Sep. 9--HOUSTON�Maybe after a while, watching baseball or football in air-conditioned comfort becomes old hat. Maybe, if you have three domed stadiums, it's easier to imagine life with only two. 

What else could explain talk of tearing down the Astrodome � the first climate-controlled sports palace, the "Eighth Wonder of the World," opened a mere 37 years ago in 1965? 

Economics, says Michael Surface, chairman of the Harris County Sports & Convention Corp., which owns a long-term lease on the county-owned Dome. With new Reliant Stadium next door (where the Cowboys play the Texans on Sunday night) and a new home for baseball downtown, Houston doesn't need the Astrodome for sports any more. 

Demolition won't be the first choice and is just a possibility at this point. "It has a historical significance that's worth preserving and, if it's economically justifiable, renovation versus demolition is definitely preferred," Mr. Surface said. 

Preservationists want it saved. "It has national historic... importance," said Ramona Davis of the Houston Preservation Alliance. "It's right up there with Mount Vernon... It was an architectural and engineering marvel when it was built. It set a lot of firsts." 

Ideas for reuse include a Dome hotel, exhibition space or parking garage, all needed though feasibility hasn't been fully worked out. 

It might take awhile to decide what to do, Mr. Surface said. 

"You might find if we don't come up with some sort of solution in the next couple of years, the decision might be made to board it up but continue to pursue a redevelopment plan," he said. 

Redevelopment is crucial because the Astrodome costs taxpayers an estimated $1.5 million annually to keep ready for use, $500,000 a year in mothballs. "It's a wonderful facility, but it's one that needs to be used heavily," said Harris County Judge Robert Eckels. 

Even tearing it down would be costly, said architect Leroy Hermes, site planner for the county-owned complex that includes the Astrodome. For one thing, the playing field is 30 feet below grade and demolition would leave a 500,000 cubic yard hole to fill. 

"I don't think support would be there to tear it down," Mr. Hermes said. "I really, truly believe there's a practical alternate use." 

As long as Houston was in the running for the 2012 Olympics, there was no doubt. Plans called for renovating the Dome so that track and field events could escape the summer heat. When Houston was eliminated last month, that purpose vanished. 

Baseball's Astros moved to the $250 million, retractable-roof Minute Maid Park in the spring of 2000. The Texans, the NFL's newest team, started play last month in the $449 million, retractable-roof Reliant Stadium. The rodeo moves there in February. 

High school football, monster truck rallies, corporate softball games and the like are booked at the Dome through 2003. Yet-to-be decided events are planned in conjunction with the 2004 Super Bowl, to be played in Reliant Stadium, said Shea Guinn, who markets the place. 

After that, the Dome's calendar is empty. "The current use of the Astrodome, as people know it, is going to end within the next 18 months," Mr. Surface said. 

Decline in status has been rapid for the place. It's now known as the Reliant Astrodome because Reliant Energy agreed to pay $300 million over 32 years to name the complex that includes the old and new stadiums, a convention hall and a smaller arena. 

As recently as 1996, Houston regarded the Dome as high-tech, cutting edge. Then, Bud Adams, owner of Houston's original NFL team, the Oilers, declared it obsolete and moved his team to Nashville, renaming it the Tennessee Titans. 

Since then, Houston has spent more than $850 million replacing its professional sports venues, counting the still-under-construction downtown arena for basketball's Rockets. Businessman Bob McNair spent an additional $750 million to buy a new NFL franchise. 

No other city has spent that much money that fast to restore its status in the sports world � and the county still owes $58.7 million on a Dome expansion done in the late 1980s in a vain attempt to keep the Oilers happy. 

Being a three-dome city had appeal while bidding for the Olympics, but it only works long term if each facility makes enough money to pay the bills. It's not clear that the Astrodome can because "there's not enough events," Mr. Surface said. 

Architects find the renovation and reuse problem fascinating, and competitions have resulted in numerous proposals, some outlandish: ski slopes, water parks, aquariums, the world's largest indoor flea market. 

According to one proposal, the 7.5 acres in the cool, dry clime of the Dome is some of the most valuable real estate in semi-tropical Houston. Architects Larry Albert and Kerry Whitehead suggest selling the space, lot by lot, and building AstroCity, a town under glass. 

There's irony in the push to save the Dome, since critics in the past have panned it as a symbol of sterile, air-conditioned, automobile-dependent living. Houston has a tradition of tearing down buildings that have outlived their usefulness, no matter how historic. 

"It would be an extreme irony," Mr. Albert argues, if Houston � rejected for the Olympics partly because it lacks international appeal � tore down one of the few Houston buildings known around the world. 

But neither sentiment nor pie-in-the-sky ideas will drive the ultimate decision, said Mr. Surface, who personally favors making the Dome a high-end hotel with indoor parking. 

"I'm a numbers guy. The community deserves the opportunity to see... can it continue to have a future in some redevelopment," he said. "That's our first goal, but not at all costs." 

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