NEWPORT, R.I. — A plan to build a $4.2 million welcome center at one of Rhode Island’s biggest tourist attractions, The Breakers mansion, hit a roadblock this week when the Newport Historic District Commission rejected it amid concerns that it is not appropriate for the historic mansion’s grounds.
Tuesday’s vote was 4 to 3 against the plan. The Preservation Society of Newport County, the nonprofit that owns The Breakers and several other of Newport’s most spectacular mansions, said it would appeal to the zoning board.
The society announced its intention to build the welcome center in April. It said a 3,750-square-foot, one-story building would give the mansion’s 400,000 annual visitors a place to learn about The Breakers, other mansions in the area, and city attractions. It would provide people with a place to get snacks and to use wheelchair-accessible restrooms. Currently, restrooms are in a portable trailer and tickets are sold out of a temporary ticket booth.
‘‘Creating an improved visitor experience with a permanent welcome center will help to sustain the financial success of both the Preservation Society and the Newport economy,’’ the group said when it announced the plan.
The society also said the project would allow it to restore some of the original character of the landscape at the entrance to The Breakers, which was built by Cornelius Vanderbilt in the 1890s.
The group has received $3.5 million in pledges for the project, according to Trudy Coxe, the group’s chief executive officer and executive director.
But some neighbors voiced concerns about building on the grounds of the 13-acre property, with some during Tuesday’s meeting suggesting the center be built across the street at the Breakers parking lot, according to The Newport Daily News. The newspaper also reported that Committee Chairman John Shehan, who voted against the proposal, said it was the intention of Cornelius Vanderbilt and his landscape architect that there be no buildings on the grounds other than the mansion, caretaker’s cottage, and children’s playhouse.
Shehan declined to further comment on Thursday, citing the Preservation Society’s intention to appeal.
Donald Ross, chairman of the board of the Preservation Society, said in a statement that the group had previously received approval by the Rhode Island Historical Preservation and Heritage Commission, and that it believed the city commission had erred in how it reached its decision.
‘‘We anticipate the zoning board will give our proposal an equally rigorous review and that it will affirm our position,’’ he wrote.