The future of building is not about any radical change in the way houses and other buildings look. It goes deeper, to the way they work, and here the change is nothing short of revolutionary.
Put simply, these are houses that will produce as much energy as they use. This balance is summed up in the name they are known by: zero energy or net-zero energy homes. It doesn’t stop there, though. The spirit, if not the letter, of zero energy homes requires that the energy produced must be from completely natural renewable energy sources—typically solar, but possibly wind too—converted into electricity on the property. What isn’t used at the time is fed into the local utility grid. Any energy consumed when the sun isn’t shining or the wind blowing is also electricity, supplied to the home by traditional, often fossil fuel-burning power plants. Eventually, however, those plants will be replaced by solar, wind, geothermal, hydroelectric, and ocean-wave power facilities—as they have been in a few communities to some degree today—when coal, oil, propane, and natural gas supplies start running out or become more expensive than the renewable sources (and nuclear facilities become untenable).
A zero energy home consumes very little energy. The amount should be at least two-thirds, and hopefully as much as 90%, less than what’s consumed by a standard house of the same size. Smaller houses trump larger, too—the better to reduce the amount of energy used.
Inside the house, it’s mostly a story about the many ways—small, unseen, out of the way, or uncommon—that make up the structure and components of the house that will separate the future from the present and the past.
However, everything it takes to build the house of tomorrow is for sale today, bought off the shelf or off the Internet. Some of the features and ways of doing things will be new to most homes, though much of what makes up a zero energy house will just be more efficient versions of what’s already in them.
In the package of features that make up a zero energy home there can be heat or energy recovery ventilator systems, tankless water heaters, heat pumps, fiberglass doors, low-flow showerheads, Energy Star top-freezer refrigerators, front-loading clothes washers, LED lighting, and cellulose and foam insulation, as well as triple-pane, gas-filled windows and solar-electric modules.
As important as its components is its affordability: a zero energy home must be priced within the means of the average home buyer. Ideally, zero energy homeowners would wind up paying nothing for the electricity they consumed over the course of the year. For the owners of a typical American house, eliminating the entire energy cost in an all-electric zero energy home could be a savings of about $2,200 annually (2009 figures). It can also mean more money in the pocket later, when the house is sold. In a study appearing in The Appraisal Journal, a home’s value was said to increase an average of $20 for each $1 decrease in the annual utility bill.
Besides dollar savings, a higher quality of life—by a number of different measures—is another advantage of living in a zero energy home. These homes are quieter, maintain temperature settings better, allow more natural light, have better air quality, and may stand up to storms better than traditional homes.
But as welcome as these advantages are, they don’t speak to the reason why zero energy homes are—many people would say must be—the housing of the future. In the United States, buildings, both residential and commercial, account for roughly 40% of energy use and carbon emissions—more than either of the other two main sectors of the economy, industry and transportation. Throw in construction and demolition, and it increases to 50%.