Shortages of materials and increasing interest rates are endangering the housing recovery that reached boom proportions early this year, some industry analysts fear.

The demand for materials to fuel the upsurge in home building could put so much pressure on supplies, land and a labor force depleted by years of recession that prices could rise until they touch off another slump, said Barbara Alexander, an analyst with Smith Barney Harris Upham & Co in New York.

Rising interest rates on conventional loans and this week's increase of half a percentage point in interest rates on mortgages insured by the Federal Housing Administration and Veterans Administration may put the brakes on a housing recovery that already appeared to be faltering in recent weeks, say some.

"The issue is whether we are going to have a no-holds-barred housing recovery this year, in which case the escalation will carry the seeds of its own destruction, or whether the strength of the upturn will moderate just a bit, so that instead of a 65 percent increase in housing starts, maybe we will only have a 40 percent for the year," Alexander said. This "allows companies to do well and doesn't create the same kind of pulls on the supply of materials, land and, eventually, labor that a 70 percent increase would," she said.

Shortages in materials such as roofing and gypsum may result in "allocation in some parts of the country by later this year," she added. "This means that builders can't order all they want. It means that supply-demand will be so tight that the only way suppliers can handle" their sales is by allocating a certain amount to each builder.

"If we start off down the road of prices escalating rapidly . . . we could start the same wage-price push that we've been trying to get out of for two or three years. I think we will have building actually slow down a little," she concluded.

Mark J. Riedy, executive vice president of the Mortgage Bankers Association, contends that the pace of the housing recovery during the first three months of this year "tends to be self-limiting because of the need to scramble to get land" and supplies. "But these are not the seeds of its own destruction," Riedy said. "It just imposes restraints on growth."

Signs of a slowdown already are evident. Construction starts on new homes declined in April for the second month in a row, the Commerce Department reported recently. The April starts dropped to a seasonally adjusted annual rate of 1.49 million units, down 8 percent from the March level, which was in turn a 9 percent drop from February. April sales of new single-family homes dropped to 573,000, a seasonally adjusted annual rate, continuing a slide from the January peak of 611,000, according to the Commerce Department.

Resales of existing houses continued to climb, however, reaching a seasonally adjusted annual mark of 2.75 million units, the highest rate since December 1980, according to the National Association of Realtors. Also encouraging was the rise in building permits issued in April to 1.563 million units, a 7 percent increase from the previous month and the highest rate since September 1979, industry leaders said.

The permits are one indication "that the next couple of months will be heavy building months," said Kent W. Colton, executive vice president for policy, planning and economic research for the Federal Home Loan Mortgage Corp. "We will see some signs of price increases, but we ought not to panic. If things are really going to get out of hand, which I don't think they will, we will probably see signals in the next couple of months."

The signals already are mixed, and "at least four or five major indicators are clearly showing that housing is not going anywhere," according to Michael Sumicrast, chief economist for the National Association of Home Builders. NAHB studies show "a changed picture" in home sales, "particularly because of a worsening situation in the sales of condominiums and some downturn in sales of town houses," he said.

The studies show a 2 1/2 percent increase in home prices last month, "which would annualize at 30 percent," Sumicrast said. Much of the increase can be attributed to an "enormous increase" in lumber costs, he added.

The price of lumber was $264 per thousand board feet, a 14.8 percent increase over the price at the end of April and 55 percent higher than a year ago, Sumicrast said.

Last year's lumber prices were severely depressed, and the timber industry still is experiencing hard times. George H. Weyerhaeuser, president of Weyerhaeuser Co., said recently that the industry "is still economically terribly depressed." He said timber companies must raise prices by $70 to $100 per thousand board feet "to pay for the resource and to have some hope of earning a margin on the invested capital."

Alexander noted that timber and other building industries "mothballed a lot of the capacity during the market downturn. You don't get back up to 100 percent capacitizations. It takes quite a while, even up to nine months. You have to bring workers back, get new workers, some new ones . . . won't know quite as much. . . . "

Predictions of new housing starts for the entire year, from all segments of the industry, range from 1.3 million to 1.8 million. Alexander is forecasting "a little more than 1.5 million," she said.

"Even if we have 1.5 million starts, we will be up over 40 percent over last year. That's not exactly a shabby year. A four-year or five-year gradual economic recovery and gradual housing recovery would be far more positive for the consumer, business, almost any entity you wish to name than one that gets off to a roaring start, carrying the fuel for its own destruction," Alexander said.