This paper presents an overview of the results from a recently completed study on the assessment of the characteristics, current energy consumption and the potential for energy conservation in 29 Hellenic airports. The average annual total energy consumption at the airport terminals is 234 kWh/m(2). A more detailed investigation for three representative airports, at different climatic zones, was also performed. Data was collected through energy audits of the three terminal buildings, thermal infrared (IR) inspections of the building envelopes and HVAC installations, an assessment of indoor environmental quality (IEQ) through long term monitoring and spot measurements of indoor thermal and visual conditions, as well as personnel and passenger questionnaires. The collected information was used to perform a detailed analysis using thermal simulations for assessing specific measures to reduce energy use without compromising comfort, and to identify possible actions for improving IEQ. For the three airports, potential energy savings range at 15-35%, while improving and maintaining indoor environmental quality. (C) 2003 Elsevier B.V. All rights reserved.