Washington area renters are doubling up.While there are no hard statistics to be had, housing industry spokesmen say that a drop in home sales, increased apartment rents and growing unemployment have created a boom market for home sharing.

One indicator is the Metropolitan Washington Council of Goverments' fledgling "Operation Match" program, which has received more than 1,300 applications in six months from persons who want to share housing. While the number is small compared with the more than 500,000 renter households in the area, officials say the program took several months to gear up and that interest has been growing each month as more people learn about it.

The average sales price of a home with 30-year conventional 15 percent financing rose to $122,000 in April, with monthly payments in excess of $1,100, according to the Federal Home Loan Bank Board. That fact, along with the reluctance of some buyers to make long-term financial commitments now, have kept many potential buyers in the rental market, some housing experts claim.

At the same time, recent rent rises and rising utility prices have forced many renters to cope with rapidly increasing housing costs by opening their homes to other renters, said John T. O'Neill, executive vice president of the Apartment and Office Building Association of Metropolitan Washington. In addition, an increasing number of homeowners who are saddled with high mortgage payments also are opting to share their residences.

The median rent for a one-bedroom apartment in the area is about $300, which in some cases--especially when utility costs are additional--is more than many people can afford, O'Neill said, noting that rents have increased more than 75 percent here since 1974. Each time rents increase, more people are affected he said.

"The downturn in the economy has a lot to do with the doubling-up phenomena," O'Neill said. Classified ads for houses and rooms to share have "increased tremendously" during the last year, he noted, and private referral services and public placement agencies are experiencing a marked surge in activity.

"By sharing a house, I can afford to have accommodations and space I couldn't afford otherwise," said Dr. William F. Dent, who moved here from Seattle recently. A resident physician at Veterans Administration Medical Center in the District, Dent pays $300 rent a month to Connie Coolick of Annandale, who shares a five-bedroom house with him.

Coolick and Dent are part of a fast-growing group in the Washington area who are living with roommates in an effort to cut expenses.

Connie Coolick's Annandale home rents for $685, not including utilities, which is too high for her to handle on her own, she said. A single parent with three children, she works for Metro Business Associates, a local employment agency. The $32,000 a year she once earned has fallen to "about minimum wage"because of the rise in unemployment in the area and a drop-off in commissions for placing job seekers.

Nevertheless, she'd grown accustomed to her place--"a nice house in a nice neighborhood"--and determinded that she could keep it if she got a roommate, she said. Metro Roommates Inc., one of largest of about a half-dozen referral firms operating in the area, matched her with William Dent.

Dent said he'd rather be living alone, but the reality of surviving on a first-year resident physician's $17,000 annual salary forced him to turn to alternative housing. Before turning to a referral service, he began his housing search by looking for a rental unit in the District (with a yard for his dog) for under $400 a month, he said, but he was unable to find suitable, comfortable accommodations, even with the assistance of several real estate brokers.

More than 100 homeowners have been matched with renters seeking to share housing through "Operation Match," a home-sharing program begun late last fall under the auspices of the Metropolitan Washington Council of Governments. Local jurisdictions are sharing about $200,000 in federal funds to promote the availability of low- and moderate-income housing throughout the region.

"Sharing a home is probably one of the most difficult decisions a person can make," said Carole Klase, who owns Metro Roommates in Alexandria. "Many people are sharing now who never shared before," she said, noting that those who use referral services rather than the classified ads or bulletin boards to locate roommates often "are more comfortable" knowing that prospective tenants and landlords have been "pre-screened."

Klase said her business has increased "at least by 50 percent in the last several years," with many of her clients citing unemployment--or "impending unemployment"--along with heavy mortgage payments and overall inflation as their reasons for seeking roommates.

Klase charges clients with space to share $50 for a full year of service--departing roommates are replaced for the term of the contract. The fee to those seeking accommodations is $20 for one-time service, "which keeps the tenants from being so mobile," she said. She said most tenants pay about $275 per month in rent, including utilities--the "going rate for a clean, nice house" to share.

"We probably see from 20 to 25 prospective tenants per week," Klase said, noting that each week she rejects four or five applications from people who wouldn't be "suitable" as roommates--"like someone who would only live with another Aries." In addition to interviewing all tenant applicants, "we visit every home personally and meet the landlords," she said, noting that "we found out it's almost impossible to market a home we haven't looked at."

She said her firm's clients come from all walks of life and economic levels and that about half of the landlords own their own home. "We work with the elderly, as well as the young, straight and gay, black and white," she said.

She said that while some of the homeowner landlords are sharing space to help cover the high mortgage payments they incurred by buying a new home recently, other long-time owners are taking on roommates to raise money to renovate and maintain homes they have not been able to sell.

Another of Klase's clients, Robert Dilonardo, teaches religion at Bishop Ireton High School in Alexandria. Dilonardo said he found it "very expensive to live on my own on a teachers' salary" and that sharing a house with an Alexandria homeowner and two other tenants was "very much an economic decision."

Before making the move to Alexandria, "I was living alone in an apartment in Arlington and when it came time to renew the lease they upped the rent to about $275," which was about $100 more per month than he could afford, Dilonardo said. He now pays about $200 per month, including utilities, and enjoys the living situation, he said.

Nevertheless, "I'd rather be on my own," he added.

"Whole new groups are sharing now," said Betsy Neal, owner of Roommates Preferred on Capitol Hill. While people who don't like living alone have been sharing housing for decades, Neal explained, "in the last couple of years, with rents going up so high, people can't afford to live in the way they've become accustomed to."

In recent months, rents have fallen slightly because more owners and lessors began sharing space, and homeowners who couldn't sell have put their homes on the rental market, she said. In addition, she said, "people went through the fear thing--scared of losing jobs, scared of the economy," and wouldn't or couldn't pay high rents.

However, rents have firmed up again, and the average price for shared housing is close to $300 per month, including utilities, up from a top rent of about $175 per month in 1973, when her firm began operations, she said.

Neal now finds accommodations for about 1,000 tenants per year for a fee of $30, said David B. Anderson, a partner in the referral firm. In 1970, the firm placed about 700 tenants, he said.

Low- and moderate-income earners aren't the only ones seeking roommates, said Ella Murphy, owner of Execuserv Inc. in Greenbelt. Her five-year-old firm finds shared housing for up-scale professionals, she said, and "in recent months I've been swamped with calls."

While home sharing has probably contributed to the increase in the area's apartment vacancy rate from about 1 percent last year to about 5 percent now, there is a real need for people to cut back on expenses, said O'Neill of the Apartment and Office Building Association. The popularity of sharing "is a significant advent and I think it's going to continue," he said, noting that "everybody is trying to figure out how to live for a little bit less."

O'Neill said he was roundly criticized by housing industry officials a few years ago when he predicted that "the elderly would not be able to afford to live alone and would be forced to share housing" because of the impact of inflation.

Now, he said, "the value of shared housing" is becoming clear as thousands of people, including many with moderate-to-high incomes, are grouping together to find decent housing and save money.