Unlike many young professionals, Cecilia Cassidy has shelved her dreams of owning a home.

"I was priced out of the real estate market a long time ago," said Cassidy, 31, a newsletter editor who supports herself and a young daughter on "much less than $20,000 a year.

So when her apartment complex, Arlington Village, was sold for conversion to condominiums last year, Cassidy plunged into organizing the current effort to buy 98 of the 646 units through a limited-equity tenant cooperative.

That was one of many approaches discussed at a community forum on housing that drew about 180 Arlington residents to Thomas Jefferson Intermediate School last Saturday.

The conference, sponsored by the Arlington Civic Federation and a dozen other groups, also addressed the needs of elderly homeowners, housing discrimination, emergency shelters and landlord-tenant relations. But the central concern was the bleak future faced by lower-income residents in the high-priced, high-pressure real estate market that has developed in Arlington. h

Spokesmen for landlords and tentants agreed that shrinking profits and soaring energy and maintenance costs could decimate the supply of rental housing within a few years.

About 6,000 units, 40 percent of Arlington's lower-cost housing stock, have been converted to condo since 1972. Conversions and demolitions now planned "and those we are deeply suspicious about" could take another 4,000 units, Arlington housing services director Ed Brandt reported.

"No one can assure any renter in this county that your building won't be next," Brandt warned.

Aside from occasional flashes of anti-condo rhetoric, most of the workshops focused on the intricacies of tax policy, housing programs and legal tools that could be used to combat the economic trends.

Many forum participants endorsed using all or some of the county's "windfall" property tax gains from condo conversions, estimated at $12 million or more in added revenues since 1972, to help owners modernize aging rental complexes, increase housing subsidies and aid lower-income people displaced by conversions.

This concept got little support from most members of the county board, who stopped by for an informal lunch. Board Chairman Walter L. Frankland, for instance, said he "has problems? with the idea of "redistributing" property tax revenues.

Beside seconding Frankland's remarks, board members Stephen H. Detweiler urged an "economic" approach based on changing federal tax policies and increasing housing supplies.

Few others put much faith in construction. The cost and scarcity of building sites make subsidized projects "very hard," Lou Ann Frederick of the nonprofit Arlington Housing Corporation said later. One workshop did specutlate briefly about building housing on dilapidated shopping center sites or over the I-66 trench, but most emphasized shoring up existing rental housing and giving tenants more aid and leverage when projects are sold.

Several groups endorsed changing the federal tax law that now encourages apartment complex owners to sell to condominium developers instead of offering indivudal units directly to tenants.

Attorney Ira Lechner and many others gave top priority to a proposed "right of first refusal" law that would enable tenant groups to try to match any developer's offer for a complex.

Given that opportunity, Cecilia Cassidy of Arlington Village said a tenant cooperative might be able to buy units from a landlord for $15,000 or $20,000 each "and pay decent monthy rates" instead of paying a condo developer $25,000 or $30,000 per unit and bearing much higher monthy cost.

An inflated purchase price was one factor in the last-minute defeat of the cooperative plan advanced by Tenants of Marlo, Arico and Radnor Organization (TOMARO), Lechner said.

The prospects for help from Richmond were not regarded as great. A package of tenant-assistance bills sponsored by the Arlington delegation was buried in the General Assembly this year. "When we went down to lobby," forum moderator Charles Rinker recalled, "we found that some aides to key legislators didn't even know what a condominium is."

The Virginia Housing Development Authority also came under some fire because its housing subsidy ceilings are too low for high-cost areas. VHDA executive director John Ritchie Jr., who called Arlington's housing problems "the most severe in the state," told the forum that state assistance, while limited, may gradually increase.

The most difficult challenge, several people said, may be buying some time. Arlington already has "home-grown boat people who have been condo-ed out not once but twice or thrice," Lechner said. "If we talk for five more years, all the people we're trying to help are going to be gone."

An equally pessimistic thought came from Donald Bragg, 34, an insurance company auditor with three children and an income "somewhat below average" who rents a single-family home in North Arlington. Although he and his wife have tried to save enough to buy a home, "inflation and interest costs keep pushing it out of our reach," he said. Now their landlord is considering selling the house and has refused to renew their lease.

"We're not living uncomfortably, but we're living from month to month and if we have to move, we'll be priced out of Arlington," Bragg said. "I guess we represent the next wave of the problem."