The “LEK”-concept and its applicability for the energy analysis of commercial buildings

Some recent efforts—particularly in the European context — have provided simple-to-use methods to describe and prescribe the overall heat transfer coefficient of building envelopes of small-scale heating-dominated buildings. One approach suggests the use of the so-called LEK-diagram (Line of European K-values) to establish a relationship between building geometry and the mean heat transfer coefficient of the building envelope. This paper examines the potential of utilization and the problems in development of similar — albeit extended — approaches in the more complex context of cooling-dominated buildings.