It's just a matter of time before construction cranes transform the rundown buildings and parking lots along Second Avenue between Pine and Pike streets. The location is just too good — a short walk from Pike Place, Benaroya Hall and a lot of the city's choicest shops, restaurants and office towers.

The questions are what shape the new buildings will be and what they'll do for the street and Seattle's skyline.

Two Seattle developers with deep downtown roots have each proposed to build a condominium tower on Second Avenue that would be among the city's tallest residential buildings — and, at 400 feet high, nearly two-thirds taller than what the city currently allows.

The extra height would be allowed under new downtown zoning changes backed by Mayor Greg Nickels and expected to be voted on by the City Council later this year.

Their proposed new towers, which would be across the street from each other, would bring about 1,000 residents and new retail storefronts to a section of downtown between Pike Place and Westlake Center that is overdue for a makeover.

The zoning change could accelerate a wave of development already under way by effectively making condos more profitable. The additional 12 to 15 stories permitted under the new rules would create units with views, which are easier to sell.

Supporters of the changes say it's also about better design. In exchange for the extra height, towers built under the new zoning rules would be slimmer and spaced farther apart, they say, allowing more light to reach the street and perhaps providing room for outdoor cafes.

The two developers have spent most of their careers working in downtown Seattle. One is Greg Smith, whose family has been active in Pioneer Square real estate for more than a century. The other is William Justen, a former city planner who oversees one of the city's choicest portfolios of historic buildings for the nonprofit Samis Foundation.

Smith and Justen are not the only developers hoping the City Council approves the zoning changes. At least half a dozen other high-rises have been proposed for the Denny Triangle area, and most are on hold pending the decision.

"The choice is, we can have maybe 12 short, squat buildings or we can have about 12 tall, slender buildings," says Justen. "It's just a nicer approach."

Fear of heights

But is Seattle really ready to get over its fear of heights? The last big wave of skyscraper construction in the 1980s led to a grass-roots revolt.

In 1989, over the objections of city leaders, Seattleites voted 2-1 for an initiative called the Citizens Alternative Plan (CAP), which capped building heights and tried to limit the growth of the downtown business district.

Since then, the initiative has been amended but not overturned. Office buildings aren't much higher than 40 stories, and the typical downtown residential tower is 12 to 22 stories.

Belltown, the downtown area's biggest residential cluster, was built under zoning rules that keep buildings relatively short and wide, resulting in a "table-top" skyline.

One example built to the existing rules is Cristalla on First Avenue, a 240-foot luxury condo building completed earlier this year. The elegant design makes use of a historical facade, but it's a rectangular monolith that fills its lot to the sidewalk.

City rules "kind of force you to create a box," leading to uniformity and darker, more canyon-like streets, developer Greg Smith says.

In Vancouver, B.C., by contrast, tall condos have been allowed to shoot up over a wide area, creating a more varied skyline and a more densely populated downtown. Vancouver, about the same size as Seattle, has three times as many people living downtown.

But at least one key leader, City Councilman Peter Steinbrueck, has questioned whether Vancouver should be a model for Seattle. Steinbrueck is chairman of the council's urban-development committee, which will hold hearings on the proposed zoning changes.

Steinbrueck has said he's worried about allowing buildings downtown that would cast longer shadows or visually overpower historic buildings. He has hired two well-known Vancouver planners to study the proposed changes.

A leader of the CAP initiative, Steinbrueck has served as one of its guardians since being elected to the council.

In 1998, he helped beat back an effort by then-Mayor Paul Schell to allow taller buildings. But after initially objecting, Steinbrueck eventually went along with Nickels' proposal to allow taller buildings along Broadway in Capitol Hill.

The proposed downtown rules would allow residential and commercial buildings up to 700 feet in the downtown office core, where the tallest towers are clustered. That's 300 feet higher than existing rules allow but well below the 937-foot-tall Bank of America Tower.

But the real battleground may be the city's mixed-commercial zone — which includes much of the Denny Triangle, areas of Second and Third avenues south of Belltown, and several blocks along the northern border of Pioneer Square.

In those areas, where building heights are limited to 125 feet in some cases, commercial buildings could go to 240 feet and residential buildings to 400 feet under the new rules. Planners hope the additional height encourages developers to turn some of the Denny Triangle's parking lots into housing.

With the new rules, Justen's and Smith's projects could be 67 percent higher than the Cristalla nearby. In exchange, they would have to be thinner above an 85-foot-high base.

The towers would have to be spaced 80 feet apart, compared with no spacing requirement under current rules.

John Rahaim, the city's director of planning, says the new heights are part of proposed zoning changes that reflect years of study and deliberation by neighborhood groups representing downtown businesses and residents. The goal, he says, is to make residential development more attractive so that more people live downtown.

The state Growth Management Act requires cities to make room for growth in urban centers to limit suburban sprawl.

"Itching to go ahead"

While the new zoning has been in the works for years, the debate takes on some urgency this year because the real-estate market is so hot.

Real-estate investment funds in the United States, Europe and Asia are snapping up buildings, and developers have no trouble finding financial backing.

"We certainly have got developers itching to go ahead," said Matthew Gardner, a principal in the real-estate forecasting firm Gardner Johnson.

Nickels presented the zoning changes to the council in the spring, and Steinbrueck has said he thinks a finished proposal can be ready for the council before the end of the year.

But, Gardner says, it took three years before the council voted to allow taller buildings in Capitol Hill, and this set of zoning changes is more complex and involves a larger area.

Historian Walt Crowley opposed the CAP initiative in 1989 and says the effort to limit heights was misguided. But he says efforts to legislate good design have been fraught with risk, noting rules in the '60s and '70s to require outdoor plazas outside office buildings — plazas that often became windblown concrete deserts.

"We have a history of producing results that were not intended and prove less than desirable," Crowley said.

Over the long run, Smith contends, the entire Puget Sound area has a stake in Seattle's ability to accommodate residential development downtown.

"I'd be the first to say I think we should allow buildings to be as tall as we can in the city," Smith says. "There's 3 ½ million people in the four-county area, and over the next 100 years we're [expecting] another 3 ½ million. Most of the big tracts of land within the growth-management boundaries are gone. So where are we going to put all these people?"

Tom Boyer: 206-464-2923 or tboyer@seattletimes.com