HAYWARD — Architects on Monday unveiled two visions for a future main library in the downtown area, one that would retain the park surroundings of the current facility and one that would reside within a taller, more urban-style building on an adjacent lot.

"What I like about the current site is that it's like an arboretum, so beautiful," said Christopher Noll of Noll & Tam, the Berkeley architecture firm selected by the city in 2007. "On the other hand, the other site puts it into a much more urban context, closer to B Street and the downtown area."

Noll presented the two ideas Monday to the city's Library Commission. The panel recommended the urban model to the City Council in a 4-2 vote, with members Kelley Greenne and Lisa Brunner dissenting.

Pros cited for the winning selection: It could further rejuvenate downtown; be in close proximity to the city parking garage; allow for creation of a central park at the former site; and preclude relocation of the current library during construction.

"The lack of disruption is worth a lot," library Director Lisa Rosenblum said.

She said it would cost about $1 million to find and lease another place and move the collection back and forth.

But there's also a catch to the location: To build the new facility would require using not only the city's C Street lot, but also purchasing the parking lot of the U.S. Postal Service, which has its downtown Hayward branch next door to the site.

"It is not a given that we can do it," Rosenblum said. "If that's the library that we prefer, we can step up pressure on our federal representatives. The lot is definitely underused."

The city manager has made initial contact with Postal Service representatives but has not gotten very far, Rosenblum said.

Other problems with the recommended plan were raised, such as whether it is what the public would like to see. Greenne cited a survey from last year that found people enjoyed having their library within the park. But others said the poll results may have been different had the new plan been an option at the time.

If moved, the current facility would likely be razed and the site would become one large park. The family that deeded the land to the city included a caveat that it must be used for a free, public purpose, or be returned to the family, Rosenblum said.

Noll said he'd like to keep all the existing trees and convert the central area into a sloped public green, possibly with an amphitheater at one side.

However, some commissioners worried that increasing the size of the park would exacerbate the problem they have with homeless people "lounging there all day."

Noll said the current setup, with the building in the middle of the park, may be less desirable for safety reasons than a park that "police can see through."

"There are a lot of nooks and crannies in the current building that are out of sight," he said. "There might be less problems there if there are no dark corners."

Noll and Rosenblum both stated that they also prefer the new location.

"This is the opportunity to do something new, and it's rare to get that opportunity," Rosenblum said. "It's a creative plan for a city that needs some more help to make a downtown that people want to go to."

Eric Kurhi covers Hayward. Reach him at ekurhi@bayareanewsgroup.com or 510-293-2473.