The quality of energy and matter is expressed by the concept of "exergy." It represents the resource-capacity of
energy and matter, or their "ability to disperse themselves into their environment." Exergy can explicitly show us the degree of "consumption" quantitatively, which is brought by "dispersion" of energy and matter.
To increase the understanding of exergy flows in buildings and to be able to find possibilities for further improvements in energy utilisation in buildings a pre-design tool low EX have been produced during the work for the IEA ECBCS Annex 37.