What is embodied energy? One definition is:

"The quantity of energy required by all of the activities associated with a production process, including the relative proportions consumed in all activities upstream to the acquisition of natural resources and the share of energy used in making equipment and in other supporting functions i.e. direct energy plus indirect energy." ( Treloar, 1994).

Basically, this means all the energy required to make a material, such as a clay brick. This includes the energy to extract the clay, transport it to the brick-works, mould the brick, fire it in the kiln, transport it to the building site and put the brick into place. It also includes all the indirect energy required, i.e., all the energy required to manufacture the equipment and materials needed to manufacture a brick, e.g. trucks, kilns, mining equipment, etc. All have a proportion of their energy invested in that brick.

So the components of embodied energy are the manufacturing, the transportation and the disposal energy. It has nothing to do with the internal energy of the materials. In our project we dealt with the manufacturing energy and this is the energy that our tool calculates.

The database was obtained by Ecobalance, a European organisation leader in the research of embodied energy. This database has some materials' manufacturing energy, since everything is at a research level. But every day more and more materials are added to this database.