There are several terms being used to describe high-performance homes: zero energy, net-zero energy, near-zero energy and zero carbon. A true zero energy or net-zero energy home will produce enough energy during the course of a year to match the amount of energy it uses. Near-zero energy homes typically have greatly reduced energy bills but don't produce quite as much energy as they need overall. A zero carbon home generates extra energy to offset the carbon used in the actual construction of the home as well.

Energy efficiency has been the primary focus for cutting edge home building for a while now. Starting with the Environmental Protection Agency's Energy Star program several years ago, homes began to go beyond mere code requirements, offering buyers the promise of lower utility bills. Green-building programs take it several steps further, with environmentally friendly materials, greater water efficiency, healthier air quality and other improvements. But energy remains king.

Some progressive builders around the country are going beyond the requirements of even most green-building programs, finding creative ways to incorporate renewable energy systems as standard features, not expensive options or additions to traditional base models. Some states have incentives that builders can take advantage of, and economies of scale help bring costs down as well. This has resulted in high-performance homes that are, in some cases, priced at or even below those of their traditionally built competition.

The bottom line for a homeowner is monthly operating cost, which is primarily a combination of the mortgage payment and the utility bills. Even for homes costing more up front, the reduction in utility bills can often outweigh the higher monthly mortgage payment, resulting in net positive cash flow from day one.

There are many ways to build zero energy homes and strategies often vary with geographic location. What makes sense in Washington or Maine may be quite different from what works in Florida or California. Regardless of specific techniques, there are still some common principles that are typical for any ZEH.

First and foremost is efficiency. Once energy needs are reduced, renewable energy systems can be sized appropriately, keeping costs as low as possible.

The cheapest watts are negawatts, or those that can be avoided, and we have a lot of them! Experts have advised the Western Governor's Association that implementing "best practices" over the next 15 years could reduce the need to construct new generating facilities in the West by 48,000 megawatts, save 1.8 trillion gallons of water and create a net regional economic gain of $53 billion. Zero energy homes will play a key role in this scenario.

The concept of a zero energy home is usually reserved for new construction but there's no reason that motivated owners of older homes can't achieve this goal as well. Through a well-planned, logical process of upgrades and improvements, almost any home can be modified to reduce its energy consumption significantly.

There is tremendous satisfaction awaiting those who achieve energy independence. The joy of lower utility bills for the life of the home is obvious. High-performance homes typically have higher resale values and are more desirable in a tight market. The utility company wins as well since the cost of building expensive central power plants can be avoided. The environmental benefits are the icing on the cake of a zero energy home.

Not all builders are up to speed on this yet, but some major ones are stepping up to the plate. If you're looking for a new home, ask a lot of questions and let the builder know how you feel about the idea of high-performance, net-zero energy homes. Chances are they'll be listening. Even if they aren't building them now, they'll see the writing on the wall. Sooner or later, zero energy homes will be coming to a neighborhood near you!

Steve Rypka is a green living consultant and president of GreenDream Enterprises, specializing in renewable energy, green building, alternative transportation and lifestyle choices for both residential and commercial clients. The company is committed to helping people live lighter on the planet. Rypka can be reached via e-mail at steve@greendream.biz. More information relating to this column is posted at www.greendream.biz.