The appointment of David L. Scull to replace his mother, the late Elizabeth L. Scull, on the Montgomery County Council seemed assured yesterday because he packed some clothes and moved to his mother's home in Silver Spring.

Scull planned to spend the night at the home on Greyrock Road while his wife and daughter remained at their home in Chevy Chase two miles away. The move was necessitated by a county charter requirement that the person who fills Mrs. Scull's seat live in her Silver Spring/Takoma Park election district.

Five of the six council members indicated they plan to vote today for Scull to serve the remaining 18 months of his mother's term. Those who favor his appointment see Scull as maintaining the status quo on the council since many of his political attitudes are similar to his mother's.

Scull had asked the council if there were some way he could remain in his Chevy Chase home and receive the appointment, and some citizens protested his move to Silver Spring as "legal subterfuge."

Most council members said they did not see how they could free him from the residency requirement, and Scull said yesterday he is meeting with architects and builders with a view to renovating the 160-year-old Silver Spring home where he grew up and plans to have his family join him later.

Elizabeth Scull, who died May 29 after a nine-month battle with cancer, was seen as a liberal force on the council, on which she had served since 1970. Her husband, who died in 1968, had been a council member, and her father, Col. E. Brooke Lee, is regarded as the patriarch of the Democratic Party in Montgomery.

David Scull, 38, is a lawyer who represents the county's 18th legislative district in the Maryland General Assembly and is chairman of the county's House delegation. Like his mother, he is a Democrat and, like her, he is interested in ensuring a supply of housing for low- and moderate-income families in the county. He says he and his mother were "compatible philosophically in many things" but described himself as a fiscal conservative, which he said his mother was not.

Scull also is widely seen as a likely candidate for county executive in next year's elections. He has said he has no plans now to run but would be interested if the incumbent, Democrat Charles Gilchrist, is not a candidate. i

Council President Ruth Spector said she had initial reservations about Scull. "My concern is that whoever fills that seat would not spend time seeking higher office at expense of council work," she said. But she denied that those reservations were based on a concern that Scull would challenge Gilchrist, adding, "Charlie Gilchrist can take care of himself."

Council member Rose Crenca said she is opposed to Scull's appointment to the council, arguing that he is not a bona fide resident of his mother's district. She said party precinct officials and other citizens of the district are "a bit perturbed. I think there is a perception that there is too much wheeling and dealing going on."

Crenca said she wants other applicants for the job interviwed. By yesterday's deadline, these were Thomas E. Bratten Jr., assistant treasurer of the county Democrtic Central Committee, and Francies D. D. Alexander, a member of the health planning board.