Why the NYC Buildings Information System Remains Essential for Property Research

The Buildings Information System (BIS) serves as the primary legacy database for the New York City Department of Buildings (DOB). Despite the city's aggressive transition toward the modern DOB NOW platform, BIS continues to hold billions of data points regarding property profiles, historical construction filings, and enforcement records for over one million buildings across the five boroughs. For property owners, real estate professionals, and contractors, navigating BIS is not just a technical requirement but a necessity for ensuring legal compliance and performing thorough due diligence.

Understanding the Role of BIS in the Modern Era

The New York City Department of Buildings regulates the safe and lawful use of more than 1,000,000 buildings and 44,400 active construction sites. While the newer DOB NOW portal handles most new permit filings and modern compliance reports, BIS remains the centralized repository for historical data.

Currently, the city is in a dual-system phase. As of the 2025 fiscal reporting period, job filings in BIS have decreased significantly—representing less than 5% of total volume—yet the system remains the only place to access records that predate the 2016-2020 migration period. If a researcher needs to find an original Certificate of Occupancy from the 1950s or check the status of a violation issued in the 1990s, BIS is the only source of truth.

Navigating the Property Profile Overview

The entry point for most users is the Property Profile Overview. By entering a specific address, borough, block, and lot (BBL), or Building Identification Number (BIN), users gain access to a dashboard that summarizes the entire legal history of a structure.

Key Identifiers: BIN and BBL

Every building in New York City is assigned a unique seven-digit Building Identification Number (BIN). This is often more accurate than a street address, which can vary if a building sits on a corner or has multiple entrances. The Block and Lot (BBL) system connects the DOB data to the Department of Finance records, allowing users to verify tax information and ownership alongside building safety records.

Special Zoning and Landmarks

The Property Profile highlights critical zoning designations. Users can immediately see if a property is located within a "Little Italy Special District" or a "Coastal Zone Management" area. Furthermore, it indicates if a building is under the jurisdiction of the Landmarks Preservation Commission (LPC). This information is vital for any planned renovation, as landmarked buildings require additional layers of approval before even minor aesthetic changes can be made.

Decoding Violations and Enforcement Data

One of the most frequent uses of BIS is checking for open violations. The system tracks three distinct categories of enforcement actions, each with different resolution requirements.

Environmental Control Board (ECB) Violations

ECB violations, now often referred to as OATH violations, are the most serious because they usually carry significant financial penalties. In BIS, these are listed in either "Active" (A) or "Dismissed" (D) status. It is a common misconception that paying the fine closes the violation. In reality, an ECB violation remains "Active" in BIS until a Certificate of Correction is submitted to and approved by the DOB’s Administrative Enforcement Unit.

DOB Violations

These are internal department violations that may not carry an immediate fine but can prevent a property from obtaining a new Certificate of Occupancy or closing a sale. In BIS, dismissed DOB violations are marked with an asterisk (e.g., V*705218P), while open ones appear without the asterisk. These often relate to missing annual inspections for boilers or elevators.

Electrical and Equipment Violations

Specialized units within the DOB issue violations for faulty wiring or unsafe machinery. BIS allows users to track the status of elevator inspections and boiler filings. For property managers, keeping these systems in "Closed" status is essential for passing annual safety audits and avoiding the city's proactive enforcement teams.

The Significance of the Certificate of Occupancy (C of O)

The Certificate of Occupancy is the most important legal document for any building. It describes how a building may be occupied (e.g., a two-family residential home vs. a commercial storefront) and ensures that the structure complies with all building codes and zoning laws.

In the BIS portal, users can view and download scanned copies of historical C of Os. If a building was constructed before 1938 and has not undergone significant structural changes, it may not have a C of O. In these cases, BIS will often show a "Letter of No Objection" or other alternative documentation. Researching this in BIS is a standard part of the "due diligence" process for any real estate transaction in New York, as a missing or incorrect C of O can lead to the denial of a mortgage or insurance policy.

Jobs and Permits: From NB to Alt-3

BIS categorizes construction activity into several "Job Types." Understanding these codes is essential for anyone trying to interpret the construction history of a property:

• NB (New Building): Full construction of a new structure.
• Alt-1 (Alteration Type 1): Major alterations that change the use, egress, or occupancy of a building. These require a new or amended Certificate of Occupancy.
• Alt-2 (Alteration Type 2): Multiple work types (plumbing, mechanical, etc.) that do not change the occupancy.
• Alt-3 (Alteration Type 3): Minor work involving a single work type, such as erecting a temporary fence or a small curb cut.

While new Alt-1 and NB filings have moved to DOB NOW, many ongoing projects initiated before the transition are still managed through BIS. The system provides a chronological list of every application, the names of the Registered Architects (RA) or Professional Engineers (PE) involved, and the status of the "Job Start" and "Sign-off."

Comparing BIS and DOB NOW

The transition from the legacy BIS to the modern DOB NOW platform has created a bifurcated research process. Users must understand which system to use to avoid missing critical information.

For example, if a property owner is looking for a permit issued in 2024 for a new boiler, they must look in DOB NOW: Build. However, if they are looking for the original 1985 plumbing plans for that same building, they must search BIS.

How to Conduct Effective Property Research in BIS

To maximize the value of a BIS search, follow these strategic steps:

1. Check the Property Profile Overview first. Look for "Open" violations or "Unsafe" façade conditions. An unsafe façade (Local Law 11) will often result in a building being surrounded by sidewalk sheds, a key focus of the city’s current "Get Sheds Down" initiative.
2. Examine the "Items Required" list. For ongoing jobs, BIS lists what the DOB still needs to sign off on a project. This could include final plumbing tests or electrical inspections.
3. Review the Complaint History. BIS stores records of 311 calls and public complaints. A high volume of recent complaints regarding "Illegal Conversion" or "Work Without a Permit" is a red flag for potential buyers.
4. Verify Licenses. BIS includes a search function for skilled trades. You can verify if a plumber, electrician, or high-pressure boiler operating engineer holds a valid, active license before hiring them.

The Impact of Local Law Compliance

New York City’s sustainability and safety goals are increasingly reflected in BIS data. Local Law 97 (carbon emissions) and Local Law 11 (façade safety) results are tracked within these systems. The DOB uses predictive analytics and historical data from BIS to target "negligent owners" and "bad actors" in the industry. For owners, this means that a history of unresolved violations in BIS makes the property a higher priority for proactive inspections, potentially leading to more frequent visits from the DOB enforcement teams.

The Future of BIS Data

While BIS is a "legacy" system, it is not being deleted. The data is slowly being integrated into the city’s Open Data portal and modern interfaces. However, the raw, granular detail of the original filings remains unique to the BIS search portal. The Department of Buildings continues to maintain this infrastructure to support the legal framework of New York real estate, ensuring that every permit ever issued remains a matter of public record.

Summary

The NYC Buildings Information System (BIS) remains the cornerstone of property data in New York City. While DOB NOW is the future of filing, BIS is the definitive record of the past. From identifying historical violations to verifying a property’s legal occupancy, the system provides a level of transparency that is essential for maintaining the safety and integrity of the city’s built environment. Mastering this tool allows stakeholders to navigate the complexities of NYC construction codes with confidence.

Frequently Asked Questions

What should I do if I find an open violation in BIS that was paid years ago?

Paying a fine at the ECB/OATH tribunal does not automatically close a violation in the BIS system. To "Close" the violation in BIS, you must submit a Certificate of Correction (Form AEU-2) to the DOB Administrative Enforcement Unit, proving that the illegal condition has been fixed.

Why can't I find a permit issued in 2023 in the BIS system?

Since 2021, almost all new job filings (including New Buildings and major alterations) have moved to the DOB NOW: Build portal. If a permit is not in BIS, it is likely located in the DOB NOW system.

Can I see building plans and blueprints on BIS?

For security reasons, full architectural blueprints are not available for public download on BIS. You can see the summaries, job descriptions, and approvals, but to view actual plans, you must visit the specific DOB Borough Office and provide proof of ownership or authorization.

What does it mean if my building has a "V* " mark in BIS?

A violation number followed by an asterisk (e.g., V*123456) indicates that the DOB violation has been dismissed or resolved. If there is no asterisk, the violation is considered open and active.

How do I find the BIN (Building Identification Number) for a property?

When you search for a property by address on the BIS homepage, the BIN will be displayed at the top of the Property Profile Overview page. It is a seven-digit number beginning with a 1, 2, 3, 4, or 5 depending on the borough.