What is Embodied Energy for Buildings?

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Embodied energy in common construction materialsMost people never stop to consider the real cost of the things they use, even if they're trying to be eco-friendly. They consider how much electricity an appliance uses, how much heat it generates and how much water it consumes... but few people go a step further and ask how much the raw materials cost to construct the appliance and how much energy was used in its manufacture.

Everything manufactured has embodied energy: it is a measure of how much energy is used in producing the item or material. There are entire web sites dedicated to tracking the energy footprint of almost anything you can imagine – and a lot of things you can't!

The practical effect of realizing that everything has a cost is that a homeowner can plan a new build or a retrofit with super-low-energy requirements. Some of the considerations are laid out below.

  • Low-energy appliances are an absolute must-have: front-loading washing machines, flat-screen televisions and power strips that automatically switch off when not in use all help conserve energy. If it doesn't have an Energy Star label, it shouldn't be in your home!
  • Low-energy lighting is also essential: exchanging standard light bulbs for compact fluorescent or LED alternatives not only reduces electricity use but also generates less heat, which in turn reduces cooling bills in summer.
  • Efficiency measures such as installing high-performance windows, increasing insulation to extreme levels and reducing air infiltration can also vastly improve the energy efficiency of a home.


Energy Star buildings

The Energy Star program was extended in 1996 and now covers buildings as well. It's a voluntary program, a partnership between builders and the EPA which targets energy performance. Rather than dictating what products can and cannot be used to win the label, the program looks at the overall performance of the final building and allows builders to choose whatever materials they consider best for the project.

The Energy Star label is only awarded when a third-party inspector has run a battery of tests on the building, plus checks on insulation, windows and other details.

There are several advantages to buying or building an Energy Star home. The most obvious of these is the fact that the house will be efficient to heat and cool, and comfortable to live in. However, the label can also provide access to a cheaper mortgage. Some providers offer an eighth of a point lower rates on Energy Star homes than on standard buildings – not much, it's true, but the difference can cover the extra cost of all the efficient materials and design built into the home, so you still come out ahead.

Of course, the biggest advantage of an Energy Star home is that, despite the higher initial outlay, the long-term costs are greatly reduced. The home is cheaper to heat and cool, giving exponential returns as fuel prices rise, and there is a measure of independence in times of crisis.