With declining state funds and uncertain local planning period of dwindling enrollment, Montgomery County school superintendent Edward Andrews has recommended four construction and renovation projects in a modest capital improvements budget proposal that is unlikely to be fully financed.

Andrews is asking $22.9 million to renovate Wheaton High School, build the county's first regional vocational-technical center and to renovate Gaithersburg Elementary. His proposal also seeks reimbursement for a new gymnasium at Farquhar Middle School, and money to build an auditorium for Woodland High School.

A total of $15.1 million is being requested from the state's Public School Construction Program, 300 percent more than a preliminary recommendation from the state program's staff, which tentatively allocates $5.1 million for Montgomery County Public Schools.

"We recognize that the state may not have funds for our total budget request, but those four projects represent our minimal needs," said William Wilder, director of school facilities.

He said the budget process in the last four to five years has been particularly difficult because of decliing enrollment. This year's student population is 98,843, down from a peak of 126,311 in 1972.

"The uncertainty of school needs has placed capital improvement programs in a holding pattern for the most part. That's put us behind in our effort to modernize schools. We have a couple hundred facilities which are now five to 10 years older than when we began to look at the needs," said Wilder.

The current capital improvements budget proposal makes no mention of specific school renovations over the next five years, because a master facilities plan covering 15 years is to be approved by the board of education in the spring. The budget says only that modernization projects in the 1983-1987 period will include one senior high, one junior high and three elementary schools.

The vocational-technical center at Wheaton is the superintendent's top priority for fiscal 1982. It would cost about $13 million. That figure covers the cost of converting the 1,900-capacity school into one that would accomodate 1,265 students, and would house the vocational center in part of the building.

The second priority is a $2.9 million renovation of Gaithersburg Elementary, built in 1938.

"We have not talked about new schools in this budget," said Wilder. "We tend to forget in a period of slowdown in growth that some areas in the county are experiencing significant growth. We have crowded conditions in almost every school north of Rockville."

The largest sum the county has received from the state's public school construction program was $27 million out of a $32 million capital improvements budget in 1974.

The school board, County Council and county executive have scheduled a joint public hearing on the capital improvements program Dec. 1 at 8:30 p.m. in the Educational Services Center auditorium. The school board is expected to vote on the budget Dec. 9, and the County Council must act on the state-financed portion by the end of December. Council decisions on locally financed projects and the state assembly's action on state allocations are to take place in the spring.