in Sweden, RH 2000, with GNSS-techniques is investigated. The SWEN 08 is applied as geoid model. Essentially, the method is precise normal height determination with GNSS. The accuracy, repeatability and the affecting elements are tested. According to the statistics,the proposed method achieves 1-cm accuracy level. Suggestions on the general methodology and settings of several elements are proposed based on the statistics for the future application.