One condominium tower plan has wind turbines fixed to its sides; one converts its wastewater to potable water using plants and organisms; and one forsakes common glass siding for a rough natural look of a rock cliffside.

Might Kakaako, where the state is directing dense residential high-rise development, one day sprout towers with such features?

The biggest developer in the area recently took in these and other ideas from potential future architects close to earning doctorate degrees in the field from the University of Hawaii School of Architecture.

Howard Hughes Corp., Kaka ako’s biggest private landowner with a master plan to remake its 60-acre Ward Centers property into Ward Village with 22 towers, engaged a design studio class this semester to simulate a real-world challenge to design plans for one parcel of its property and discuss ideas that possibly could be made real.

Nick Vanderboom, Hughes Corp.’s senior vice president of development, said School of Architecture associate professor Amy Christie Anderson proposed the idea "kind of out of the blue." The company, while surprised, was interested.

"It sounded like a great opportunity to interact with the students and the university," he said.

The task was to design part of a block slated for a public plaza and a tower site just Ewa of the existing theaters. The parcel could be part of Ward Village’s second phase following a first phase with three towers nearing the start of construction.

Anderson said it was a unique opportunity for her class of eight students who are in their fifth year of a seven-year doctorate program.

"There are a lot of things that haven’t been tackled before," she said.

Students worked on their plans all semester and received feedback from two local architects — Geoffrey Lewis of Geoffrey Lewis Architect Inc. and Kevin Miya mura of Urban Works Inc. — as well as Martin & Chock Inc. structural engineer Juan Morla and UH assistant professor of sustainable buildings and community design Wendy Meguro.

Final presentations that included two scale models and renderings were made to several Hughes Corp. executives earlier this month; they provided the students with a mix of praise, constructive criticism and experience selling their ideas to a major development firm in an early stage of executing a $7.5 billion plan.

Among the ideas presented was a ground-shifting design by Mark Anthony Tabuc buc, who envisioned rolling green hills rising through the plaza space up over his tower’s parking garage and leveling off roughly with the tower’s lowest floor several stories above the surrounding land base.

"I like the big idea," Vanderboom said. "I like the rolling hills to the tower. That’s a great concept."

Miyamura of Urban Works said the altered ground plane could pre sent interesting issues that test the application of Kaka ako building height limits.

Another interesting idea that garnered praise was a design element by Andreas Gaeta, who proposed a pair of towers on the site and sought to address an issue of people in one tower looking in on the living spaces of their adjacent neighbors.

Gaeta’s tower design alternated between two or three floors of living spaces and two- or three-level garden atriums on the inside face of each tower so that a living space in one tower always faces an atrium in the other tower.

A different use of high-rise garden space was presented by Noelle Yempuku, who designed two thin towers connected to a central elevator core by bridgeways that lead to garden spaces on every floor. To enter any unit, of which there are eight per floor, residents have to pass through a garden area.

Lewis, who is a visiting critic at the School of Architecture, called the garden element an exciting transition space.

Meguro, the sustainable building design professor, said entryway gardens would appeal to condo buyers. "I think it’s a huge sell," she said.

Not all the student ideas, however, drew compliments.

Phap Vu proposed covering his public plaza area with a giant wavy aluminum canopy with big holes to let in light while providing shade. This element was lauded, but the plaza grounds — largely open space around a platform circled by water and topped with a giant Ward Village logo sculpture (a W overlapping a V) — were panned as impersonal and uncomfortable.

Vincent Au included wind turbines high up in the spaces between three towers in his design as a way to generate electricity for the buildings.

Vanderboom was curious how much power might be produced. Au wasn’t sure, but thought it’d be enough for at least two towers. Meguro, however, said she’d be surprised if the five turbines in Au’s design would provide more than 10 percent of his proj ect’s electricity.

A different attempt at a green-building element, presented by Juliann Chen, appeared to have more potential. Chen’s plaza design included a natural wetland system called an eco-machine in which plants and organisms clean wastewater from her tower for recycled potable water use.

In a more aesthetic area, Matthew Kubota designed two towers in a teardrop shape where the narrow end of each floor is slightly fanned to one side above the floor below to create a sort of turning torso.

Alicia Kutkut-Arroyo also presented an eye-catching tower design by covering one side of her building with a concrete skin resembling a cliffside with openings for residents to look through like cliff-dwelling birds.

Lewis said works by famed Spanish architect Antoni Gaudi came to mind looking at Kutkut-Arroyo’s design. "It’s very artful," the architect said, adding that wrapping the heavy facade around corners of adjacent sides of the building could improve the look.

It remains to be seen whether any elements of the student designs get produced at Ward Village, or perhaps on other sites in Hono lulu by any of the eight would-be future architects who had what Urban Works principal Miya mura said was a great opportunity to work on an actual development site and get feedback from the site’s developer.

"I think we take a lot out of this," Race Randle, Hughes Corp. director of development, told the students after their presentations that constituted a final review of their design studio work. "Thanks for bringing some great ideas to the table."