Mark London’s to-do list after his last day heading the Martha’s Vineyard Commission includes painting, photography, spending time with his family — and finally applying for American citizenship.

On a sunny afternoon this week, Mr. London sat in his upstairs office in the Olde Stone Building near the Oak Bluffs Harbor, looking relaxed in sandals and a pink polo shirt. Only a few small paintings by his wife, Linda Thompson, remained on the walls, and some loose documents and folders lay scattered on a large wooden desk. Music by the Beatles drifted in from another office.

Thursday was Mr. London’s last day as executive director of the MVC, a position he has held since 2002, developing Islandwide planning initiatives and working to improve the public body perhaps most responsible for preserving the rural character of the Vineyard.

When Mr. London arrived at the office 13 years ago, he literally couldn’t walk in the front door. “It was collapsing,” he said. He leaves behind an improved building and a commission on sound financial footing, but also the long-term Island Plan, perhaps the centerpiece of his tenure. He has overseen several changes in how the commission itself operates.

“When I got here the commission didn’t have a website,” he said. “Planners did not have email at their desks. We didn’t have central server where all the documents are kept.” That has all changed, he said. A newly revamped website allows public access to about 5,000 MVC documents.

Mr. London redrafted the application process so developers could better anticipate commission requirements. “Now we have staff-applicant meetings right at the beginning,” he said. As was recommended 13 years ago, the various stages of MVC review have become more evenly balanced, with the full commission itself bearing less of the burden.

The mood among commissioners in 2002 was divisive, even fractious, Mr. London said. “I frankly don’t know if that was a long-term thing or I happened to arrive in the middle of the Golf Wars,” he said, referring to the fight over whether to develop an 18-hole golf course in Oak Bluffs. The plan was ultimately rejected. He described the current mood as collegial and collaborative.

“People tell me stories of 25 years ago, of very, very fractious meetings that went on until after midnight, and commissioners arguing with each other about some project,” he said. “And the meeting would be over, and they’d all go out for a beer together.”

One major improvement in the last 13 years had nothing to do with Mr. London or the commission. At around the time Mr. London started, Martha’s Vineyard Television began recording every MVC meeting and making it available online. Commissioners became more careful, Mr. London said, and local newspaper accounts finally began to agree with each other.

“Fifteen years ago you would read a report about a commission meeting in the two newspapers and you wouldn’t know it was talking about the same meeting,” he said.

During his tenure, Mr. London did not cast a single vote. Even at town meetings, he would sit in the back with other observers. He chose to retain his Canadian citizenship for 13 years as a way of underscoring his impartiality in the decision-making process.

But the MVC was still something of a rocky ride, he said, with public opinion often swinging between support and opposition. Support ebbed after the commission approved the roundabout in Oak Bluffs in 2012, although the opposition soon faded as traffic improved. Support grew in 2009 as the MVC rallied opposition to a proposed wind farm one mile from the Vineyard.

As the Island’s only regional planning and regulatory body, the commission exists on the edge of change. “All the controversial stuff ends up here,” Mr. London said. “And Vineyarders are known for having opinions.” Regardless of the outcome, he said, the public often ends up divided. When he took the job, commissioners jokingly suggested he wear a T-shirt with a bull’s eye on the back.

Mr. London was the youngest professional architect ever to graduate in the province of Quebec and he never stopped working. His earlier career focused on large urban redevelopment projects in Montreal. He and his wife, an industrial designer, also worked together on the original World Trade Center — he on transit stations and she on restaurants.

By the time they arrived on the Vineyard, they were well accustomed to Island life, having vacationed here for more than 23 years. But despite his efforts to remain impartial, Mr. London sometimes struggled to distance himself from his work. “It was more than a 9-to-5 job for me,” he said. “I’ve been coming here for three decades. I have a sense of commitment to the Island.”

His advice for incoming director Adam Turner, a native of Connecticut with three decades of planning experience: “Try not to take things too personally.”

Looking forward, he noted a rapidly growing population both on and off-Island that will likely drive Island property values even higher. “What does that do for the year-round community?” he said. “What does that do for affordable housing? Is this just going to be a place for extremely wealthy people to have a fancy house that they come to for a few weeks a year?”

The commission has helped preserve the Island’s rural character by limiting development, he said. “But there is a lot of development that has taken place and there is room for a lot more.” He also worried about global warming and the effects of rising sea levels.

Careful planning (and spending) could avert major changes in the landscape, he added. But some problems, such as increasing summer traffic, are harder to solve. “If you start changing the road network and widening roads, you change the character of Martha’s Vineyard.”

Mr. London will be on call this summer as Mr. Turner gets accustomed to the new role. But after that, he plans to spend some time away from the Olde Stone Building. People have suggested he join a town board, but those decisions will come later. The days of reading emails (about 75 a day), back-to-back meetings and late nights at the office are at an end.

Scrolling through his weekly schedule on the computer, Mr. London explained that the blue time slots were office work and the red ones were meetings. The proportions shift from day to day and week to week. “The month of September will be mostly playing with grandchildren,” he said.

Mr. London turns 68 in November. “I realized that a year ago I had missed my two-thirds-of-a-century birthday,” he said. Health issues over the last few years have provided a strong incentive to retire and spend more time with his family. One date he won’t likely miss is his 40th wedding anniversary on August 30, which happens to coincide with his last weekend on the job. He plans to take the day off.

“We’ll probably go to the Flying Horses,” he said.