LISBON — Superintendent Richard Green told the School Committee on Tuesday night that the new Lisbon High School gymnasium is scheduled to be completed by Oct. 21.

The $4-plus million project is expected to be finished almost two weeks before voters go to the polls a fourth time to approve a school budget for 2015-16.

The Town Council will decide whether to include unspent bond money from the gym project, or only the interest from the unspent money, in the latest budget. The School Committee wants unspent money from bond included in the budget.

Voters rejected a $14.93 million budget on June 9 and a $14.88 million budget on Aug. 11, with the majority saying each time that it’s not enough money. The third vote on Sept. 22 resulted in voters rejecting a spending package of just over $15 million.

The Town Council previously battled with the School Committee over whether the unspent money from building the gym should be put in the 2015-16 budget before the project was complete.

As the project came closer to completion, council members voted to have some of the money left from the project included as revenue in the budget. That put the September budget proposal slightly higher than those proposed in June and August.

In January, the Town Council told the School Committee it wanted a budget $600,000 lower than the previous year. The School Committee didn’t heed the warning and presented a flat-funded budget.

The School Committee formulates the budget and the Town Council has authority to decide what amount to recommend to voters.

On Tuesday, the committee agreed to have its legal counsel draft a letter to the Town Council about the legality of using more than just the interest from the bond proceeds in the 2015-16 budget.

The first reading of the amendment will be presented at the Town Council meeting and public hearing Tuesday, Oct. 20.

Also Tuesday, the School Committee voted 4-0 to accept bids from Downeast Energy for No. 3 heating oil at a fixed price of $1.889 per gallon and propane with a fixed price of $1.139 per gallon. The prices are good from Oct. 7, 2015, through Sept. 30, 2016.

The committee also voted to accept the bid from M.W. Sewall for Type I kerosene at a fixed price of $2.039 per gallon, diesel at a fixed price of $1.889 per gallon, off-road diesel at a fixed price of $2.009 per gallon, and gasoline rack prices plus 3 cents.

In other business, the committee approved:

* An application for a Berlin City Auto Group grant to buy two new computers for Lisbon High School;

* A Boston field trip for the fifth grade;

* An overnight trip to the University of Maine 4-H Camp and Learning Center at Bryant Pond for the fifth grade over two separate sessions in October; and

* An overnight field trip to Camp Kiev for Lisbon High School students.