As if conquering the Internet weren't enough, Google has a new wonder in the works: a space-age structure that could be the greenest office building of all time.

The building's informal plans, recently submitted to the Mountain View Planning Department, look like the stuff of science fiction: It's five stories tall with undulating surfaces, and stretches like a pretzel around three courtyards.

Google's submission to the city shows that major effort went into picking a concept after studying dozens of alternatives, with plans stating that the structure would "create a benchmark for sustainability and help define new standards for construction." Company spokespersons told the Voice the project is on hold for now, but city officials say that if built, it would surely become an architectural landmark.

In building it, Google wants to go beyond LEED platinum -- the highest standard for a green building.

"This is a living building that has no carbon footprint," said Yvonne Farrell, a LEED-certified architect on the city's Environmental Sustainability Task Force who studied the plans.

City staff members say they are eager to bring it to the City Council.

"The building design is extraordinary," said project planner Nancy Minicucci. "It is a defining building. All in all we're very pleased."

The 310,000-square-foot building would be located just east of the Googleplex on the northern nine acres of a former Shoreline Amphitheatre parking lot known as "Charleston East."

The design is based on a "courtyard circulation concept" which winds the hallways of the building around courtyards connecting to open spaces, including a park promenade between the building and the hotel-zoned site to the south.

The preliminary plan is the work of several architecture firms led by New York-based ShoP architects, which Google selected after a national search. The architects have created a physical model of the preliminary design, with people, cars and trees to show scale.

Some of the ideas behind the building, as described in the submitted plans, can sound fantastical. The plans claim, for example, that the building will "evolve" rather than degrade over time: "Typical building performance begins to degrade immediately upon completion of construction. In the Max Green model, monitoring and feedback allow the building to evolve as knowledge and information improve."

"That concept is how you are going to get the greenest building ever," Farrell said. "If you are around Googlers you know they are always striving. They do something, they get the feedback, they change it and they keep evolving. That's a very Googley concept. It's also a natural concept."

The site design, done by landscape architect Walter Hood, aspires to create a buffer between the Bay and the city's "industrial forest." So far, plans include an orchard just south of the building along Shoreline Boulevard. The green slope beneath the building not only hides a 20-foot-tall parking garage, where cars are stacked tightly on top of each other, but rainwater runs off the slopes into vegetated "bio-swales." From there it feeds green roofs, gardens and planters as part of a "run-off conveyance system that slows, cleanses and celebrates runoff prior to discharge."

The plans mention a design with consideration of the sun's path for natural light and integrated next-generation solar panels, as well as consideration of prevailing winds for a natural ventilation system.

A pedestrian bridge shoots off the building and across Shoreline Boulevard, providing easy access to NASA Ames and a huge new campus planned for 64 acres Google owns around Shorebird Way.

The package of information given to the planning department indicates that Google has ambitions beyond just building new offices. A map shows a mixed-use "urban center" and "transit node" surrounding the intersection of Shoreline Boulevard and Charleston Road (mixed-use developments usually involve housing on top of retail).

Google calls it the "McDonough Master Plan" after famous architect and designer William McDonough. Minicucci said the company hired him several years ago to come up with a vision for the area, along with work on the adjacent Shorebird campus.

Plans specify a maximum height of 88 feet -- just under the 94 feet of the former Alza building nearby. There are four stories in some areas above the 20-foot garage.

The building's cost would appear to be exorbitant, but Farrell disagrees.

"I don't think it's going to cost any more than it would to do a Class A style building for Google," Farrell said. "It's certainly going to cost less in the long run -- 10 to 20 years."

In an e-mail to the Voice, Dave Radcliffe, Google's vice president of real estate, said the project didn't make financial sense at the moment, even though the company reported unexpectedly high profits this quarter.

"We're focused on making the most efficient use of the space we have," he wrote, "and new construction at the site doesn't currently make the most economic sense."

But as Google reportedly grows by 100 employees per week worldwide, it's only a matter of time before a new building becomes a necessity. The company already has started leasing the nine-acre site from the city for $1.7 million year.

"Charleston East remains part of our local development plan," Radcliffe wrote. "No matter what, we are still committed to long-term growth in Mountain View."

Minicucci said that once Google re-submits more formal plans, the City Council will hold a study session within 30 days.