| Primary address | 20 Williams Avenue, Syosset |
| Zip code | 11791 |
| County | Nassau |
| Town/City | Oyster Bay |
| Village (swiss code) | None (unincorporated town) |
| Parcel ID | 15-80-28 |
View detailed information on past sales, title documents and property taxes, including the assessed market value, in their dedicated tabs.
| Tax class | Register |
| Current property tax | $11,829 |
| Building sqft | 1,071 |
| Building class | One Family Year - Round Residence (210.01) |
| Land | Primary site |
| Topography | Level |
| Acreage | 0.226 |
| Buildings on lot | 1 |
| Year built | 1955 |
| Stories | 1 |
| Style | Ranch |
| Rooms | 6 |
| Bathrooms | 1 |
| Attic | None |
| Basement | Full |
| Exterior wall | Frame |
| Heating type | Central |
| Heating system | Hot water |
| Zoning district | Register (See more on map) |
| School district | Locust Grove |
View more neighborhood information such as transportation, nearby schools and risk designations in the dedicated tab.
Property reports include comprehensive occupancy, improvement and development information (where available).
Create a free account to access valuable data points such as:
20 Williams Avenue, Syosset, NY 11791 was built in 1955 and has a total of 1,071 square feet.
What is the assessed value of 20 Williams Avenue, Syosset, NY 11791 and the property tax paid?Assessed at $534, the tax amount paid for 20 Williams Avenue, Syosset, NY 11791 is $15,626.
When was 20 Williams Avenue, Syosset, NY 11791 last sold?20 Williams Avenue, Syosset, NY 11791 was last sold in 01/13/2012.
View detailed property contacts like owners, building management, representatives from permits and tenants with a free account.
Create a free account to view the complete sales history for 20 Williams Avenue, Syosset, including title documents, transfer conditions, mortgages and liens.
To view the complete history of deeds, mortgages, assignments of leases and rents, and more, sign up for free. Available data goes back to 1966.
R: Recorded date
D: Document date
Access detailed property tax data for 20 Williams Avenue, Syosset, NY 11791. Tax information included: property tax, market value and assessed value, exemptions, abatements, and assessment history.
| Tax year | 2026 |
| Base tax | $15,627 |
| Current property tax | $11,829 |
| Tax class | Register |
| Market value | $534,000 |
| Assessed value | $534 |
Here's the assessment & property tax history for 20 Williams Avenue, Syosset, including the evolution of the total tax rate and corresponding property tax.
| Year | Market value | Assessment value | Total tax rate | Property tax | Year over year change |
|---|---|---|---|---|---|
| 2025 | $534,000 | $534 | 2812.908 | $15,021 | -16.32% |
| 2024 | $534,234 | $534 | 3361.673 | $17,951 | +8.18% |
| 2023 | $534,000 | $534 | 3107.604 | $16,595 | -7.74% |
| 2022 | $534,000 | $534 | 3368.443 | $17,987 | -7.45% |
| 2021 | $520,000 | $520 | 3737.468 | $19,435 | +36.34% |
The complete history of permits filed for 20 Williams Avenue, Syosset, including new construction or demolition permits, plus any work pertaining to plumbing, heating and sprinkler systems is available with a free account. Available data goes back to 1990.
Create a free account to unlock extended information for 20 Williams Avenue, Syosset, including whether it's located in FEMA flood zones, floodways or special flood hazard areas, as well as the Coastal barriers resources system area (COBRA).
| FEMA flood zone(s) | X (See more on map) |
Access the detailed traffic volume map for 20 Williams Avenue, Syosset to see estimated average daily traffic on streets surrounding the property as well as the types of properties in its vicinity.
| View daily traffic map |
| Name | Rating | Type | Grade range | No of students | Distance to school (mi) |
|---|---|---|---|---|---|
| Willits Elementary School | 9 | Public | K-5 | 305 | 0.36 |
| South Grove Elementary School | 9 | Public | K-5 | 416 | 0.37 |
| Baylis Elementary School | 9 | Public | K-5 | 405 | 0.87 |
| St Edward Confessor School | NR | Private | PK-8 | 265 | 1.05 |
| St Edward Confessor School | NR | Private | PK-8 | 265 | 1.05 |
| Name | Rating | Type | Grade range | No of students | Distance to school (mi) |
|---|---|---|---|---|---|
| H B Thompson Middle School | 9 | Public | 6-8 | 997 | 0.50 |
| St Edward Confessor School | NR | Private | PK-8 | 265 | 1.05 |
| Fusion Academy Woodbury Ny | NR | Private | 6-12 | 75 | 1.08 |
| P.S. 256 | NR | Public | PK, K-12 | 500 | 1.46 |
| Plainview Old Bethpage Middle School | 8 | Public | 5-8 | 889 | 1.93 |
| Name | Rating | Type | Grade range | No of students | Distance to school (mi) |
|---|---|---|---|---|---|
| Fusion Academy Woodbury Ny | NR | Private | 6-12 | 75 | 1.08 |
| P.S. 256 | NR | Public | PK, K-12 | 500 | 1.46 |
| Our Lady Of Mercy Academy | NR | Private | 9-12 | 359 | 1.64 |
| Syosset Senior High School | 10 | Public | 9-12 | 2,266 | 2.03 |
| Good Shepherd Lutheran School | NR | Private | 0 | 2.09 |
Data provided by GreatSchools.org © 2025. All rights reserved.
Here are the neighbors for 20 Williams Avenue, Syosset.
| Address | Square feet | Purchase date | Purchase price |
|---|---|---|---|
| 27 Underhill Ave, Syosset | 1,997 | 10/16/2023 | |
| 14 Willets Ave, Syosset | 1,631 | 02/29/2000 | |
| 6 Williams Ave, Syosset | 2,802 | 03/07/2022 | $1,280,000 |
| 6 Willets Ave, Syosset | 1,810 | 10/17/2008 | $577,800 |
| 14 Williams Ave, Syosset | 1,351 | 12/05/2023 | $820,000 |
| 31 Underhill Ave, Syosset | 1,588 | 09/05/2024 | $799,000 |
| 18 Williams Ave, Syosset | 1,411 | 07/25/2018 | $625,000 |
| 12 Williams Ave, Syosset | 1,071 | 08/05/2009 | $425,000 |
| 4 Willams Ave, Syosset | 2,373 | 11/15/2021 | $1,150,000 |
| 32 A Underhill Ave, Syosset | 1,917 | 06/25/1996 | $267,000 |
| 8 Willets Ave, Syosset | 1,967 | 06/23/2009 | $475,000 |
| 10 Willets Ave, Syosset | 1,810 | 07/29/2014 | $560,000 |
| 22 Williams Ave, Syosset | 1,251 | 05/26/2015 | $600,000 |
| 32 Underhill Ave, Syosset | 1,925 | 07/10/2006 | $500,000 |
| 29 Underhill Ave, Syosset | 1,937 | 11/06/2025 | $1,238,888 |
| 12 Willets Ave, Syosset | 1,225 | 06/18/2025 | |
| 16 Williams Ave, Syosset | 1,071 | 02/10/2020 | |
| 10 Williams Ave, Syosset | 1,384 | 09/10/2012 | $450,000 |
| 8 Williams Ave, Syosset | 1,071 | 01/29/2010 | |
| 1 Hicks Ln, Syosset | 2,684 | 11/10/2005 | $820,000 |