WASHINGTON -- Even the National Association of Home Builders now concedes the housing market may be full of little tiny bubbles. And it's isn't champagne any longer.

Until now, NAHB chief economist David Seiders has steadfastly denied the existence of anything even remarkably close to a bubble in housing prices. Other than for perhaps a few hyper-inflated local markets, he has repeatedly said the overall market is in check, with wages rising pretty much in lockstep with ever higher house prices.

But at the group's Fall Construction Forecast Conference last month, Seiders seemed to agree with a rising chorus of other economists, saying prices could be in for a fall in many places.

Well, not for a fall, at least not per se. But they won't be rising nearly as rapidly as they have been.

"We're on the cusp of change," the economist said after a presentation by David Berson, his counterpart at Fannie Mae, who told the conference that 29 of the top 100 metropolitan statistical areas are experiencing price gains that are not sustainable.

"The plot is definitely thickening. There's no doubt about it," he commented following remarks by Mark Zandi, chief economist of Economy.com, who said housing is seriously overvalued in dozens of "juiced up" cities, many of which are "at risk."

Zandi has been humming that mantra for the better part of two years. And now Seiders appears to be joining in. "It feels like we're teetering on the edge," he said. "National price declines are no longer out of the question."

David Wyss, chief economist at Standard & Poor's, came close to throwing his hat in the ring, too, pointing out that the number of "seriously over-valued" markets has increased from 30 percent to "almost" half within the last year.

Historically, Wyss reported, the ratio of the average home price to average disposable income has been 2.6. But the price-to-income ratio is currently 3.2 on a national basis, and two to three times that in many cities, he said.

The "big, local" price bubbles are largely in high-priced coastal markets, he said. But "there is little evidence" of bubbles in the rest of the country."

In San Diego, for example, houses cost 9.68 times the average household income. In San Francisco, the ratio is 9.19. And in New York, it was 8.62.

These ratios "have to come down," the rating agency's top economist warned. And whether prices decline or continue to rise at a slower pace depends on the strength of the overall economy.

"The adjustment process probably doesn't involve price declines if the economy remains stable," he said. "If rates rise slowly, prices will stabilize and incomes will catch up. But if rates rise too fast, there could be a problem."

Still, Wyss stopped short of pronouncing a national price bubble. Until half or more of the largest markets become over-valued, he said, it is a regional problem, not a national one.

Maury Harris, chief U.S. economist and a managing director UBS Bank, said he doesn't see a major fallout, either. While "there is some uncertainty in housing prices," Harris said the market will slow, "but I don't see a crash."

Zandi, on the other hand, expects a "more severe adjustment." The economist said home sales will weaken first, than price gains will shrivel to 8 percent on average next year and a mere 0.5 percent in 2007, and finally housing starts will tail off.

Meanwhile, Seiders once again predicted the housing market will cool. Of course, he's done that for each of the last two years. But this time, even in the face of a fresh report of continued record housing starts, he assured an audience of builders, lenders, manufacturers and others that he's finally on the money.

"The market is plateauing (sic) off," the economist said. "I know I've said this for the last two years, but it now seems to be happening. This time I may finally be right."

If he is, total housing starts will slide in 2005 and 2006 -- but not by much.

Against a backdrop of slowing "but still good" economic growth plus slowing but "still pretty darn good" growth in payroll employment, starts will decline from an estimated 2.03 million this year, the best 12-month period in more than a decade, to 1.94 million next year and 1.88 in '07, according to the NAHB's latest forecast.

The fall off will be entirely in the single-family sector, as multi-family production -- both rentals and for-sale condominiums -- remains steady at 349,000-350,000 annually.

The forecast also calls for a drop in new-home sales, from 1.275 million this year to 1.215 million next year and 1.171 million the year after.

Those are still strong numbers, Seiders pointed out, they're just not quite as good as they have been. "Things continue to be very, very good for the housing market, but its role as an engine in the economy is coming to an end."