Reported ArticleHousing

How Hidden Property Owners and Bad Landlord Patterns Are Revealed in NYC

Housing tools in New York City demystify building ownership information and help renters, policymakers, and housing advocates spot and address problematic landlord behavior. Could tech-savvy groups outside The Big Apple replicate these tools in their communities?

Photo by Scott J. Waldron via Flickr

When I type my Brooklyn address into New York City’s property owner search tool, the first result I see is an error message that says no records exist for my building. After several tries—substituting “street” for “st.” then deleting it altogether, then removing the apartment number—it finally returns an actual result: an anonymous LLC, with no other clarifying information.

A different website gives me a more helpful result on my first try: my landlord’s full name, familiar from the dozens of rent checks I’ve written him over the years. I can also see how many evictions have been recorded at the property (zero), how many open violations the building has with the city’s Department of Housing Preservation and Development (one, for a faulty lock), and a list of other buildings my landlord owns nearby.

That second site is Who Owns What, one of several digital tools created by tech nonprofit to empower the city’s renters. Enter the address of a New York City residential building into the Who Owns What search bar and you’ll get clear ownership information and other useful data points, more readily than you’d be able to pull that information from a city or state-run web portal.

Shielding identities behind LLCs is a common practice for landlords in cities across the country, including in New York City, where one building alone in south Williamsburg notoriously serves as the registered address and rent-check-pickup-point for hundreds of anonymous property owners. Having a tool that demystifies building ownership information can help renters take their landlords to court or organize with tenants in other buildings. It also helps policymakers and housing advocates connect the dots of problematic landlord behavior, spotting patterns of harassment and neglect, questionable eviction practices, or over-leveraged property owners across the city.

“Making those connections between buildings has historically been really difficult,” says Georges Clement, co-founder and executive director of “Most people will pay rent to 110th Street LLC, rather than the true owner of the building. We try to unmask those owners behind the LLCs and make connections to map out the true ownership portfolios across New York City.”

The algorithm that allows JustFix to do so draws registration data from the city Department of Housing Preservation and Development (HPD) in real time to search roughly 170,000 residential buildings for registered owner information. When the tool runs into an anonymous LLC, it gathers “head officer,” “individual owner,” or “corporate owner” contact information for that LLC (data that is also hosted by HPD), then searches through other HPD records for any additional properties associated with that owner.

The tool also pulls data about violations and complaints from HPD, job application filings from the Department of Buildings (DOB), tax lot data from the Department of City Planning, eviction data from the Association for Neighborhood and Housing Development and the Housing Data Coalition (supplied by New York City Marshals), tax exemption data from NYC Open Data, deed records from the Automated City Register Information System, and rent stabilization information from the city Department of Finance (via

For tenants, housing organizers, legal advocates, and reporters, the user-friendly simplicity of Who Owns What makes it a remarkable tool, and far more convenient than sifting through the aforementioned city records.

“We use Who Owns What and other JustFix tools every single day,” says Catherine Barreda, director of the Tenant Rights Coalition at Brooklyn Legal Services, a group that helps battle evictions, preserve affordable housing, and fight for safe living conditions for its clients. “We use Who Owns What any time we do an intake with a tenant to learn more about the building. For example, is it stabilized? How many units are there? Who is the owner, and is it a known bad player? Are there vacate orders in place? How many violations have been issued lately with HPD or DOB? Is there pending litigation by HPD in housing court against the landlord?”

According to Barreda, Brooklyn Legal Services also recommends the tool to tenants. “It is a game-changing tool that empowers often-marginalized tenants to fight for and get the safe and habitable homes they deserve.”

JustFix has created a suite of other useful tools for renters as well, leveraging open data, expert insight, and technological know-how to empower renters to send a hardship declaration during the eviction moratorium; send a certified letter of complaint to request repairs; or to check their apartments’ rent history, which is necessary to challenge a rent increase or illegal overcharge for a rent-stabilized unit.

Of course, these tools are location-specific, reliant on public data available in New York City. Could tech savvy groups outside of New York City replicate JustFix’s success, building similar products to address housing issues in their communities? Here’s how the tools in New York City came to be.

helping tenants build cases

JustFix got its start in 2015 through a tech incubator fellowship at Blue Ridge Labs, a program of Robin Hood, a major New York City-based philanthropic organization. The Labs program gave Clement and co-founders Dan Kass and Ashely Treni funding, space, and access to experts as they developed their initial tool, which helps renters build a case to present in housing court.

At the time, Clement and Treni spent weeks talking with tenants, housing court judges, and legal aid attorneys. They watched housing court proceedings around the city, taking careful note of what tenants needed, and where their pain points were.

As they watched renter after renter fumble with stacks of papers and struggle to put together a timeline of events and evidence to support their claims, helping tenants present a strong case in court emerged as an area of need. The resulting tool allows renters to assemble documentation, helps housing court judges get a clear picture of the situation, and helps case workers manage reams of information about many different tenants.

Similarly, to create the Who Owns What tool, the group learned the research strategies that tenant organizers, lawyers, and beleaguered renters had been relying on for years to uncover owner information on a case-by-case basis, then applied that process at scale, in the form of a handy search bar that scans—in real time—the 200,000-plus residential buildings across New York City.

Before the Who Owns What tool became available, tenants and their advocates would search for ownership information through Department of Finance tax records or property registration records kept by HPD. If they ran into an anonymous LLC listed as the building owner, they’d have to search for the LLC’s “head officer” or “individual owner” information separately—assuming they knew how to do so. There was no easy way to match an LLC owner’s name with all its associated properties.

By learning about this manual process from the people who relied on it, Clement and his team were able to create a user-friendly tool that automated the task.

“An absolutely necessary aspect of developing any of the services that we’ve built over the years is a high level of participation and partnership with tenants and their advocates,” Clement says.

JustFix has a design advisory council consisting of tenant leaders and representatives from community-based organizations across the city, like Chhaya Community Development Corporation, Community Action for Safe Apartments, IMPACCT Brooklyn, and several tenant associations.

This group helps keep the product team at JustFix apprised of issues that New York City renters are facing, so they can design relevant tools. For example, the design advisory council helped design and develop a referral directory of local tenant organizing groups, which can be requested and is sent to tenants for free after using any JustFix service. The council also keeps the technical team at JustFix plugged into local advocacy work, so they can build products and focus on data analysis that aligns with the goals of their partners.

The technical team—which now consists of two engineers and a UX designer (a third engineer and a UX researcher are starting shortly)—is engaged in creating new products, but also in testing existing products and updating them on an ongoing basis.

“We aren’t just building something and putting it on the internet. We’re building something and putting a lot of energy into actually getting it used, and then getting feedback from those users and continuing to iterate and improve over time. It’s a continuous process,” says Clement.

Now, more than five years after it began, JustFix is funded by grants from Robin Hood and organizations like Open Society Foundations, the Robert Wood Johnson Foundation, and the Chan Zuckerberg Initiative. They also receive a small portion of their funding from the discretionary budgets of local elected officials. The group’s total annual budget is around $1.5 million.

the data

In addition to technical talent and insight from community groups, JustFix runs on data.

Most of the data the startup uses to power its tools, like the property ownership information that underpins Who Owns What, or the rent history search tool, comes from the city’s open data portal, Clement says. But the availability of data varies significantly from place to place, and New York City is on the progressive side when it comes to publishing data for anyone to use, thanks to an Open Data Law signed by Mayor Michael Bloomberg in 2012. In other cities, “everyone runs into slightly different challenges,” Clement says. In Pittsburgh, for example, a similar project is attempting to crowdsource data because there is no available rent registry.

Still, there are several projects outside of New York City drawing inspiration from JustFix with publicly available data. JustFix convened a group called the Landlord Research and Mapping Coalition, a panel of “civic hackers” using public data to support housing justice in cities across the country and internationally. Coalition members in Los Angeles built “Own It,” a tool that identifies building owners and aggregates information about their portfolios, like how many other buildings are associated with the landlord and how many housing code violations the property has, using data from the LA County Assessor’s Office and Los Angeles County Department of Health. A group in Chicago built a similar tool called Find My Landlord. Other members of the coalition are working on mapping evictions, and identifying stakeholders affected by private-equity investments.

What data they can access, what they can do with it, and how they can get access to more is a frequent topic of conversation among the coalition’s members, Clement says.

But some of the useful resources JustFix provides don’t require much data at all and are likely doable anywhere. The tool that helps tenants build a letter of complaint requesting repairs from their landlord, for example, is informed by local housing attorneys, but doesn’t rely on other data points from the city, only a digital letter-building template and a function to send the letter for free by certified mail. JustFix partnered with Strategic Actions for a Just Economy in Los Angeles to create a similar letter-building tool for tenants declaring an inability to pay rent during the eviction moratorium.

getting tools to tenants

While developing tools for housing justice is a positive thing, what makes the tools truly helpful is making sure they’re accessible to tenants. To help with language accessibility, JustFix’s services are available in English and Spanish.

The text-bot rent history tool is a step toward bridging the digital divide, helping renters without internet access find their apartment’s rent history. Users in rent stabilized buildings can text “RENT HISTORY” to 855-610-2450, follow a series of prompts, and then receive their apartment’s rent history in the mail from the state Division of Housing and Community Renewal, no internet or computer access required.

One of JustFix’s tools suddenly became inaccessible after a decision from the New York City Housing Court. It had allowed renters to file a lawsuit against their landlords for free through the court’s e-filing system typically used only by attorneys. It launched in April 2020 and was used by some 3,000 tenants before it was blocked by the court in June 2021. The court had initially supported the tool and worked with JustFix to create it, before the decision requiring all complaints be filed in person, with notarized papers and a $45 fee.

This disappointing experience may offer some lessons for other groups, Clement says. “I would be more cautious of building tools that require the collaboration of government institutions and systems in helping tenants to take action. If you’re supporting people accessing a particular institution, people are still at the whims of that institution.”

Overall, he urges anyone inspired by JustFix to work closely with tenants, community-based organizations, and legal aid providers, and to plan to spend a lot of effort on distribution and awareness-raising once the products are created.

“Designing and developing great services is important, but it’s not that important if nobody uses them,” Clement says. “There needs to be a lot of time and energy spent actually making sure the people who most need the services are aware of and able to access them.”

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