A thermal conductivity map constitutes an important basis with regards to the design and performance of geothermal heat pump installations. Although the execution of a Thermal Response Test means an ideal solution as it provides the average value of the thermal conductivity over the length of the borehole drilled for the BHE, in small projects it is not possible to carry out these tests because they involve a huge increase of the total budget of the user. This study describes a systematic methodology to produce a thermal conductivity map of an area geographically placed in the center of Spain, the province of Avila. As a result, a map of thermal conductivity distribution of local rocks is proposed. (C) 2016 Elsevier Ltd. All rights reserved.