Net-zero construction gains ground in U.S.

Apollo 11 touched down on the Sea of Tranquility with the world watching.

The date was July 20, 1969.

"Houston, Tranquility Base here. The Eagle has landed," the spacecraft announced. Some hours later Apollo 11 astronaut Neil Armstrong took man's first steps on the Moon followed closely by fellow spaceman Buzz Aldrin.

Their footprints at Tranquility Base likely remain, a small sign of a massive accomplishment.

NASA's back in the historic footprint game again but in an entirely different way. The space agency, now somewhat redirected and fiscally leaner with the closure of the Space Shuttle program, has been constructing a facility that takes inspiration for its name from Tranquility Base and seeks to be a landmark in another sense, leaving as little footprint as possible.

Here on Earth

Sustainability Base, at Ames Research Center in Moffett Field, Calif., has been dubbed NASA's latest mission on Earth. The facility has received LEED platinum certification, the highest level of Leadership in Energy and Environmental Design rating by the U.S. Green Building Council. Its design incorporates natural lighting, shading and fresh air. The interior boasts non-toxic materials and is, according to NASA, "a living prototype for buildings of the future."

The net-zero movement -- designing and building structures to make as little impact on the environment as possible -- is gaining steam, albeit slowly.

Commercial and residential buildings consume about 40 percent of all energy in the United States and about 70 percent of all electricity, according to the U.S. Energy Information Administration. And electricity consumption in the commercial building sector is expected to increase another 50 percent by 2025.

The net-zero or zero-energy building concept means commercial or residential buildings meet all their energy requirements from low-cost, locally available, nonpolluting, renewable sources, according to "Zero Energy Buildings: A Critical Look at the Definition," a 2006 study by the National Renewable Energy Laboratory. "At the strictest level, a ZEB generates enough renewable energy on site to equal or exceed its annual energy use," the study says.

Lunar design influence

Sustainability Base, which is shaped like two side-by-side crescents, gets its power from solar panels, wind energy and fuel cells. It's also chock full of other technologies that make it "capable of anticipating and reacting to changes in sunlight, temperature, wind and occupancy," officials say.

“What makes our building different than the other NASA LEED buildings is that preliminary data are already showing a net-energy positive profile. The building site contributes more energy to the grid than it receives from the grid," says Steven Zornetzer, associate center director for research at Ames, in a description of the base on Ames' website.

Because it also incorporates repurposed NASA aerospace technologies to optimize building performance, Sustainability Base's features cooler statistics than other net-zero buildings. For instance, it uses computational fluid dynamics to simulate environmental flows in and outside the building. This can mean air flows such as wind outside and air flow inside. The building's electronic systems calculate this information and incorporate the data into the heating and cooling systems, saving money in conventional heating and cooling.

Movement expands

Many efforts are under way to reduce production of greenhouse gases from the building sector. Retrofits of existing buildings, such as the iconic Empire State Building, have gained recognition, mostly because the energy-saving upgrades pay for themselves relatively quickly.

Measures are under way in a number of areas. They include sustainability policies from some of the largest publicly traded U.S. companies, efforts by states to increase efficiency through building codes (California's new rules took effect in 2011), programs by the U.S. Department of Energy to fund energy efficiency retrofits in municipal government buildings across the country and the whole house and passive house movements to increase efficiency in residential and commercial buildings.

The U.S. Department of Energy is seeking to develop the technology and a knowledge base for cost-effective zero-energy commercial buildings by 2025. The National Renewable Energy Laboratory already has created a classification system for net-zero energy buildings to aid in the standardization process. NREL's Research Support Facility on its Golden, Colo. campus also was certified LEED platinum and uses 50 percent less energy than if built simply to code. It's massive, too: 360,000 square feet.

Passive house

There's also the passive house movement gaining followers in this country. The practice is reaching quite a fervor in Europe. A house at the Cleveland Museum of Natural History designed with no furnace has been completed and is already catching attention. The residence, which uses passive house design and technology, cuts its greenhouse gas footprint and utility costs to the quick. SmartHome Cleveland received a national attention. One story said: "Because the house is so well insulated, it can hold heat from sunshine, body heat, lights and appliances."

The idea behind passive houses is that they use 90 percent less energy than a conventionally outfitted home of the same size. This also could apply to commercial buildings, but most information I've seen seems to keep this trend firmly entrenched in residential construction, at least in this country.

Passive House Institute U.S. defines the concept this way: It's a "very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source."

The push is to carbon neutrality.

The Passive House Institute says in the past decade about 15,000 buildings, mostly in Europe, have been designed and built or remodeled to passive house specifications. It's a small number but could gain significant influence as others see the lifetime benefits and reduced operating expenses -- not to mention the ecological rewards.