This data set consists of thermal property testing results including thermal conductivity, thermal diffusivity, porosity, permeability and density. The data is presented in an excel spreadsheet with two tabs, one containing the data itself and one containing a description of each column. The testing was carried out on behalf of the BGS Geothermal and energy storage programs between 2020 and 2025. The samples were predominantly plugs (24x38mm) or wedges (usually quarter core of various lengths) taken from borehole core. The following boreholes were sampled as part of the project. • UKGEOS CHESHIRE A-101 • Frodsham Marsh • Stanlow • Killingholme DG1 • Speke Reservoir • Carnaby • UKGEOS GGC01 • KEYWORTH D (GSHP 3) • SUTTON BONINGTON SB4 These sites were chosen to support characterisation activities around BGS projects such as the UK GeoEnergy Observatories project and the drilling of a ground source heat well on site at BGS Keyworth.