The Martha’s Vineyard Commission voted narrowly Thursday night to approve an Island Elderly Housing expansion project in the Aidylberg complex off Wing Road in Oak Bluffs. But the approval came with a key condition: IEH must return to the commission with a substantial redesign of the building before it can start the project.

The vote was 7-5 with two abstentions.

“We’re voting to tell them to go build it but make it better first,” said commissioner Doug Sederholm said just before Thursday night’s roll call vote.

IEH wants to add a 7,000-square-foot, five-unit complex at Aidylberg, near where two other low-income elderly housing projects are already in use. Called Aidylberg 3, the new building is planned at the site of a circa 1900 home that was torn down without the required prior commission approval. The demolished house formerly belonged to Marguerite Bergstrom, a founder of IEH who died in 2003 and had gifted the lot to the organization. The project is being funded through town-meeting appropriated Community Preservation Act funds from all six towns, as well as private donations.

The commission reviewed the project as a development of regional impact (DRI), and during public hearings this spring, the design of the building came under scrutiny by commissioners who suggested changes in both style and energy efficiency.

Leaders at IEH declined the suggestions.

During deliberations Thursday night, commissioner Joan Malkin introduced a condition that IEH take the design back to the drawing board. The commission is now asking the applicant to come up with something smaller which incorporates elements of the demolished building.

“When we get a replacement structure we want it to fit in with the vernacular of the neighborhood, which in this case is a question of massing,” Ms. Malkin said. “And the other problem is some of the architectural details of it.”

Commissioner Ben Robinson concurred.

“It’s unfortunate that they didn’t take the opportunity that we gave them during the public process,” Mr. Robinson said.

Earlier in the week the commission’s land use planning subcommittee had unanimously recommended approving the project, reasoning that the need for affordable housing on the Island outweighed a poor design.

“As mediocre as this design is, especially given some clear issues that could have been corrected without a massive redesign, on balance the need for this housing is such that I did not feel comfortable designing things by committee,” said Mr. Sederholm, who attended the subcommittee meeting.

While acknowledging the housing need, Mr. Robinson said a few extra months of work would be worth it in the end.

“The housing crisis isn’t going to be resolved with these five units and it’s not going to be resolved in the next two-to-three months,” Mr. Robinson said. “So I think that a slight delay now to get a better architecture [design] in a really prominent part of Oak Bluffs . . . may be worth the extra two to three months of extra design work.”

The roll call vote to approve the project with conditions was as follows: commissioners Doug Sederholm, Fred Hancock, Jim Vercruysse, Brian Smith, Jeff Agnoli, Ben Robinson and Ms. Malkin voted yes. Commissioners Jay Grossman, Michael Kim, Greg Martino, Christine Todd and Trip Barnes voted no. Commissioners Kathy Newman and Ernie Thomas abstained.