512 S William St, Mount Prospect, IL 60056 Property Records

Cook County property record for 512 S William St, Mount Prospect, IL 60056

Property Summary

Property Type	Single Family Home
Details	3 bd · 1.5 ba · 1,254 sqft · built 1958
Lot Size	0.194 acres (8,448 sqft)
Owner	Individual Name on Record
Last Sale	$377,500 (Jul 2007)
Tax Bill	$7,693 (2023)
Deeds & Mortgages	Sep 2021 Mortgage Feb 2019 Mortgage + 1 more
Flood Zone	Zone X (minimal risk)
APN	`08-12-421-015`

Property Details

APN / Parcel Number

Primary APN	`08-12-421-015`
Alternative APN	`08-12-421-015-0000`

Interior

Bedrooms	3 Beds
Full Baths	1.5 Baths
Half Baths	1 Half Bath
Total Rooms	6 Rooms
Stories	1 Story
Building Area	1,254 sqft Living Area
1st Floor Area	1,254 sqft
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1958
Effective Year Built	Effective 1958
Architectural Style	Bungalow
Exterior Material	Brick/Stone
Construction Type	Frame
Roof Material	Asphalt
Lot Area	8,448 sqft (0.194 acres)
Garage Type	Attached
Parking Spaces	1 Parking Space

Utilities, Heating & Cooling

Cooling System	Central
Heating System	HVAC
Water Source	Commercial

Location & Zoning

Street Address	512 S WILLIAM ST
City	MOUNT PROSPECT
State	IL
Zip	60056-3955
Property Category	Residential
Property Type	Residential > Single Family > Home
Legal Description	(ELLENDALE)(EAST) SUB OF S 30 ACS OF W 40ACS IN DIVIS ION OF SE SEC 12-41-11
Legal Range	11E
Legal Township	41N
Legal Section	12
Legal Subdivision	ELLENDALE EAST
Legal Lot Number	72
Jurisdiction	COOK IL
Township / Civil Division	ELK GROVE
Census Block Group	3
Census Block	3012
Census Tract	804901

Owner

Source: Cook County records, as of May 27, 2026

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

Owner of Record	Individual Name on Record
Mailing Address	512 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Occupancy	Owner Occupied
Owner Type	Individual

Deeds, Mortgages & Sale History

Date	Document
Sep 21, 2021	Deed of Trust, Mortgage · Conventional Mortgage FLAGSTAR BANK FSB
Feb 14, 2019	Deed of Trust, Mortgage GUARANTEED RATE
Jul 24, 2017	Deed of Trust, Mortgage · Conventional with PMI GUARANTEED RATE

Assessor's Deed Record

Deed Names	Name on Deed
Last Sale	Jul 24, 2007 · Amount on Record
Deed Sale	Jul 24, 2007 · Amount on Record
Deed Document Number	200735118
Prior Transfer Date	Dec 20, 2006
Prior Transfer Doc	0000049005
Record Updated	Oct 29, 2026

September 2021: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	COOK IL
Property Address	512 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Transaction Type	Mortgage
Record Updated	Sep 30, 2021

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	0026428469
Date	Sep 21, 2021
Instrument	2126428469

Lender

Name	FLAGSTAR BANK FSB
Type	Bank
Address	TROY, MI 48098

Agreement

Type	Conventional Mortgage
Amount	Amount Recorded
Term	239 Months
Due	Aug 1, 2041

Interest

Rate Type	Fixed Rate
Rate	3.03%

February 2019: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	COOK IL
Property Address	512 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Document Number	1905249063
Instrument Date	Feb 14, 2019
Transaction Type	Mortgage
Record Updated	Mar 4, 2019
Title Company	ROCKFORD TITLE COMPANY, ROCKFORD TITLE CO

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Husband and Wife
Address	512 S WILLIAM ST MOUNT PROSPECT IL 600563955, MOUNT PROSPECT, IL 60056-3955

Mortgage

Document Number	1905249063
Date	Feb 21, 2019
Instrument	5249063

Lender

Name	GUARANTEED RATE
Address	CHICAGO, IL 60613

Agreement

Amount	Amount Recorded
Term	360 Months
Due	Feb 20, 2049

Interest

Rate Type	Fixed Rate

July 2017: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	COOK IL
Property Address	512 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Document Number	1721216235
Instrument Date	Jul 24, 2017
Transaction Type	Mortgage
Record Updated	Aug 15, 2017
Title Company	RAVENSWOOD TITLE

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Tenants by the Entirety
Address	512 S WILLIAM ST MOUNT PROSPECT IL 600563955, MOUNT PROSPECT, IL 60056-3955

Mortgage

Document Number	1721216235
Date	Jul 31, 2017
Instrument	21216235

Lender

Name	GUARANTEED RATE
Address	CHICAGO, IL 60613

Agreement

Type	Conventional with PMI
Amount	Amount Recorded
Term	180 Months
Due	Jul 30, 2032

Interest

Rate Type	Fixed Rate
Rate	3.37%

Tax Assessment & Valuation

Source: Cook County assessment roll, as of May 27, 2026

Property Jurisdictions

Type	Name
State	Illinois
County	Cook County
County Subdivision	Elk Grove Township
Municipality	Mount Prospect Village
Secondary School District	Township High School District 214 (09 - 12)
Elementary School District	Mount Prospect School District 57 (PK - 08)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2025		$39,000 (+26.08%) Land $10,138 Building $28,862	$390,000 (+26.08%) Land $101,380 Building $288,620
2023	$7,693.00 (+4.41%)
2022	$7,368.00 Homeowner's exemption	$30,932 Land $8,448 Building $22,484	$309,320 Land $84,480 Building $224,840

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 February 11, 2026 · 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
Community Rating System	Class 6 (20% premium discount)
Nearby Flood Policies	2 in force
Nearby Flood Claims	6 (1987–2007)
Claims Outside the SFHA	2 of 6
Most Recent Claim	Aug 2007 · Severe Storms And Flooding
Claims by Event	Severe Storms & Flooding, Aug 1987 · 3 claims

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	Not rated no burnable land within 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	MOUNT PROSPECT serves 41,000 people · EPA ID IL0311980
Water Source	Purchased surface water from NORTHWEST SUBURBAN MUNICIPAL JAWA
Last State Inspection	Aug 2025
Lead	2 ppb (2026–2028) action level 15 ppb

Violations Reported to EPA

Water Quality	None last 10 years
Treatment and Procedure	None last 10 years
Monitoring and Reporting	11 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. The service area is an EPA estimate; the actual supplier may differ.

Internet Providers

Source: FCC Broadband Data Collection, based on 671 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
AT&T Fiber · DSL in parts of the area	5,000 / 5,000
Xfinity Cable	2,000 / 250
Astound Broadband Cable	1,500 / 50
Verizon Fixed Wireless	1,000 / 75

May also be available: T-Mobile.

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