Khristopher J. Brooks Demonstrators calling for a freeze on rent increases this year gathered outside Cooper Union before tonight’s vote.

Rent prices across the city will increase 3.75 percent for tenants signing a one-year lease and 7.25 percent for tenants signing a two-year lease.

Members of the Rent Guidelines Board passed the increases by a vote of 5-4 Monday night during a meeting in Cooper Union’s Great Hall. The vote came at the conclusion of a raucous meeting during which dozens of demonstrators — many of whom chanted and held placards — called for a freeze on increases this year.

The increases, which apply only to rent stabilized apartments and lofts, take effect Oct. 1 and last until Sept. 30, 2012.

Based on the $1,700 a month average for studio apartments in the East Village, the increases approved by the board tonight translate into an average of $63.75 for one-year leases and $123.25 for two year leases. For tenants living in a one-bedroom, where the East Village averages $2,500 a month in rent, the average increases are $93.75 for one-year leases and $181.25 for two-year leases. Housing activists said after the vote that the negotiations preceding tonight’s meeting were slanted in favor of landlords.

An hour before the vote, scores of people gathered outside the Great Hall. Many of those in attendance had taken part in a rally organized by Tenants and Neighbors earlier in the afternoon.

Khristopher J. Brooks Demonstrators filled the Great Hall.

Immediately after the rally, demonstrators piled into the Great Hall for the meeting. In the weeks preceding tonight’s vote, the board had been considering an increase between 3 percent to 5.75 percent for tenants signing one-year apartment leases and a rise between 6 percent and 9 percent for those inking a two-year lease. But on Monday night, several board members proposed their own increases.

Adriene Holder proposed a 0 percent increase early in the meeting but it failed by a vote of 7-2.

Board member Steven Schleider also proposed an increase — 6 percent for one-year leases and 10 percent for two-years; it, too, failed by a vote of 7-2.

While board members batted proposals back and forth, those in attendance waved their signs vigorously. At one point, the crowd derided board members with chants of “Bloomberg’s puppets.” Meanwhile, a small group of landlords in the front row yelled back, “Don’t blame the landlords for this recession. That’s not the landlord’s fault.”

Finally, board member Brian Cheigh — who said that he sought an increase that was fair “in one of the worst recessions we may ever face in this generation” — proposed the increase that eventually passed: 3.75 percent for a one-year lease and 7.25 percent for two-year leases.

The crowded booed and roared as Mr. Cheigh outlined the proposal. Some stormed out. Then, with the room at the loudest it had been all night, the board voted 5-4 and the proposal passed.

Francesca Manisco, an East Villager who lives on Fourth Street and Avenue A and attended tonight’s meeting, said that she was dismayed by the debate and the vote.

Khristopher J. Brooks Demonstrators sought a freeze on rent hikes.

“All the board members are pro-landlord anyway, so it wasn’t a fair debate,” said Ms. Manisco, 48. “The two-year increase is way too much.”

Ms. Manisco, a minister and professional organizer, said she believes board members don’t realize that raising rent hurts more than just tenants.

“It’s going to affect our city because the more you increase our rent, the less we can afford to go to the hairdresser or out to eat,” said Ms. Manisco who has been living in her apartment for 31 years.

Ms. Manisco said 80 percent of her income goes to paying rent for her two-bedroom apartment. If rent increases any higher, she said, paying for her apartment will start to affect her grocery budget.

“I could only afford ice cream once a month,” she said. “Now, I can only afford it once every three months.”