21 William Ave, Glen Head, NY 11545 Property Records

Nassau County and Oyster Bay Town property record for 21 William Ave, Glen Head, NY 11545

Property Summary

Property Type	Single Family Home
Details	3 ba · 2,019 sqft · built 1954
Lot Size	0.206 acres (8,960 sqft)
Owner	2 Individual Names on Record
Last Sale	$690,000 (Dec 2020)
Tax Bill	$2,650 (2025)
Deeds & Mortgages	Dec 2020 Sale & Mortgage
Flood Zone	Zone X (minimal risk)
APN	`21-227-00-0016`

Property Details

APN / Parcel Number

Primary APN	`21-227-00-0016`
Alternative APNs	`2489-21-227-00-0016-0` `21227000016000000000` `282489 21.-227-16` `21227 00160`

Interior

Full Baths	3 Baths
Total Rooms	9 Rooms
Stories	1 Story
Building Area	2,019 sqft Living Area
Gross Area	2,713 sqft
1st Floor Area	1,150 sqft
Basement Area	264 sqft
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1954
Effective Year Built	Effective 1954
Architectural Style	Cape Cod
Exterior Material	Wood
Construction Type	Frame
Roof Material	Other
Lot Area	8,960 sqft (0.206 acres)
Lot Dimensions	100 ft deep x 90 ft wide
Garage Type	Attached
Garage Area	322 sqft
Parking Spaces	1 Parking Space

Exterior Amenities

Porch	Enclosed Frame Porch
Porch Area	133 sqft
Deck Area	295 sqft
Patio Area	295 sqft

Utilities, Heating & Cooling

Cooling System	Central
Heating System	Central
Heating Fuel	Oil
Sewer	Municipal
Water Source	Commercial

Location & Zoning

Account Number	21227 00160
Street Address	21 WILLIAM AVE
City	GLEN HEAD
State	NY
Zip	11545-1427
Property Category	Residential
Property Type	Residential > Single Family > Home
Legal Description	TOWN #3 SCH DIST 001
Legal Block	227
Legal Lot Number	16
Jurisdiction	NASSAU NY
Township / Civil Division	OYSTER BAY
Census Block Group	4
Census Block	4000
Census Tract	517600

Owner

Source: Nassau County and Oyster Bay Town records, as of June 17, 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record	2 Individual Names on Record
Mailing Address	21 WILLIAM AVE, GLEN HEAD, NY 11545-1427
Occupancy	Owner Occupied
Owner Type	Individual

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	2 Names on Deed
Last Sale	Dec 16, 2020 · Amount on Record
Deed Sale	Dec 16, 2020 · Amount on Record
Deed Document Number	2020123053
Deed Book / Page	14014 / 137
Prior Transfer Date	Nov 24, 2015
Prior Transfer Doc	0133260035
Record Updated	Sep 20, 2026

December 2020: Executor's Deed, Transfer

Document Type	Executor's Deed
Jurisdiction	NASSAU NY
Recording Date	Dec 16, 2020
Property Address	21 WILLIAM AVE, GLEN HEAD, NY 11545-1427
Document Number	0140140137
Book / Page	14014 / 137
Map Reference	MAP 5716
Instrument Date	Nov 25, 2020
Instrument	2020-123053
Transaction Type	Transfer
Record Updated	May 14, 2021
Title Company	FIRST AMERICAN TITLE

Transaction

Amount	Amount Recorded
Downpayment	Downpayment on Record
Loan-to-Value (LTV)	LTV on Record
Tax	$2,760.00
Amount Accuracy	Rounded by County
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name
Address	8 PRINCESS GATE, 8, STONY BROOK, NY 11790-1838

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	373 E 74TH ST, NEW YORK, NY 10021-3701

Mortgage

Document Number	202012305444827313
Date	Dec 16, 2020
Instrument	2020-12305444827313

Lender

Name	LYONS MORTGAGE SERVICES INC

Agreement

Type	Conventional Mortgage
Amount	Amount Recorded

Tax Assessment & Valuation

Source: Nassau County and Oyster Bay Town assessment roll, as of June 17, 2026

Property Jurisdictions

Type	Name
State	New York
County	Nassau County
County Subdivision	Oyster Bay Town
Unified School District	North Shore Central School District (KG - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2026		$670 (-3.32%) Land $242 Building $428	$670,000 (-3.32%)
2025	$2,650.00 (-5.93%) Additional exemption filed	$693 (-4.94%) Land $250 Building $443	$693,000 (-4.94%)
2023	$2,817.00 Additional exemption filed	$729 Land $263 Building $466	$729,000

Assessed value and assessed market value are set for property tax purposes, not market price estimates; both are a fraction of this property's market value.

Flood

Source: FEMA National Flood Hazard Layer, effective April 5, 2023 · OpenFEMA NFIP redacted claims and policies, as of September 2026

FEMA Flood Zone	Zone X minimal risk
Flood Insurance Requirement	Not required lenders may require it
Nearby Flood Policies	5 in force
Nearby Flood Claims	5 (1978–2021)
Claims Outside the SFHA	1 of 5
Most Recent Claim	Sep 2021 · Remnants Of Hurricane Ida

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Wildfire

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire Risk	Low lower than 80% of the US · above 54% of New York
Wildfire Likelihood	0.01% annual chance
Exposure	None beyond ember reach

Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water System	LIBERTY UTILITIES NEW YORK - SEA CLIFF private · serves 13,400 people · EPA ID NY2902853
Water Source	Groundwater
Last State Inspection	Jan 2024
Lead	Under 1 ppb (2021–2023) action level 15 ppb

Violations Reported to EPA

Water Quality	None last 10 years
Treatment and Procedure	None last 10 years
Monitoring and Reporting	None last 3 years

Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.

Internet Providers

Source: FCC Broadband Data Collection, based on 546 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
Optimum Fiber · Cable	8,000 / 8,000
Verizon Fiber	2,300 / 2,300
T-Mobile Fixed Wireless	100 / 20