What Does It Take to Achieve a Net-Zero-Energy Home?

Interest in greener buildings has skyrocketed in the last decade. From commercial properties taking steps to add green spaces on their rooftops to home builders and do-it-yourselfers making residential buildings more sustainable, the push toward greater energy efficiency in construction continues to gain momentum.....albeit at a pace far below the optimal.

Particularly with regard to home building and renovation, I frequently talk with people who want to turn their houses into net-zero-energy (NZE) or near-NZE living spaces, meaning that over the course of a full year, the residents consume no more energy than the home itself produces. Sounds tough, right? Maybe even downright impossible, especially for residents living in colder climates that demand home heating for six or more months each year?

Take it from me, I'm living proof that an NZE home is possible, even for someone who lives in the unpredictable climate of upstate New York, where temperatures can drop to 10-below zero in January and soar to over 100 in August. And as someone who moved here from the southwest, I wondered what kinds of challenges these seasonal changes would present someone aiming to achieve high energy efficiency in their home.

Because I've had a lifelong interest in sustainability, I wanted to build a house that reflected my beliefs. Fortunately for me, I found an innovative, skilled builder named Anthony Aebi who had a similar dream: to create a repeatable, cost-effective approach to achieving zero energy in a development he's creating called Green Acres in New Paltz, NY. I eagerly signed up to become the first resident. Green Acres now has five occupied homes and we can find no other examples in the world of a NZE development that has proven its claim.

So how do you get started in building an NZE home, with or without a committed builder? First, there are several misconceptions about projects like this. In particular, many believe it's an enormously expensive endeavor. That's simply not the case.

In our experience, we've found that it cost only 10 percent more to include the many energy efficiency features, while the payback period will be seven to 12 years, depending upon the price of heating oil. Added to this, based on recent sales of homes in the development, I strongly suspect that if I were to sell, I would recover most, if not all, of these additional costs -- even in this housing slump!

To help defray the costs, there are a number of federal and state incentives that can help as well. Take a look at the U.S. Department of Energy website to learn more about currently available tax credits and rebates.

Another common misconception is that adequate commercial technologies simply do not exist. As Anthony can testify, this also is a myth. Many large home appliance companies, such as WaterFurnace, are producing wonderful systems that are reasonably priced and perform very well.

My home combines a geothermal heating and cooling system (HVAC) along with solar panels, superior insulation and sealing. I also recover energy that would normally be lost in air exchange through a heat recovery ventilation system. My house is located about 90 miles north of New York City. Because of its latitude and weather conditions, this region isn't the easiest place to generate solar energy. Frankly, NZE is much easier to achieve in places like California, Arizona or throughout the south; so if we can do it here, it can be done virtually anywhere!

Now this is where taking a greener approach gets interesting. I pay $16 a month to the local utility here in New York in order to stay connected to their electrical grid. And last year, the utility actually paid me for the energy I sold back to them! Check out some of the features from my NZE home, then read on for some tips to put to use in yours:

Here are some more details on the specific features I've built into my NZE home. Perhaps you're interested in incorporating some or all of these into your home building or renovation project.
  • Solar panels. I upgraded to a 10 kilowatt system to ensure capacity to accommodate a plug-in hybrid or electric vehicle some day. Although installation of the solar panel system cost more than 85,000, state and federal rebates and tax incentives reduced the cost to less than 27,000.

  • Geothermal heating and cooling by means of a ground source heat pump, which is a highly efficient, electrically powered system that uses the earth's constant ground temperature to provide heating, cooling and hot water for homes and buildings. A federal tax incentive will reimburse 30 percent of the cost of the total system.
  • Superior insulation and sealing, including high-performance windows, insulated concrete forms and spray-foam insulation in the rafters (R-45). Most homes average 35 percent of air exchange per hour; my house limits the leakage of air to less than 7 percent. The basement is highly insulated, including double R-20 foam under the slab. Studies show that 40 percent of heat is lost through poorly insulated basements.
  • Heat-recovery ventilation, which uses electronic systems to exchange energy from indoor, conditioned air to incoming outdoor air, which recovers up to 88 percent of available (and normally lost) energy.
  • The only way we as a country are going to get away from our fossil fuel dependence is to tackle the biggest areas of energy waste. Buildings (commercial and residential) are well established as the single largest consumers of energy worldwide. Moving toward the zero-energy model is a great step in the right direction. I live in a true dream house, and it didn't require a huge trade-off to maintain environmental stability. I hope this inspires others to follow my lead.

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