The single most important factor in reducing the impact of embodied energy is to design long life, durable and adaptable buildings.
Embodied energy can be the equivalent of many years of operational energy.
Research by CSIRO has found that the average household contains about 1000GJ of energy embodied in the materials used in construction. this is equivalent to about 15 years of normal operational energy use.
Assessing Embodied Energy:
Gross Energy Requirements (GER): (almost impractical to fully measure to a definite amount)
The energy used to transport the materials and workers to the building site.
Just the materials for the construction of the building shell or all materials used to complete the building such as fittings and flooring.
The upstream energy input in making the materials ( lighting within factory & energy in machinery used in factory).
The embodied energy of the urban infrastructure (roads, drains, water and energy supply).
Process Energy Requirements (PER): (the energy directly related to manufacturing the material)
Efficiency of the individual manufacturing process.
The fuels used in manufacture of the materials.
The distance the materials are transported.
The amount of recycled product used, etc.
Generally the more highly processed a material is the higher its embodied energy.
Guidelines for reducing embodied energy:
Design for long life and adaptability, using durable low maintenance materials.
Ensure materials can be easily separated.
Avoid building a bigger house than you need.
Modify or refurbish instead of demolishing or adding.
Ensure materials from demolition of existing buildings, and construction wastes are reused or recycled.
Use locally sourced materials (including materials salvaged on site) to reduce transport.
Select low embodied energy materials (which may include materials with a high recycled content) preferably based on supplier specific data.
Avoid wasteful material use.
Specify standard sizes, don’t use energy intensive materials as fillers.
Ensure off cuts are recycled and avoid redundant structures.
Cradle to Cradle: select materials that can be re-used or recycled easily at the end of their lives using existing recycling systems.
Give preference to materials manufactured using renewable energy sources.
Life Cycle Assessment (LCA) examines the total environmental impact of a material or product through every step of its life – from obtaining raw materials all the way through manufacture, transport to a store, using it in the home and disposal or recycling.