The Aquinnah select board Thursday pushed back against a proposed agreement amongst the up Island towns to split evenly costs of an $8 million renovation to the Howes House, arguing that Aquinnah’s use of the shared Up-Island Council on Aging building is lower than that of Chilmark or West Tisbury.

Plans for the Howes House, which houses the Up-Island Council on Aging in West Tisbury, have been underway since the spring, when West Tisbury voters approved more than $500,000 in design costs to renovate the building. A proposed funding formula for the $8 million project, modeled after the funding agreement for Tri-Town Ambulance, would have each of the three up-Island towns split costs for the renovation equally.

But Aquinnah select board members Thursday argued the proposal would unfairly burden Aquinnah, whose residents make use of the house least out of the three towns.

Board members agreed that the house is valuable to Aquinnah residents and worthy of investment, but said a new plan for funding will have to be worked out before the town can agree to pay for the project.

“There has to be a new figure,” select board member Tom Murphy said. “Because in my opinion right now, it’s not going to be anywhere near one-third.”

Also Thursday, the select board unanimously approved proposed changes to the Martha’s Vineyard Regional High School regional agreement, including a new funding formula for major renovations to the high school.

Under the agreement, Aquinnah would pay just 2.4 per cent of the cost of renovations to the school, which were recommended for Massachusetts School Building Authority funding in February. Other changes to the regional agreement include a reworking of the school census, a new budget formula and language updates such as changing Gay Head to Aquinnah throughout the document.

“The last time this document was amended was in 1994,” said high school special projects coordinator Sam Hart.

The select board unanimously approved the agreement, which will have to pass a town meeting vote in all six Island towns before it is implemented. The agreement is set to come before Oak Bluffs voters during a special town meeting on Nov. 1.

“Outside [the funding formula], there was just a lot of updates and changes,” Mr. Hart told the board.