Embodied Energy
From Swikipedia
Introduction
Embodied energy is defined as the available energy that was used in the work of making a product. It can be taken as the total primary energy consumed (carbon released over its life cycle). This would normally include (at least) extraction, manufacturing and transportation. Ideally the boundaries would be set from the extraction of raw materials (including fuels) until the end of the products lifetime (including energy from manufacturing, transport, energy to manufacture capital equipment, heating and lighting of factory, maintenance, disposal etc.), known as ‘Cradle-to-Grave’. It has become common practice to specify the embodied energy as ‘Cradle-to-Gate’, which includes all energy (in primary form) until the product leaves the factory gate. The final boundary condition is ‘Cradle –to-Site’, which includes all of the energy consumed until the product has reached the point of use (i.e. the building site).
The embodied energy varies from material to material. Also, it can be observed that the embodied energy of traditionally used materials is much less as compared to conventional building materials being used now-a-days.
References:
http://www.greenspec.co.uk/html/materials/embodied_energy.html
