New York City’s years-long quest to crack down on illegal short-term rentals is taking shape, with legislation further regulating home-sharing platforms just a month from coming into effect.

The proposed rules for Local Law 18, which place more onus on those renting out their own units than on landlords, have received full support from industry lobby group the Real Estate Board of New York, which said apartment building owners and managers have faced “significant difficulties” overseeing the safety and legality of short-term rentals run through sites like Airbnb.

In some cases, landlords acting as “whistleblowers” on illegal activity in their buildings resulted in their being fined for tenants’ actions, REBNY Vice President of Government Affairs Ryan Monell said in prepared testimony for a hearing held by the Mayor’s Office of Special Enforcement on Monday.

“The proposed rules will go a long way in solving for the challenges building owners and managers have experienced in recent years relating to short-term rentals,” Monell said in his statement. “Ensuring that the city can properly enforce its laws in this area is vital to providing New Yorkers with access to housing, ensuring building security, and maintaining the quality of life that permanent residents expect across the five boroughs.”

Specifically, the rules would establish what is known as “prohibited buildings list” — which would allow for property owners to inform the city that they do not want to allow short-term rentals in their buildings. The rules would also formulate a registry to monitor short-term rentals, but REBNY is also encouraging the OSE to create a formal process for which building representatives are told when a property or unit is registered for short-term rent.

The rules would also require the platforms verify listings on their site are legally registered, and outlines a penalty schedule specifically for those who breach the rules.

“Currently, OSE is only able to take enforcement action against building owners even if the building owner was not responsible for the listing, including when the building owner had provisions in the lease prohibiting such listing from occurring,” Monell said in the testimony. “As a result, the owners have accrued the penalties for the actions of their tenants, which could be tens of thousands of dollars.”

Opponents of platforms like Airbnb have long argued short-term rentals have worsened the housing crisis as landlords have sought higher profits available through short-term rentals in place of long-term leases. But at Monday’s hearing, hosts spoke out against the proposed rules.

“My Social Security and pension does not cover my cost of living and without this income from the short-term rental, I would not be able to pay my mortgage and I would lose my home,” Aimee Thrasher, a Queens-based Airbnb host, said at the hearing, according to Bloomberg.

New York is one of Airbnb’s biggest markets in the U.S., and Local Law 18 would introduce some of toughest rules for short-term rentals in the country. The sites have already been subjected to restrictive measures. Late last year, the city council passed measures for rentals shorter than 30 days, requiring them to share listing data and host information with the city, as well as for a host to be present in the property.

But as of May, the city had three times the number of short-term rentals than apartments for rent, according to AirDNA.

The fines for hosts could stretch to as much as $5K, and Airbnb could face $1,500 per breach. The OSE will consider comments and feedback from the hearing ahead of the laws coming into effect next month.