The Carnegie Library of Pittsburgh's new Hill District branch will not be a rectangle, and it has to be a one-story building. Other than that, plans are flexible and ideas are welcome, say Carnegie officials.

About 30 people gathered last night at the Irene Kaufmann Center to see early drawings and offer ideas. One man suggested performance space for jazz. Another suggested an outdoor component for nice days.

A series of community sessions continues today when library officials meet with the Hill House Community Collaborative.

Groundbreaking is expected at the end of the year on the northwest corner of Centre Avenue and Kirkpatrick Street. The space is shaped like a rectangle until Centre Avenue makes a curve. The building is to follow the curve, which creates an opportunity to create a unique entrance, said architect Rob Pfaffmann.

The site totals 19,815 square feet and includes three vacant commercial structures to be razed, including a defunct gas station and the former Eddie's Restaurant, which, legend has it, was a hangout of a young August Wilson.

The library is estimated to cost $3 million, of which about half has been raised, said Jane Dayton, assistant director of the Carnegie Library of Pittsburgh.

Joyce Broadus, manager of the current Hill District branch at Centre and Dinwiddie Street, has been gathering drawings from youth patrons for a portrait album called "My New Library," she said. "They are drawing what they want their library to be, and all ideas are valid. There's no idea that's too crazy."

Mr. Pfaffmann showed slides of other libraries, some local, some not, in which natural light has been used, sometimes at the exclusion of a need for man-made light. He showed how a children's area was made more cozy in the grand Homewood branch with an embracing set of curvilinear book shelves.

At the last community meeting, he said, people placed importance on a "transparency" between the outside community and library patrons, so people could look in and see the chess club, a regular gathering at the current Hill branch.

The new branch will be a green building, built according to LEED [Leadership in Energy and Environmental Design] standards, said Kim Kinder, an architect at Pfaffmann and Associates.

Some considerations include a green roof, water collection system, natural ventilation and "green" demolition of structures, reusing rubble and old fixtures, like bricks and stools from Eddie's, in the new building.