Embodied energy is one of the terms used to measure the impact of a product on our environment. An understanding of these terms is important for informed debate on environmental sustainability.
It measures the amount of energy involved in the extraction of raw materials, their transportation to the point of manufacture, the production process, delivery to the building site and installation of the product.
The table below shows the difference in embodied energy between Australia's three most trusted roofing materials: concrete and terracotta roof tiles and sheet metal roofing. The comparison has been carried out by constructing three roofs using commonly used construction materials (timber framing and plasterboard) while changing the one independent variable: the roof cladding. The results of the testing clearly identify concrete roof tiles as the lowest embodied energy product, followed by terracotta roof tiles, and finally sheet metal roofing having the highest embodied energy of the three materials tested.
| ASSEMBLY |
PER EMBODIED ENERGY MJ/m² |
| Timber frame, concrete tile, plasterboard ceiling |
251 |
| Timber frame, terracotta tile, plasterboard ceiling |
271 |
| Timber frame, steel sheet, plasterboard ceiling |
330 |
Source: Lawson Buildings, Materials, Energy and the Environment (1996)