Islanders filled a meeting room at the Casco Bay Lines waterfront offices Thursday evening to express their concerns over a renovation plan that will put the Casco Bay Garage elevator and one of two pedestrian stairwells out of service for five months.

About 25 people attended the meeting to learn more about the $600,000 project, which is scheduled to begin Monday.

Several officials from MHR Management, which owns 51 percent of the garage, presented their project plans at the meeting, which include providing a valet golf cart that will transport up to 6 people at a time to their vehicles during the construction period. The carts may also be used to transport luggage.

A total of 12 parking spaces for handicapped people – there are 8 spaces on upper levels now – will be available on the first floor of the garage and two “stork” spots for mothers and baby carriages will be provided during the construction phase, according to MHR general manager Steve Kalisz.

Most of those prime first floor parking spots are occupied by Portland firefighters and police officers, who will have to park on upper levels of the garage. The Portland fire boat docks at the ferry terminal.

“The project will be an inconvenience for the people who park there, no question about it,” said David Farmer, who was asked by MHR to moderate the meeting.

Phil Haughey Sr., a principal in MHR, said his company is trying to minimize the impact of the project by doing the heavy construction work during the winter months when there are fewer people traveling back and forth from the mainland to the islands of Casco Bay.

Haughey said repairs are needed to fix what structural engineers are calling cracks in one stairwell tower that could affect their stability during high winds or earthquakes.

When ferry users asked that the construction work take place 24 hours a day to speed up the project, Haughey said that would not be possible because of city noise ordinances. His staff pointed out that there is a hotel located across the street from the garage. Construction work will only be permitted to occur between 6 a.m. and 10 p.m.

Farmer said MHR’s management team met with city officials after the meeting and are planning to provide garage users with a list of changes to the project they hope will address some of the concerns raised at Thursday’s meeting.

“We thought it was a productive meeting,” Farmer said. “It was good to hear their concerns.”