The Martha’s Vineyard Commission voted unanimously Thursday night to approve an expansion project for Shearer Cottage, the historic Oak Bluffs inn that has been central to the long tradition of African Americans vacationing on the Vineyard.

“Good luck. I hope you guys can make everything you want to happen come true,” commission chairman Joan Malkin told inn owners Eric and Carma Van Allen after the vote over Zoom.

The project will significantly renovate and expand the cottage, which Charles and Henrietta Shearer opened in 1912 as a place for African Americans to stay on the Island. The inn will be upgraded from six to 15 bedrooms, while the two-story main cottage will be gut-renovated and rebuilt with five bedrooms and a kitchen. A one-story building will be demolished and replaced by two separate structures. The project will increase the footprint from 3,000 to 9,000 square feet.

Island architect Chuck Sullivan designed the project, which was reviewed by the commission as a development of regional impact (DRI).

Two public hearings were held, in October and again in December.

Mr. and Ms. Van Allen are the most recent members of the Shearer lineage to own the property, which has been in the family since its inception. It is the first stop on the African American Heritage Trail of Martha’s Vineyard and is featured in an exhibit in the Smithsonian’s National Museum of African American History and Culture.

During deliberations Thursday, commissioners stressed the historical and social benefits of the project, but expressed concern over increased traffic flow.

“[The renovation] is a two-edged sword. It’s an imposition of expanding a commercial enterprise in the midst of a traditional neighborhood, but it is also making an important entity viable for the future,” commissioner Doug Sederholm said. “It’s an important part of the African American Heritage Trail and it has important cultural and historical benefits.”

Wastewater discharge was a main issue, eventually resolved by an agreement to install an innovative-alternative septic system and a requirement that the property be in active use for only eight months of the year.

In the end the MVC decided the waterwater plan was a benefit.

“Even with the additional bedrooms, it’s generally an improvement of the water quality from this project,” commissioner Fred Hancock said.

Before approving the project, commissioners painstakingly reviewed a series of conditions for approval, including those pertaining to wastewater, employee housing, heating and cooling and landscaping, among other things.

“We tried to be as thoughtful and as thorough as possible about what we were requiring, and what would be the consequence if what we were requiring wasn’t met,” Ms. Malkin said.

After the vote, the Van Allens expressed their gratitude to the MVC.

“I just want to say that we intend to make this body very proud with what we build,” Mr. Van Allen said.