After a half century in his Mission District apartment, an eviction notice was the last thing that 87-year-old Guillermo Manzanares expected to get in the mail.

After all, for 50 years Manzanares had managed the property at 3421 20th St. A furniture restorer by trade and all-purpose fix-it man by inclination, he did everything from replacing toilets to painting to collecting the rent checks, which he would deliver each month to his landlord’s house in the Excelsior district.

In September, however, an investment group purchased the six-unit property for $1.5 million and quickly told Manzanares he was no longer the building manager. Not long after that came the eviction notice. The reason? The property owner said his lease forbade him from having roommates, although he had always shared the unit with family members and friends, including in recent years a caretaker who helps look after him.

In the words of tenant rights groups, Manzanares has been hit with a “gotcha eviction” — a category of breach of contract or nuisance eviction that has doubled since the real estate market started taking off in 2011. According to the San Francisco Rent Board’s Annual Eviction report, there were 2,120 notices of evictions filed for the year ending Feb. 28, 2015 — a 54.7 percent increase over five years ago. The number of evictions targeting tenants accused of violating their lease or causing a nuisance has doubled since 2010.

And this rise in evictions has led to a cottage industry that might be a new “only in San Francisco” — tenants’ rights boot camps.

At a time when creating new affordable housing tops the agenda at City Hall, city supervisors are scrambling to figure out a way to slow these evictions, which a recent Planning Department report showed are outpacing the number of new below-market-rate units being created.

On Monday, Supervisor Jane Kim introduced legislation that would give residents time to fix minor breaches of contract — “low fault” evictions for violations such as hanging laundry out windows or leaving strollers in the hallway. It would also give tenants an explicit right to have roommates, a measure that would have spared Manzanares.

“This eviction crisis is a tremendous handicap to the city being able to meet its affordable housing production goals — for every unit of affordable housing San Francisco builds, we lose two rent-controlled units,” Kim said.

The law would also require eviction notices to be written in languages such as Spanish and Chinese as well as English and list resources for tenants to help fight eviction attempts. “A lot of evictions are happening with monolingual tenants who don’t know their rights,” Kim said.

Landlords speak out

At a hearing on the legislation this week, dozens of small property owners complained that the proposed law would be punitive toward small landlords who already face steep taxes and regulations that favor tenants.

Landlord Andrew Long said, “There are so many things wrong with it I don’t even know where to begin. Allowing more and more roommates is unacceptable,” he said. “You are going to take perfectly nice buildings and turn them into slums.”

The small property owners at the hearing said the city’s pro-tenant laws are pushing local landlords to sell to out-of-town investors, who are paying top dollar for the buildings and are therefore more motivated to evict low-rent tenants.

“We pay the property taxes and for the bonds, but we don’t have any rights,” said landlord Sonia Ng.

Jay Cheng, deputy director of the San Francisco Association of Realtors, said the ordinance would also make it more difficult for landlords to crack down on tenants who are subletting through room-sharing services like Airbnb.

“Our position is that it’s an ordinance that is sloppily written and needs a lot of work,” Cheng said.

For tenants, the climate of fear is intense enough that tenants’ rights boot camps have popped up across town. So far, 21 neighborhood boot camps have drawn 700 tenants to cafes and bars from North Beach to Hayes Valley to Haight-Ashbury, said Dean Preston of the statewide group Tenants Together, which runs the sessions with the San Francisco Tenants Union.

Standing room only

On a recent weekday evening at the Mercury Cafe on Octavia Street in Hayes Valley, it was standing room only as about 30 renters, seven of whom had received eviction notices, listened to Preston talk about the explosion of evictions in the city and what tenants can do to ensure they are not the next renter displaced.

He explained that a landlord can’t evict them verbally or by text or e-mail, or enter their homes without 24-hour written notice. He said that landlords can’t refuse to make needed repairs, charge a punitive fee for late payment or evict a tenant who complains. He said tenants should study their leases, codify informal agreements in writing, and stop talking directly to their landlord if conflict arises.

Preston said he has been surprised that 80 percent of the tenants attending the sessions have not yet received eviction notices but are worried that day is coming soon.

“They are afraid of what they see happening to their neighbor and they want to protect themselves,” he said.

A Tenants Together survey of 1,300 residents of District 5 — which includes the Western Addition, Hayes Valley and part of the Fillmore — found that the majority of tenants are afraid of eviction, including 70 percent of tenants in Hayes Valley and 63 percent in the Fillmore.

“I can’t go to the park or a bar or a baby shower without somebody telling me about getting an eviction notice or harassed by a landlord,” said Housing Rights Committee of San Francisco member Sarah Sherburn-Zimmer.

Tenant attorney Cary Gold, who is representing Manzanares, said she has seen a huge increase in investors who hand out elaborate and often confusing “house rules” after purchasing buildings.

“There is a general sense of panic because every tenant feels like a sitting duck,” she said. “They know if they do get served with an eviction notice, they can’t stay in San Francisco. And most people can’t even afford to move to the East Bay anymore. There is really no place for people to go.”

Using legal tools

But landlords have their own tools. Eviction specialists like attorney Karen Uchiyama instruct property owners on how to clear buildings of below-market-rate tenants legally.

In a recent interview she spoke of tactics used by her client Anna Kihagi, who is being sued by City Attorney Dennis Herrera for allegedly harassing and intimidating her rent-controlled tenants to force them from their apartments. Uchiyama argued that the tenants being evicted by her client all were in violation, but conceded Kihagi buys buildings with “loose management and bad tenants” because they cost less.

“Some investors want move-in-ready, beautiful buildings with perfect tenants,” Uchiyama said. “Other landlords have no problem buying cheaper buildings with bad tenants because they are going to enforce the rules and be able to kick them out.”

Meanwhile Manzanares has been in the hospital but is on the mend and ready to return to his place on 20th Street. His daughter, Carla Anaya, said her father just wants to live out the rest of his days in his little flat off of Capp Street.

“He likes the Mission. He walks to pay his PG&E bill, to go to the bank, to visit his friends and the shops on 24th Street,” she said. “It’s very, very, very distressing.”

J.K. Dineen is a San Francisco Chronicle staff writer. E-mail: jkdineen@sfchronicle.com Twitter: @sfjkdineen