When Christopher and Janice Evans moved to the Washington area five years ago from Milford, Conn., they had only a week to find a house.

It was a dramatic, three-level contemporary house with lots of windows and skylights that lured them to Fairfax County. And while they've easily enjoyed the house, they say it's taken a lot more effort to enjoy Fairfax.

In their hasty search for a home, the Evanses, who are black, had not stopped to consider what life would be like for them in a county where blacks make up only 5.8 percent of the population, according to the most recent census statistics.

Despite the small percentage of blacks in the county, their numbers are growing rapidly, having more than doubled -- from 15,859, or 3.5 percent of the county population, according to the 1970 census, to 34,994, or 5.8 percent in the 1980 census -- as blacks have joined whites in the search for the middle-class, suburban dream. That growth has fueled their own questions about the role of blacks, both socially and politically, in the sprawling, mostly white suburban county.

"I miss the visibility of black role models for my children . . . . the black doctor, the dentist," said Janice Evans, a Fairfax County Public Schools social worker and mother of two.

"Even in the schools, they have seen only one black teacher, mostly blacks on the custodial staff, and no black administrators," said Evans, who for a year and a half drove her daughter, Tiffany, the 20 or more miles from Burke to Herndon so she could take dance lessons from a black instructor.

Pat Parrish/Blackwell understands the feeling. "Living in Fairfax is about getting into my car and driving to find my child a black playmate," said the Baltimore native and former director of the Fairfax County NAACP, who moved to Reston from the District 13 years ago.

For blacks in Fairfax County, there is a strong sense of being more isolated than blacks in other Washington suburbs. Several factors combine to cause this secluded feeling. Not only are blacks a small population in Fairfax, but they are spread throughout the vast county in tiny, isolated pockets, while Prince George's, Montgomery, Alexandria and Arlington have larger concentrations. Blacks make up 70 percent of the District of Columbia's population.

To gain more visibility and eliminate this sense of isolation, blacks are forming new networks, spurred on, they say, by the lingering momentum from the Jesse Jackson presidential campaign, examples of poor racial attitudes in the county's schools and a rally behind state Sen. L. Douglas Wilder, a black who is running unopposed for the Democratic nomination for lieutenant governor.

"What we're saying with these organizations is we don't have to take everything folks dish out," Parrish/Blackwell said. "We can decide what to put on our plates."

"We're finding out through these organizations that there are more blacks around us than we realize," said Christopher Evans, 42. "We're just so scattered, so isolated."

Janice Evans, who says she is more of a "joiner" than her husband, recently became a member of Black Women United for Action, a new organization dedicated to promoting more positive representation of blacks in the county.

Being one of three black American families in The Oaks, a neighborhood of 100 homes, the Evanses already are depending on some old-line networks to put them in touch with other blacks. They attend church in the District, but they joined the local branch of the NAACP, and put their children in Jack and Jill, a traditionally black organization that provides leadership training and cultural activities for children. The couple also belong to local chapters of their college social clubs.

"We're a county rich in black talent, but that talent is being underutilized," explained BWUC President Sheila Coates. "We have never had a black elected to any office in Fairfax County government."

"One of the real problems in terms of political strength for blacks . . . is that there are no massive, overwhelmingly black communities, where the power of black voters could control an election," said David Temple, chairman of the Mount Vernon District Democratic Committee and Northern Virginia coordinator for the Wilder campaign.

"This makes it difficult for minorities to win and to hold elected peole accountable," added Temple.

White politicians say they recognize how difficult it is for blacks to be elected to offices in Fairfax, so they have made some moves to see that there are black representatives on appointed boards and commissions.

"Where we have appointees, we have set aside a seat for a minority, usually a black," said County Board vice chairman Martha V. Pennino. There is a seat, designated for a minority, on both the Board of Education and on the County Planning Commission, she said.

But, Coates complained, "Every black on a list to be picked for something is from Reston. The people in Reston have more money and those in decision-making positions think that means better, higher quality, smarter." Coates, a third-generation resident of Chantilly, said that means most officials don't look to other parts of the county for black appointees or leaders.

Because there are not enough black voters in Fairfax County to sway elections, they will have to depend on coalitions with whites sensitive to their concerns, in order to have a voice in local politics, say blacks in the community.

"What you find as time goes on is that people are getting less and less color-conscious," said Pennino. "In the town of Vienna, with about a one percent black population, a black George E. Lovelace was elected and reelected to the council. It's going to take us all working together to make a change."

BWUC also will monitor the hiring of blacks in high-level county jobs, said Coates, noting that blacks hold just two of the 16 highest level administrative jobs in the school system and 10 of the 220 highest level positions in the county government. Although the Justice Department sued Fairfax County in 1978, charging there was a pattern of discrimination against blacks and women in county hiring and promotions, the highest-level positions were not contested in the suit.

Another reason for the sense of isolation blacks feel in the county, some blacks said, may be the new eparation between classes of blacks.

"There is a clear dichotomy between poor and middle-class blacks , which is no different than what is practiced by upper and middle-class whites," Parrish/Blackwell said. "But it is unique for the black community because we have prided ourselves on public unity.

"Many of the blacks moving to Fairfax are much more comfortable at the country club than at the community centers, so now we're having a lack of communication between the two groups."

Fairfax blacks, by location, are also isolated from blacks in other Washington suburbs. There is some interaction at churches and through clubs, but Roscoe R. Nix, president of the Montgomery County NAACP, said of the black community in Fairfax County: "I don't know much about that community because I don't hear about it. It could be because it's such a small community or it could be location."

It's too early to know what impact new networks such as Black Women United for Action will have in bringing Fairfax blacks together, to eliminate the sense of loneliness and allow them to work toward common goals.

"We've got to try," said Coates. "We realize change doesn't come easy."

Meanwhile, some blacks wonder daily about their decision to live in Fairfax.

"There's a lot to be said about getting to know a place first," said Janice Evans.

"I wanted the house in the suburbs and the station wagon with the wood on the side," Parrish/Blackwell said. "I bought too heavily into the American Dream."