| Primary address | 21 Duncan Avenue, Ronkonkoma |
| Zip code | 11779 |
| County | Suffolk |
| Municipality | Brookhaven |
| Parcel ID | 6238166 |
View detailed information on past sales, title documents and property taxes, including the assessed market value, in their dedicated tabs.
| Sale date | 12/27/2007 |
| Sale price | $368,000 |
| Arm's length | Register |
| Property tax | $11,125 |
| Building sqft | 2,023 |
| Building class | One Family Year-Round Residence (210) |
| Acreage | 0.21 |
| Year built | 1978 |
| Rooms | 7 |
| Bedrooms | 3 |
| Bathrooms | 1 |
| School district | Sachem |
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:
21 Duncan Avenue, Ronkonkoma, NY 11779 was built in 1978 and has a total of 2,023 square feet.
What is the assessed value of 21 Duncan Avenue, Ronkonkoma, NY 11779 and the property tax paid?Assessed at $3,150, the tax amount paid for 21 Duncan Avenue, Ronkonkoma, NY 11779 is $11,125.
When was 21 Duncan Avenue, Ronkonkoma, NY 11779 last sold and what was the last sale price?21 Duncan Avenue, Ronkonkoma, NY 11779 was last sold in 12/27/2007 for $368,000.
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 21 Duncan Avenue, Ronkonkoma, including title documents, transfer conditions, mortgages and liens.
*Here are the three most recent sales for this property.
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 21 Duncan Avenue, Ronkonkoma, NY 11779. Tax information included: property tax, market value and assessed value, exemptions, abatements, and assessment history.
| Tax year | 2025-2026 |
| Property tax | $11,125 |
| Market value | $594,339 |
| Assessed value | $3,150 |
Here's the assessment & property tax history for 21 Duncan Avenue, Ronkonkoma, 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 |
|---|---|---|---|---|---|
| 2024-2025 | $594,339 | $3,150 | 338.342 | $10,658 | -17.92% |
| 2023-2024 | $583,333 | $3,150 | 412.188 | $12,984 | +27.16% |
| 2022-2023 | $508,064 | $3,150 | 324.157 | $10,211 | +3.72% |
| 2021-2022 | $425,675 | $3,150 | 312.54 | $9,845 | +2.63% |
| 2020-2021 | $409,091 | $3,150 | 304.524 | $9,593 | +1.29% |
The complete history of permits filed for 21 Duncan Avenue, Ronkonkoma, 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 21 Duncan Avenue, Ronkonkoma, 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 21 Duncan Avenue, Ronkonkoma 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) |
|---|---|---|---|---|---|
| Hiawatha School | 4 | Public | K-5 | 603 | 0.50 |
| Nokomis School | 3 | Public | K-5 | 527 | 1.05 |
| Maimonides Day School | NR | Private | PK, K-3 | 25 | 1.10 |
| Maimonides Day School | NR | Private | PK, K-3 | 25 | 1.10 |
| St Joseph School | NR | Private | PK, K-8 | 212 | 1.13 |
| Name | Rating | Type | Grade range | No of students | Distance to school (mi) |
|---|---|---|---|---|---|
| Samoset Middle School | 6 | Public | 6-8 | 892 | 0.51 |
| St Joseph School | NR | Private | PK, K-8 | 212 | 1.13 |
| Lake Grove School | NR | Private | 8-12 | 50 | 2.01 |
| Cleary School For The Deaf | NR | Private | PK-12 | 79 | 2.11 |
| Seneca Middle School | 6 | Public | 6-8 | 973 | 2.12 |
| Name | Rating | Type | Grade range | No of students | Distance to school (mi) |
|---|---|---|---|---|---|
| Sachem High School North | 8 | Public | 9-12 | 1,923 | 0.87 |
| Lake Grove School | NR | Private | 8-12 | 50 | 2.01 |
| Cleary School For The Deaf | NR | Private | PK-12 | 79 | 2.11 |
| Our Savior New American School | NR | Private | PK, K-12 | 122 | 2.72 |
| Long Island Baptist Academy | NR | Private | 2-12 | 8 | 2.80 |
Data provided by GreatSchools.org © 2025. All rights reserved.
Here are the neighbors for 21 Duncan Avenue, Ronkonkoma.
| Address | Square feet | Purchase date | Purchase price |
|---|---|---|---|
| 14 Acorn St, Ronkonkoma | 1,421 | 11/15/2013 | |
| 16 Acorn St, Ronkonkoma | 624 | 09/04/2021 | |
| 37 Duncan Ave, Ronkonkoma | 1,914 | ||
| 36 Creighton Ave, Ronkonkoma | 1,648 | 02/07/2022 | $550,000 |
| 21 Creighton Ave, Ronkonkoma | 770 | ||
| 27 Duncan Ave, Ronkonkoma | 507 | 04/25/2022 | $275,000 |
| 15 Oak St, Ronkonkoma | 1,639 | 04/18/2023 | $551,050 |
| 22 Patchogue Rd, Ronkonkoma | 12/03/2013 | $221,540 | |
| 29 Creighton Ave, Ronkonkoma | 756 | 08/18/2020 | $322,000 |
| 31 Duncan Ave, Ronkonkoma | 1,060 | 04/11/2025 | $565,000 |
| 30 Creighton Ave, Ronkonkoma | 1,008 | ||
| 28 Creighton Ave, Ronkonkoma | 1,772 | ||
| 12 Acorn St, Ronkonkoma | 1,876 | 10/31/2007 | |
| 32 Patchogue Rd, Ronkonkoma | 08/08/2025 | $585,000 | |
| 23 Creighton Ave, Ronkonkoma | 1,600 | ||
| 20 Creighton Ave, Ronkonkoma | 1,472 | 07/20/2009 | |
| 27 Creighton Ave, Ronkonkoma | 674 | 04/23/2007 | |
| 39 Duncan Ave, Ronkonkoma | 2,067 | 04/17/2014 | $290,000 |
| 24 Creighton Ave, Ronkonkoma | 480 | 03/08/2018 | $150,013 |
| 28 Patchogue Holbrook Rd, Ronkonkoma | 1,326 | 11/08/2010 |