Concerned about the possible effect on the view, Mr. Pearsall said he worked out an agreement with the park’s landscape architect, Michael Van Valkenburgh Associates, acting on behalf of the park corporation, that mechanical structures were to be counted against that cap. Mr. Pearsall has email from Mr. Van Valkenburgh’s office memorializing the agreement.

The final environmental impact statement for the project, which was completed in 2005, confirms the height limit and, in the comment and response section, says the mechanical structures are included. But the general project plan, which came out the next year and is supposed to reflect the impact statement, mentions only the 100-foot cap. Last fall, as Pierhouse rose, Mr. Pearsall grew alarmed.

“It became totally apparent that the deal I struck was about to be breached,” he said. A prominent preservationist, Mr. Pearsall now sits on the city’s Public Design Commission, which has jurisdiction over everything from boardwalks to monuments to buildings on city-owned land.

He met with Regina Myer, who took over as president of the park corporation in 2007. He said she had apologized and had told him she was unaware of his agreement. In a statement, Ms. Myer said: “We always work hard to be responsive to the community on all park projects and it is regrettable that there was a misunderstanding in this case.”