green building materials

When you're trying to create a sustainable new home or renovation the embodied energy of building materials is a key consideration. In this section you'll find:

• Embodied energy explained
• Life cycle analysis explained
• Low embodied energy materials

Embodied energy explained

When you want to assess the impact on the environment of the building materials you're thinking of choosing, embodied energy is a key measure. Using materials with high embodied energy is like having a big carbon emission balance before you've even started building.

The higher the embodied energy, the more energy has been consumed in the manufacture of the product, and the more carbon emissions have occurred.

Life cycle analysis

Embodied energy is the energy consumed by all the processes that are associated with the manufacture of the product. It's one of the things that can be measured by undertaking what's called a life cycle analysis.

A life cycle analysis tries to take a holistic look at the environmental impact of a material by classifying them in terms of:

• Resource depletion
• Inherent pollution
• Embodied energy

CSIRO research indicates that on average, the materials used to build a home have already used about 10 times the annual operating energy of the home. As a result, no matter how energy efficient the home is top operate, you're already way behind the eight ball.

Low embodied energy materials

Lightweight construction has a generally much lower embodied energy than construction systems that use masonry materials like brick.

For example:

• The embodied energy of a double brick wall is almost four times more than that of a timber-framed and fibre cement clad wall.
• The embodied energy of a brick veneer wall is almost 2 ½ times the embodied energy of a timber-framed and fibre cement clad wall.
• The embodied energy of a timber-framed and elevated sub-floor (typically used in lightweight construction) is less than half that of a concrete slab.

This video shows how this NSW-based builder went to a lot of effort to use materials with low embodied energy.

The graph below shows the embodied energy of a range of common construction systems.

You can read more about low embodied energy lightweight materials in this article: embodied energy