The performance and sustainability of ground source heat systems is dependent on the thermal behaviour of the neighbouring ground. This paper presents a field-scale monitoring scheme which has been designed and implemented to inspect the ground behaviour in response to a horizontal ground source heat system providing space heating to a domestic property. The system comprises of 112 thermistors buried in the ground along with sensors to record the influential climatic variables and system heating loads. Soil properties were also measured throughout the site as part of a wider site investigation. Dataset collected during the first 13 months of research is presented within the scope of this work. The resolution and duration of the collected dataset facilitated an extensive analysis including thorough investigations of ground thermal distributions resulting from heat extraction and recharge. Findings indicate that the horizontal ground source heat system implemented at the site has provided a sustainable source for space heating during 13 months period of inspection. The unsymmetrical distribution of ground temperatures observed highlighted the importance of climatic variables on ground-loop design and in doing so also highlighted potential avenues for future optimisation. Further to this, the compiled dataset can be considered as a significant contribution to the scientific aspects of ground thermal behaviour due to heat extraction/recharge and provides a comprehensive benchmark for the development and validation of predictive models. (C) 2016 Elsevier Ltd. All rights reserved.