UPDATED on September 24, 2013

We’re all familiar with the food pyramid — the triangle with grains and cereals at the bottom and fats and sugars at the top. Inspired by the food pyramid, a Midwestern electric utility, Minnesota Power, has created a useful graphic called the energy conservation pyramid. (According to a Minnesota Power spokesperson, the originator of the conservation pyramid was Bob McLean, the chief operating officer at Hunt Utilities Group.)

The energy conservation pyramid includes ten levels. Like the food pyramid, it’s read from the bottom up. Homeowners who are uncertain of the best way to lower their energy bills should start at the lowest level of the pyramid and work their way up. In general, one shouldn’t proceed to a higher level until the actions below that level have been completed.

Actions near the bottom of the pyramid are much more cost-effective than actions near the top of the pyramid. At current energy prices, in fact, the actions listed on the top two layers are never cost-effective.

The rules displayed in the energy conservation pyramid are not set in stone; every house is different, and different climates dictate different strategies. But it’s hard to quibble with the pyramid’s basic hierarchy.

From the bottom up, here are the pyramid’s ten steps.

1. Home energy audit

Before beginning any energy retrofit work, a homeowner needs information — information best obtained through a home energy audit.

A good home energy audit always includes a blower-door test; most audits also include a thermographic inspection. To be sure your auditor is well trained, choose one certified by RESNET, BPI, or CBPCA.

A home energy audit can cost as much as $600. Thanks to subsidies from utilities and local governments, however, the cost of a home energy audit is often much…