Two common housing prototypes of existing buildings in Spanish rural areas were surveyed by infrared inspection. The aim of the study is to assess the usefulness of infrared thermography as a technique for the detection of the thermal performance of rural buildings. For the traditional house the best results were obtained in the thermographic survey carried out in the evening. Contrarily, for the modem house the thermographic survey at daybreak provided more information. Infrared thermography allowed the comparison of the thermal performance of two buildings. (C) 2004 Elsevier B.V. All rights reserved.