The Fairfax County Board of Supervisor has expanded the county Housing Authority from seven to nine members, while refusing to reappoint the man who first proposed the expansion.

John C. Kershenstein, a controversial member of the authority and one of its frequent critics, failed to win reappointment this week when he received the lowest number of votes among five candidates for housing authority appointments.Kershenstein received only five votes from the supervisors, while the other candidates all received at least six. Last fall, Kershenstein had suggested the expansion in a series of proposals he made for improving the authority.

Supervisor James M. Scott (D-Providence), who led the anti-Kershenstein drive, said of his decision: "I did not feel he made the kind of contribution the other four members would make. I felt his year of service had been largely negative and that he was mainly interested in stopping construction of low- and moderate-income housing."

But board Chairman John F. Herrity (R), who originally appointed Kershenstein, said: "He was the first member of the authority to say what was wrong with it. There was a mess, and he had the guts to come out and say so."

Kershenstein had accused the authority of being too secretive and said it was not responsive to citizen concerns. But he defended his record on public housing, saying it was not the principle he opposed but the manner in which the Fairfax Housing Authority operated.