BERKELEY -- The city's downtown is booming -- or just about to -- with a convention center, art museum, hotel and new apartments for thousands of residents either shovel-ready or on the drawing boards.

But will development cost downtown its historic character?

That's the conundrum panelists were asked to address at an noontime discussion last week at¿ the Berkeley History Center.

The event was sponsored by the Berkeley Historical Society and the League of Women Voters of Berkeley, Albany and Emeryville.

Panelists were clearly divided on questions of the consequences of development.

Planning Commission Chairman Jim Novosel, who is developing a downtown high-rise project at Shattuck Avenue and Berkeley Way, argued along with city Economic Development Manager Michael Caplan that development is creating a vibrant downtown.

But Rent Stabilization Board Chairwoman Lisa Stephens, a former member of the Downtown Area Plan Advisory Committee, and Becky O'Malley, former Landmarks Preservation Commission member and editor of the Berkeley Daily Planet, both expressed fear that development could, as O'Malley said, "detract from vibrancy."

Caplan and O'Malley squared off around the issue of density.

"I know that density scares people -- people worry about older buildings being overshadowed by new buildings," Caplan said. "By bringing people into a district, you're creating the economic vitality for other buildings. The more people live and recreate and visit an area, the more economic potential (there is to support) genuine landmarks."

O'Malley, however, contended, that the city is already dense and that increasing density doesn't always make sense. Building a residential tower near BART just so people can get to San Francisco doesn't necessarily enhance the city, she said.

Panelists sparred over plans for downtown high-rises. Measure R, approved in 2010, allows two towers up to 120 feet and three up to 180 feet.

The new towers would "destroy our skyline," Stephens said. Pointing to a 180-foot tower proposed as part of a project on a block southeast of the intersection of Allston and Harold ways, Stephens argued it would "dwarf one of our most beautiful buildings downtown" -- the historic post office.

Novosel described building height downtown as evolutionary. In the 1890s, downtown buildings were one to three stories; in the beginning of the next century they went to four or five stories; a 160-foot tower was built in the 1930s, and a 185-foot high-rise was built in 1960, he said.

"Those mark the skyline," Novosel said. "I do not find either of those (high-rises) offensive."

Novosel pointed to Measure R and its 65 percent approval as proof that citizens want "taller buildings in the skyline."

The audience, apparently largely siding with O'Malley and Stephens, responded loudly, "No, no."

Referring to Measure R's promises of historic protection, and environmental and open space enhancement, O'Malley called the proposition "a cleverly designed fraud to tell people that everything they dreamed of was going to come true."

Singling out the proposed development at Allston and Harold ways, she said, "The whole block that the Shattuck Hotel is on is a designated historic resource" that would be affected.

Former Landmarks Preservation Commissioner Carrie Olson expressed concern about the small shops, specifically Berkeley Vacuum and Ace Hardware, being displaced by development. "I encourage the city to save those resources for us," said Olson, who was among the 60 people who attended the event Tuesday.

Novosel, whose development will displace Berkeley Vacuum on Berkeley Way, said having a one-story building such as the one that houses Berkeley Vacuum a block and a half from BART is not appropriate.

"I hope to hell that Berkeley Vacuum moves down University (Avenue) where they can get a good deal on rent," he said. "I hope Ace Hardware also moves. This is the evolution of the downtown. If we were in the 1920s, you people would be yelling about all the log cabins being destroyed."