NYC property research guide
NYC building permit history: how to trace work on a building
A building's permit history lives in two DOB systems and several datasets. Put the records in date order, keep each system's status as published, and note what is missing.
Identify the building, then the lot
DOB organizes most records by building identification number (BIN) and job number, and links them to a tax lot by BBL or by borough, block, and lot. Resolve the address to both before searching, because a lot can hold several buildings and a building's address can change.
When an address returns nothing, search by BIN or by borough, block, and lot. Address spellings in DOB data are not normalized.
Two systems, one history
DOB NOW is the current filing system. Filing types moved into it in phases, so recent work is usually in DOB NOW: Build, while older jobs, and some job types filed before their migration, remain in the Building Information System (BIS).
Search both. The DOB NOW job filings and approved permits datasets on NYC Open Data cover DOB NOW, and DOB's Permit Issuance dataset and BIS cover legacy jobs. A history drawn from only one system is incomplete.
- List each job with its job number, filing date, work type, and current status.
- List each permit with its issue and expiration dates and the job it belongs to.
- Keep sign-off and certificate-of-occupancy records separate from permits.
Read dates and statuses literally
A filing date is when an application was submitted, not when work began. An issue date is when a permit was granted, and an expiration date is when it lapsed unless renewed. A status reflects the system's value at the time it was published and can change after you look.
Descriptions are written by applicants and can be brief or amended. When scope matters, open the official job and permit record and read the plans and approvals.
Where the public record stops
A permit does not prove that work was completed, inspected, or signed off. The absence of a permit does not prove that no work happened or that none was required. Some older records were never digitized and exist only in DOB's archive.
LotContext collects DOB NOW job filings and approved permits for a lot and orders them by date, with the source and retrieval time for each. It does not yet include BIS jobs or certificates of occupancy, so check BIS directly for older work.
Official sources
Open the publisher's current record and documentation before relying on a material item.
- DOB NOW: Build – Job Application Filings Official source · checked October 15, 2026
- DOB NOW: Build – Approved Permits Official source · checked October 15, 2026
- DOB Permit Issuance (legacy BIS) Official source · checked October 15, 2026
- DOB Building Information Search (BIS) Official source · checked October 15, 2026
- DOB NOW public portal Official source · checked October 15, 2026
Related NYC property research guides
DOB NOW vs. BIS: where to search NYC building records
A practical comparison of DOB NOW and BIS, including which NYC permits, filings, violations, complaints, and occupancy records each system contains.
Read guide →How to research NYC DOB permits and job filings
A guide to DOB NOW and legacy BIS permit data, job filings, dates, identifiers, and common interpretation mistakes.
Read guide →How to find and read an NYC Certificate of Occupancy
Where to find NYC Certificates of Occupancy in DOB NOW and BIS, what floor-use records show, and what a missing or temporary certificate means.
Read guide →Research the property with source status intact
LotContext organizes supported NYC public records into a private evidence workspace. Current free limits are 3 queries per rolling 24 hours and 20 per rolling 30 days.