A family-owned camp of small houses overlooking Stonewall Beach is set to be moved due to severe erosion.

The Chilmark zoning board of appeals voted unanimously on Wednesday to allow a house and several outbuildings to be relocated at the Langmuir property on Greenhouse Lane. The plan calls for demolishing a 1,100-square-foot home and building a smaller version of the house 500 feet back from the coastal embankment. Three small bunkhouses will also be moved.

The houses stand less than 10 feet from the cliff, with a deep fissure five feet from the main house. The new location of the house does not meet the 50-foot setback requirement; the zoning board will grant relief and also granted the Langmuirs permission to build the house 21 feet and 30 feet from abutting lot lines. The new house will be 920 square feet; the existing bunkhouses are about 500 square feet.

The new location for the structures is within 50 feet of a freshwater wetland. The Langmuirs have already received approval from the town conservation commission, site review committee and board of health. A building permit is still needed for construction of the new home.

This will be the third time the structures have been relocated over the years. The Langmuir house is the second relocation plan town boards have approved due to erosion in the past year. In February, the conservation commission ordered the removal of a neighboring home also on Greenhouse Lane, owned by Natalie Conroy.

Land surveyor Reid Silva presented the Langmuir moving plan on Wednesday. Mr. Silva said erosion hasn’t been as intense this past year, but the fissure and slumping is evident.

Mr. Silva said aggressive erosion for the cliffside is estimated at five feet a year, while the state coastal zone management agency estimates an average of three feet a year. With those estimates, the move could give the family up to 100 years in their new house.

“Who knows what’s gong to happen between now and then, but erosion will continue,” Mr. Silva said. “All of the shoreline houses will have to address it at some point.”

The bunkhouses will likely be dismantled and rebuilt further back, Mr. Silva said.

An easement has been granted by abutters and approved by the conservation commission for a new driveway off Greenhouse Lane.

The board praised the planning efforts and size of the new house.

“It’s very modest,” zoning board chairman Wendy Wheldon said. “It’s sad they’re tearing down that house, I love it,” she added.