409 Sackett Street, Brooklyn

An 1899 Carroll Gardens single-family home with a recent $8.15M flip and high curb activity on the surrounding blocks.

A single-family Carroll Gardens townhouse built in 1899 that traded hands twice recently after nearly five decades in one family. Because it operates as a single residency, there is no shared-hall tenant friction on file. Three things to know:

A steep valuation jump indicates a massive recent renovation. The property transferred for $3.25M in late 2022 to an LLC, then re-sold in December 2025 for $8.15M to private buyers. A price jump of that size points to substantial structural and interior renovation work undertaken between transfers.

Air quality and restaurant venting calls pop up nearby. Within three blocks, neighbors logged 6 food establishment complaints and 5 indoor air quality calls over the last year. Ground-level odors and commercial exhaust drift are unpredictable until you stand inside the space.

Curb friction and street noise cluster on the surrounding blocks. The surrounding area logged 352 illegal parking complaints in the last 12 months, driven primarily by 90 blocked hydrants and 87 commercial overnight parking reports. Street noise added 95 calls, mostly loud parties.

Quieter signals on this building and the blocks around it:

• The building carries 7 open administrative code violations for missing annual filings.
• The area recorded 49 helicopter noise reports over the last 12 months, last seen in May 2026.

409 Sackett Street is a single-family home in Brooklyn, New York City (BBL 3004220048). This building is associated with Grennan, Mark. Brix tracks 7 open HPD violations for this property, along with inspection history, DOB filings, tenant complaints, and rent stabilization status.

Built in 1899, this single-family home sits in Brooklyn and is tracked by Brix using public NYC records from HPD, DOB, ACRIS, and 311.

Conditions cited on open violations at this address:

• (A) § HMC:FILE ANNUAL BEDBUG REPORT IN ACCORDANCE WITH HPD RULE AS DESCRIBED ON THE BACK OF THIS NOTICE OF VIOLATION OR AS DESCRIBED ON HPDS WEBSITE, WWW
• §27-2107 ADM CODE OWNER FAILED TO FILE A VALID REGISTRATION STATEMENT WITH THE DEPARTMENT AS REQUIRED BY ADM CODE §27-2097 AND IS THEREFORE SUBJECT TO CIVIL PEN

The building last changed hands on February 17, 2026 for $4,000,000, according to recorded deeds.

Brix score: 40/100. View the Building Report on Brix.

See every NYC building owned by Grennan, Mark on the landlord portfolio page.