Location and Projects
KOSL Building Photos
KOSL Building Construction
KOSL Building has been developing high-end homes throughout Westchester County, NY and Greenwich, CT for over 35 years. Focusing on premium locations and quality craftsmanship, KOSL facilitates a seamless new construction package from start to finish. Our turnkey services involve property acquisitions, designing plans, land-use approvals, financing solutions and construction management, resulting in a streamlined process. Renowned for our extensive expertise and exceptional service, KOSL has been distinguished through various awards as the top residential builder in Westchester, NY for several years without plateau. Having developed over 200 high-quality homes, our experience and customer service has continued to flourish permitting us to accommodate any client’s needs. Contact us today to get started on your dream home!
From BuildZoom: KOSL Building, 875 Mamaroneck Ave, Mamaroneck, NY (Employees: Bobby Ben Simon and Oran Ben Simon) holds a Home Improvement Contractor license and 3 other licenses according to the Westchester County license board.
Their BuildZoom score of 104 ranks in the top 9% of 77,888 New York licensed contractors.
Their license was verified as active when we last checked. If you are thinking of hiring KOSL Building, we recommend double-checking their license status with the license board and using our bidding system to get competitive quotes.
KOSL Building Services
KOSL Building Contact Information
This is a sample of this contractor's permits. Click here to access their complete permit history.
KOSL Building Reviews
Hiring a contractor?
KOSL Building License info
Verified License
| Status | Active |
| County | Westchester County |
| Type | Home Improvement Contractor |
| Business Type | Limited Liability Company (Llc) |
- BuildZoom verified this license was active as of July 2026.
This is a sample of licensing data; click here to access a complete history.
Verified License
| License # | NHC.0009386 |
| Status | Active |
| State | Connecticut |
| Type | New Home Contractor |
| Date Issued | 04-01-2026 |
| Business Type | Limited Liability Company (Llc) |
- BuildZoom verified this license was active as of July 2026.
Verify this license's status for KOSL Building at the Connecticut Department of Consumer Protection.
This is a sample of licensing data; click here to access a complete history.
License Not Verified
| License # | WC31326H18 |
| Status | Active |
| County | Westchester County |
| Type | Home Improvement License |
| Business Type | Limited Liability Company (Llc) |
- When BuildZoom last verified this license, it had an expiration date of December, 2024. Check the current license status of KOSL Building with the Consumer Westchester County, NY
This is a sample of licensing data; click here to access a complete history.
Inactive License
| Status | Inactive |
| County | Westchester County |
| Type | Home Improvement Contractor |
| Business Type | Limited Liability Company (Llc) |
- According to the Consumer Westchester County, NY, the status of this license was at one point cancelled. However, this information may have changed.
This is a sample of licensing data; click here to access a complete history.