In a speech laced with warnings, the city's new housing director told about 1,000 of his employes yesterday that their agency is "in the grave and we've got to jump out."

Robert Moore, who takes over Monday as the District's housing director, also announced that within 90 days rehabilitation will begin on some of the 400 boarded-up houses the city owns and said that some of the city's worst public housing will be cleaned up.

He gave no additional details, but said, "The people who help me do that will be with us the rest of the way. Those who are barriers will be gone."

Moore met with the employes at the New York Avenue Presbyterian Church and was joined there by Mayor Marion Barry, who made the housing department and its former director, Lorenzo Jacobs, a mojor issue during his mayoral campaign last year. Barry spoke only briefly and answered a few general questions.

Moore told the employes that he would hold them responsible for their conduct and performance but he also said that much of his stern message was directed at the supervisors.

"I don't fire clerks and maintenance people," Moore said. "I fire directors. I'm just passing it on because that's what the mayor told me."

Moore comes to Washington after serving for two years as executive director for the Housing Authority of Houston. He is a Howard University graduate who is also a former special assistant at the U.S. Department of Housing and Urban Development.

Moore takes over as housing chief at a time when the District has been a leader in the growing nationwide trend that shows middle-class blacks and whites rebuilding the inner city areas of older cities. The District is also in the midst of a major commercial and residential construction and rehabilitation boom and prices have been growing along with the new buildings.

Moore takes charge of a department with a $95 million budget. The department has been criticized for operating some filthy public housing projects, for submitting an unacceptable plan for finding new homes for people displaced by urban renewal, for filing unacceptable applications for federal grants, for spending only 63 percent of its federal community development funds and for maintaining a waiting list of 7,000 families for public housing, a list that has not decreased for years.

Moore said he had found "no sense of urgency" to tackle these massive problems as he talked to staff members in many of the department's offices this week, and toured 10 of the city's 23 public housing projects on Sunday.

"I want people who can work. I don't respect longevity unless it is tied to performance," Moore said.

"How you behave, your staff will behave," he said to the supervisors in the audience. "So if you're not getting to work on time you can't get on anybody else for being late. If you take a three-hour lunch you can't blame the staff for doing the same thing and if you don't make field visits" neither can staff members be expected to go out and meet the people the department serves.

And when clients are met, Moore said, "I expect you to get up and shake their hands and say I'm so and so and I work for the District government and I want you to do your utmost to help them."

"This is war and we should be on a wartime footing," he said to the obvious displeasure of some employes.

His employes wished him well but expected no immediate transfigurations.

"He's got a tough job. It's going to be tough unless they start firing some people. It's not going to change if they keep the same people they have," said one employe.

"He sounded good, but let's face it: There are a lot of problems," said a rehabilitation specialist "We've seen so many administrations come and go and nothing has changed It would be a feat if one person could come in and make changes after so many years."