Orthometric height determination with GNSS suffers from poor precision and accuracy, compared to the determination of planar coordinates. This project examines the capabilities of single-baseline RTK (SRTK) in interaction with the “dynamic reference point (DRP)”. The examinations are done by collecting observations at different baseline lengths, along with levelling and examinations of geoid models. A GNSS observation with corrections from an SRTK setup is examined to have a precision of 2.4 mm + 1.3 mm/km baseline length. Different geoid models are examined to have systematic biases, but within a limited area, the bias is constant. The orthometric height in the DRP solves the bias problem, by correcting the base height. Because of the corrected bias, an SRTK+DRP orthometric height observation can be accurate within 2.4 mm + 1.3 mm/km baseline length. The applicability and potential of the method are present. Resource demands of the method are significantly lower than competing and conventional methods, though the accuracy can not compete with geometric levelling.