This paper presents the application of degree-days utilized for the exergy analysis of buildings. The climate is observed as a basis for the exergy analysis of the energy usage of buildings. The definitions and functions of the outdoor temperature distribution density and its cumulative distribution frequency are introduced in the analysis. There are several relative exergy indicators for local climate conditions that are considered in the exergy analysis of the energy usage of buildings. The setting of these parameters allows the thermodynamic evaluation of engineering heating practices in separate locations. (C) 2010 Elsevier B.V. All rights reserved.