The ‘embodied energy’ of a building includes the energy used to extract, manufacture, and transport all the materials used. Once the energy needed in the day-to-day life of a building has been minimised, then the energy used in construction becomes a bigger proportion of the building’s overall energy use. So it makes sense when planning an energy efficient house to make careful choices about the materials used.
Of course, different building methods use differing amounts of materials, so it’s a matter of balancing the benefits of a particular method against its impact. A home built to passive solar design principles could have a solid concrete floor to store solar energy, and the energy gain from this may outweigh the impact of the materials.
The chart below shows the embodied energy of the main materials used for a conventional brick house, and those used in a well-insulated ‘eco-timber’ home. Harvesting and processing timber uses only a small amount of energy, so if you can buy local timber, the embodied energy will be quite low. You can reduce it still further by using locally reclaimed timber.