UMass-Boston Chancellor Keith Motley this week said the university’s purchase of the Bayside Exposition Center is part of a “new phase” for the campus acting independently, while acknowledging the move took many in the community by surprise and led to “unavoidable fallout.”

In his annual State of the University address to students, faculty and staff, Motley made his most extensive remarks yet on the $18.7 million purchase, which is still being finalized.

UMass-Boston intends to use the 20-acre waterfront property for parking and academic space as the university breaks ground on three new buildings on its current footprint. The university has a 25-year capital plan, which includes $500 million in work on new and renovated facilities and added green space. Dorms remain on the far horizon and are expected to be built next to the Peninsula apartment building.

“Here is an opportunity to really engage with people from all segments of the community to think about how that property can be used to benefit the community, the city, and the work of the university,” Motley told a crowd of several hundred people inside the Campus Center. “It presents to us a moment in which the physical boundaries of the campus need not confine our thinking or acting in this regard.”

Motley said it was “fairly evident” community members were caught by surprise by the pending sale when it was first announced in February. “Some are still surprised that we would deign to move forward ourselves on such an ambitious project and not wait for someone else to do it for us. That’s okay,” Motley said.

“However, this should be an indicator to you that this is a new phase in the history of the university and a new approach to getting things done. We think and act collaboratively because ultimately it’s the right thing to do and because it is a part of who we are; not because we are afraid or unable as an institution to act boldly on our own. The University of Massachusetts Boston is a full-grown institution of higher education in the greatest city for higher education in the nation, and maybe even the world, and it’s taking some time for some entities in the city to fully appreciate that reality.”

Motley, who has served as chancellor of the Columbia Point campus since 2007, also acknowledged that there was “unavoidable fallout” over the purchase, leading to some people being a “bit nervous about our intentions.” “I have, however, remained consistent with the message that we are insistent about a wide and inclusive process of gathering input from stakeholders in this community,” he said.

The Bayside property has a 275,000 square-foot building and parking for up to 2,000 cars. Three adjacent properties, the Boston Teachers Union Hall at 180 Mt. Vernon Street, the five-story Bayside Office Center at 150 Mt. Vernon Street, and the Doubletree Club Hotel at 240 Mt. Vernon remain privately owned and are not be included in the purchase.

Referencing a two-year planning process to revamp the Columbia Point neighborhood that has come to a halt since the proposed sale of the Bayside, Motley said, “I am aware that there were plans in place to bring commercial development and retail to this area. Our goal is to lead and work with the community to make this peninsula a destination point for all residents of Boston, and visitors, as well as a point of high service to local residents and workers, not the least of which are our students and employees. I want to reiterate my unswerving commitment to this inclusive approach to envisioning the use of that acreage and the fact that this is an opportunity for campus and community to get it right. We will work with these stakeholders to surface the interests, fears, and concerns around the development of the property and garner input on its future use.”

The Boston Redevelopment Authority, with the help of a mayor-appointed task force, had been working on a master plan for the Columbia Point neighborhood, which includes the JFK/UMass MBTA station, the Synergy property, the Boston Globe, Channel 56 and Sovereign Bank, among others. A draft master plan recommends a system of new streets and connections and BRA planners say many of the recommendations could be carried over.

But the task force hasn’t met since the news of UMass-Boston’s move. Jessica Shumaker, a BRA spokeswoman, said the agency was evaluating how the move would affect the draft plan and waiting for UMass-Boston to finalize its purchase.

“We’re still evaluating the modifications to the plan based on community input,” she said. “At the same time we’ve been a little bit delayed because of UMass’s intent to purchase.”

Motley also announced that the university’s College of Public and Community Service was reopening for enrollment this fall. The college, where Mayor Thomas Menino was once a student, had faced troubles in recent years with enrollment and fighting over administrative leadership. “With the tremendous history and tradition that College of Public and Community Service has in our community, we are anxious to see the college and its alumni achieve great success out into our future,” Motley said.