New-home prices have been relatively stable for nearly a year; mortgage rates are down sharply from an all-time high, housing starts are 33 percent lower than a year ago and since mid-winter, many potential buyers have been putting off making decisions.

Then why -- in an area where the effects of the rrecession have been minimal -- has there only been slight improvement recently in the new-home market?

There's no simple answer, but local builders and people who sell houses for them cite these factors:

Potential move-up purchasers are frightened by the downturn in the general economy. They worry about being able to sell their present homes at prices they thought they should have gotten a year ago. They're still comforrtable in their present homes. So they're waiting.

Some people see mortgage rates as still being too high for their liking or ability to handle. (For some the higher monthly payments are too much, but others like the added tax deductions if they can meet financing requirements for income.) Some potential buyers think interest rates will decrease more. Others are gradually adjusting their thinking.

Other shoppers tell builders that they're waiting because of uncertainty about world and national affairs, including factors not related to housing: the hostages in Iran, the possibility of war, the high cost of gasoline, national leadership and the upcoming presidential election.

Generally, local builders say that interest rates make carrying charges too high for some pocketbooks. They hope interest rates will come down a bit more, believing that buyers are unable to sell exisiting homes and free equity to purchase a new home. Some potential buyers believe that the resale market is too depressed to put houses on the market now.

Unlike buyers in other big cities, Washington area residents are less worried about the general economy or losing their jobs or that their incomes will not keep pace with inflation. Nor are Washingtonians concerned that the prices of homes will tumble dramatically.

"Potential buyers should recognize that new-home prices have been nearly unchanged for six months or more but now we are getting to the point where prices will be higher for houses being started now," said John Dunn, sales manager of Hylton Realty Inc. at Dale City. House prices there are below the $88,990 median for new homes in this area.

Dunn said that sales are down 30 percent this year: "Many persons are still unaware that currently lower mortgage rates in the 11 1/2 percent range enable them to qualify for loans with two incomes," he said. Dunn said that after VA income requirements were raised in March, the agency reviewed the applications of 11 prospective Dale City purchasers (whose applications were turned down earlier), resulting in approvals for 10 who proved they could meet the monthy payments.

Builder Bob Mitchell, president of CI/Mitchell & Best, said that "almost all of the above" reasons have kept people from buying new homes for $145,000 and up. But he said that most of his buyers have to sell their own houses first. "That's the major hangup," he said. "Some are waiting for rates to come down."

Mark Rubin, western Maryland marketing executive for Pulte Homes, a large-volume builder in this area, said that 208 houses were sold in the first six months of this year at five Pulte subdivisions. He said his agents tell buyers that prices of houses and mortgage rates may go higher in the fall; "that they can't afford to wait."

In Northern Virginia, where the Scarborough Corp. built its first $130,000-and-up houses earlier this year, division manager Gary Garczynski said that the "meteoric" changes in mortgages rates shook up buyers. "The 11 percent range seems to be afffordable in this era," he said. "Prices are still going up on materials. Buyers are not afraid that the houses they buy will decrease in value."

Wes Hodgkin, who builds with a partner, Chet Cowan, in Potomac and Bethesda, said that some potential buyers are waiting for "that extra one-half point drop in interest rates that may not come." He said the firm is "starting some new homes (priced over $300,000) for fall delivery because things are looking somewhat better now."

While acknowledging that buyers find it harder to qualify for loans than 18 months ago when rates were under 10 percent, George Ford, marketing director of Wills & Van Metre Inc., said that the whole cycle of moves from lower -- to high -- priced houses must be put in motion again before the whole market improves.

"We sold six homes last week at three locations in Virginia and now we're starting more houses, after holding up for several months," Ford said. "Meanwhile, we've held profit to a minimum, despite cost pressures to raise prices as soon as possile."

In the view of Sam Borrow Jr., residential vice president of Kettle Brothers Inc., buyers are returning to the shopping market for homes but some ae delaying decisions "waiting for rates to come down more." But Barrow warned that prices of houses are likely to be higher if rates go below 11 percent this year, adding that Washington area new home shoppers also may be waiting for any new federal action to lower interest rates "because this is a national eleciton year."

Owners who need to sell their houses before they can buy more expensive ones often use bridge or temporary loans or guaranteed sales plans to facilitte their purchases. Routh Rrobbins Real Estate, a division of Coldwell Banker, is offering what its executive vice president, Robert Rathbun, calls a "credit card."

He said it shows that the owner-shopper will be assured a certain amount of cash, based on the value of the present house, to make a deal on a new house. "It doesn't cost anything until it is used. In turn we get business from the client who has assurance of being able to make a purchase," Rathbun said.

Meanwhile, HUD secretary Moon Landrieu recently told a convention of lumber manufacturers in his native Louisiana that "we look to a turn upward in home-buying by mid-summer and we anticipate a return to the annual level of at least 2 million housing starts by the mid-1980s."

Washington area builders thought interest rates of less than 12 percent would bring back buyers. Now they are hoping that something near 11 percent will do it. Yet, there is also a fear that mortgage rates may be bottoming and may start upward again in the fall. CAPTION: Picture 1, Scarborough Corp.'s Gary Garezynski, at Medford Leas house, says "meteoric" rate changes have shaken buyers. By Craig Herndon -- The Washington Post; Picture 2, Builders Wes Hodgkin and Cheg Cowen at a $300,000 house they are building. By Gerald Martineau -- The Washington Post