Three years ago, the proposed use of waterless urinals in the Comcast Center let loose a stream of labor indignation that threatened the tower's status as America's tallest green building.

Get ready for some real commotion.

Gov. Rendell is pushing for Pennsylvania's legislature to enact a state building code that would require environmentally friendly, energy-efficient construction. Whether he wants both residential and commercial development included is not yet known.

Rendell was short on specifics in his call for a green building code, which he made ever so briefly in his Feb. 4 budget speech.

In a 20-page address that outlined and defended a $29 billion state spending plan, Rendell's building-code pitch consisted of just one paragraph.

"Buildings account for 40 percent of our energy use; they consume 72 percent of our electricity, emit 38 percent of our CO2 emissions, and use 13.6 percent of our water," he said, citing national data from the U.S. Green Building Council. "If we are going to become energy independent and reduce greenhouse-gas emissions, we need to push the envelope on conservation. A green building code does exactly that."

That the topic was even in the speech was a surprise and a thrill to Nathan Willcox, an energy and clean-air expert at PennEnvironment. The advocacy group is drafting legislation for a state green building code and trying to line up sponsors for it.

Willcox said the bill was likely to include incentives - if not a flat-out requirement - for energy audits for existing buildings whenever they are sold. As for eco-friendly features that would be required of any new building or major renovation? Willcox said he favored allowing developers to choose from a menu of options - such as green roofs, solar panels, geothermal heating or floors, and carpeting made from recycled materials.

"It's not about setting some unattainable goal," he said. "It's about setting a minimum standard to make sure the majority of buildings are meeting some energy standard."

California is believed to be the only state with a green building code. In New Jersey, legislation was passed about a year ago that called on the Department of Community Affairs to "prepare . . . and make available to the public a green building manual for the purpose of ensuring that standards are available for those owners and builders who participate in any program that encourages or requires the construction of green buildings." That manual is in the works, DCA spokesman Chris Donnelly said last week.

In Philadelphia, Councilwoman Blondell Reynolds Brown said Rendell's call for a green building code "adds credibility" to her own legislative agenda. A year ago, Brown introduced a bill in City Council that would require any construction, extension, or major renovation of publicly funded buildings of at least 10,000 square feet to include features to qualify the structure for certification by a U.S. Green Building Council rating system known as LEED. That stands for Leadership in Energy and Environmental Design. Hearings on Brown's bill are expected next month.

"It behooves municipalities to look at nontraditional, innovative measures to cut our energy costs," Brown said, noting that utility bills in this region were expected to rise - as much as 30 percent by some estimates - as rate caps are lifted over the next two years.

But in Harrisburg, the graveyard is vast for many well-intentioned bills.

A state green building code has potential for a similarly grim outcome, said Shari Shapiro, a lawyer and green building expert at the firm Obermayer, Rebmann, Maxwell & Hippel L.L.P. At the very least, she foresees "a lot of hurdles" to passage.

Foremost is the state's Uniform Construction Code, which sets a building standard that applies across all municipalities, with some exceptions. Municipalities can require of builders more than the code does if, for instance, they can prove a health and safety concern specific to the municipality.

Shapiro does not believe green building requirements would meet the threshold of a health and safety issue unique to a certain municipality. One way around that, said Shapiro, who represents developers and advises municipalities, would be to alter the Uniform Construction Code to include green building requirements.

"The difficulty with that [is] there will be entrenched people that do not want changes to the building code," Shapiro said. "They do not want to have more stringent requirements."

The building industry is taking a wait-and-see stance on Rendell's green building code proposal.

"It's too soon to comment at this time because the details are lacking," said Scott Elliott, spokesman for the 9,000-member Pennsylvania Builders Association.

As an organization, Elliott said, the PBA "is supportive of green building efforts - in part because consumers increasingly are asking for homes that are more earth-friendly."

To foster a better understanding of what is meant by green buildings, Dewey Homes of Wayne has just finished building four model homes - one in Limerick, three near Coatesville. Each offers a different level of environmental sensitivity and energy efficiency.

Glenn Gleason, a senior vice president at Dewey, said the key to passage of any green building code would be financial incentives to offset the added construction costs associated with sustainable development. Green options can add $2,000 to $20,000 to the price of a home, he said.

Believing the way to encourage more green construction is "to lead by example," State Rep. Kate Harper (R., Montgomery) introduced a bill earlier this month that would require "high-performance" building standards for state-funded new construction and renovation projects.

At the Center City office of Citizens for Pennsylvania's Future, Christine Knapp, director of outreach, said "the debacle over the waterless urinals" in the Comcast Center - which was settled after the city plumbers union ultimately agreed to their installation - underscored the need for a green building code.

"That was a really perfect example of how hard it was to do green building," she said.