The city is turning up the heat against operators of illegal vacation rentals, putting more inspectors in the field and scanning the Internet for advertisements.

With the recent addition of two full-time and three part-time inspectors in the field, the city has issued 12 notices of violation against bed-and-breakfast and transient-vacation- rental owners from Jan. 25 to Thursday, said Wally Carvalho, acting administrator for the Department of Planning and Permitting’s Customer Service Office.

Two of the notices were issued to property owners with recurring violations, which means they did not come into compliance within 30 days and likely will face civil fines, Carvalho told the City Council Zoning and Planning Committee on Thursday.

Those who are fined pay an initial penalty and then between $250 to $1,000 a day, Deputy DPP Director Art Challacombe said.

In all of 2015 the inspectors issued 37 violations, Carvalho said.

Traditionally, inspectors responded only to complaints, but now “we are checking websites to see if we can come up with … other information so we’re not only taking in complaints, we’re being proactive,” he said.

Carvalho said the two full-time and three part-time inspectors began in January and are on contract. The coming year’s operating budget is expected include funding to convert those positions into four permanent, full-time positions, he said.

Prior to 2016 DPP had 13 inspectors and one branch chief.

The Council last year earmarked $300,000 for DPP to hire inspectors to investigate illegal rentals in response to residents’ complaints about traffic, parking and noise.

The city stopped issuing certificates for B&Bs and TVUs in 1990, and currently there are about 700 legally on the books. But as many as 4,000-5,000 vacation rentals are operating illegally on Oahu alone, according to some estimates.

The news of increased enforcement was met with alarm by vacation rental operators who attended Thursday’s informational hearing.

Kailua resident Will Page said there’s been no scientific research to conclude that vacation rentals are the cause of increased traffic, parking and noise problems in Windward Oahu neighborhoods.

“There are something like 4,000-plus of these properties that are operating on this island,” Page said. “Do you intend to shut them all down? This is a $1.5 billion industry that is now accommodating about 15 percent of the tourism industry on Oahu, and you’re going to shut them down?”

Kailua resident Mark Caspers said there appears to be a mix-up in interpretations by different inspectors. He said that when he and his wife visit family members on the mainland, they rent out their house. While one inspector said it’s OK to rent out to one party for a few days within a one-month period, Caspers said he was later fined for doing so.

“We tried to do this legally by seeking counsel and talking to inspectors for the city,” Caspers said. When he called DPP for clarification, no one called back, he said. “So how am I supposed to find out what the real rule is when they don’t return calls?”

Challacombe and DPP Director George Atta said Thursday they will look into the situation but that to them the law is clear: Anyone can rent a unit for one month or longer, but shorter-term stays require the landowner to own a nonconforming-use certificate.

Tonic Bille, president of the B&B/TVU Association of Oahu, said there would be fewer problems if the city would make all vacation rentals legal and charge them permit fees. “Permitting and regulation are the resolution,” Bille said.

The loss of vacation rentals could result in the loss of hundreds of thousands of Hawaii visitors, she said.

A bill allowing a limited number of new legal certificates that came with strengthened enforcement was debated last year and then deferred by the Zoning and Planning Committee in June.

Zoning Chairman Ikaika Anderson, who has been trying to find middle ground on the issue, said he shelved the bill because it didn’t seem to be making anyone happy.

Vacation rental supporters said the measure offered too few new legal certificates, while opponents said no new permits should be allowed until the city begins enforcement in earnest.

After Thursday’s meeting Anderson said that even if he were to air a similar bill now, it would not get the support of a majority of Council members.

At this point, he said, “I’m waiting to see what’s going to happen” with the addition of the new inspectors.

For more about TVUs and B&Bs, go to honoluludpp.org/ReportsNotices/tabid/85/aid/5/Default.aspx.