The Island Housing Trust has announced an ambitious plan to create 100 new affordable housing units on the Vineyard by the end of 2020.

The new plan was unveiled at the trust’s sixth annual summer brunch benefit, held Sunday on the grounds of the Lambert’s Cove Inn in West Tisbury. The plan would potentially satisfy almost half the Island’s short-term need for year-round affordable housing as defined by a housing production plan drafted this year.

“It just seems crazy when you think that there are as many houses as there are people that live here year-round on the Vineyard,” housing trust director Philippe Jordi told the 161 donors, board members and others who attended the brunch.

This year’s benefit raised $327,900, with additional donations expected in the coming weeks. Last year’s benefit raised about $400,000.

The new plan, known as Vision 2020, will cost $24 million and amount to more than a fivefold increase in existing trust projects. Mr. Jordi said the trust has already raised about $4.5 million in grants and donations (including for projects already in the pipeline), with Island donors having pledged to contribute $25,000 annually for four years. He said a $1.4 million goal for this year will be matched with state money.

Phillip Clay, professor emeritus in urban studies and planning at MIT, who also spoke at the benefit, said state and federal subsidies alone will not cover the cost of affordable housing on the Island. “There is no production without private donors,” he said.

He said the 600 year-round families and individuals on the housing trust’s wait list were likely just the tip of the iceberg. “We should remember that the 600 people and others are the very people that we rely on for our safety, for our beauty, for our convenience, and for our support during the summer,” he said. “That makes it an ‘us’ problem.”

Mr. Jordi said the trust has expanded its volunteer base, streamlined its administration and standardized its building designs and construction methods to reduce costs. He also said a new fund has been set up to allow the trust to buy property.

The Islandwide housing production plan sets a five-year goal of at least 223 new housing units, mostly rentals.

“Vision 2020 was a direct result of the recent housing production plan,” Mr. Jordi told the Gazette this week. “We really see ourselves as taking a leadership role in implementing what the towns have identified and set out as goals.” He added: “It’s ambitious, but our feeling is we have to be bold if we want to see the necessary impact.”

Trust board member, Aquinnah selectman and Wampanoag tribal member Juli Vanderhoop wrapped things up on Sunday by sharing her life’s journey as a commercial pilot who traveled the world and later returned to Aquinnah where she grew up.

“Bringing my children back here 12 years ago as a single mom, I wanted them to know this community,” she said. “I built a 10 foot wood oven outside and I began to bake.” (Ms. Vanderhoop’s Orange Peel Bakery in Aquinnah has gained wide recognition.) “And if you have an oven the size of mine, you invite the community to come in. And you break the bread. And you break these walls that convenience stores so inconveniently build.”

Picking up on the morning’s theme, she highlighted some of the things that make Martha’s Vineyard unique, including its fishing, farming and artistic communities. She also recalled a history of loss and resilience that runs through Wampanoag culture.

“When I think about things, I look back through my history and bring it forward. And I would like for people that I know —­ my friends, my family and my community that I love — to be able to remain on this Island.”