403 W William St, Superior (Louisville), CO 80027 Property Records

Boulder County property record for 403 W William St, Superior, CO 80027

Property Summary

Property Type	Single Family Home
Lot Size	0.316 acres (13,765 sqft)
Owner	Trust Name on File
Last Sale	$1,684,250 (Feb 2024)
Tax Bill	$443 (2023)
Deeds & Mortgages	Jul 2018 Transfer
Flood Zone	Zone X (minimal risk)
APN	`1577-24-0-06-002`

Property Details

APN / Parcel Number

Primary APN	`1577-24-0-06-002`
Alternative APNs	`R0029293` `0029293`

Exterior

Lot Area	13,765 sqft (0.316 acres)
Total Buildings	2 Buildings

Location & Zoning

Account Number	R0029293
Old Parcel Number	0029293
Street Address	403 W WILLIAM ST
City	SUPERIOR
State	CO
Zip	80027-9649
Property Category	Residential
Property Type	Residential > Single Family > Home
Local Zoning Code	1135
Legal Description	LOTS 11-12 BLK Q SUPERIOR WEST
Legal Range	70
Legal Township	01S
Legal Section	24
Legal Subdivision	SUPERIOR WEST - SP
Legal Block	Q
Legal Lot Number	11-12 12
Jurisdiction	BOULDER CO
Township / Civil Division	BOULDER
Census Block Group	1
Census Block	1020
Census Tract	60602

Owner

403 W William St is owner-occupied and held in a trust since February 2024.

Source: Boulder County records, as of March 22, 2024

Owner of Record	Trust Name on File
Mailing Address	403 W WILLIAM ST, SUPERIOR, CO 80027-9649
Occupancy	Owner Occupied
Owner Type	Company
Vesting	Trust

Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	Name on Deed
Last Sale	Feb 26, 2024 · Amount on File
Deed Sale	Feb 26, 2024 · Amount on File
Prior Sale	Jul 20, 2018
Deed Document Number	4037780
Record Updated	Jun 7, 2026

July 2018: Quit Claim Deed, Transfer

Document Type	Quit Claim Deed
Jurisdiction	BOULDER CO
Recording Date	Jul 20, 2018
Property Address	109 4TH AVE, SUPERIOR, CO 80027-1687
Document Number	0003667074
Instrument Date	Jul 20, 2018
Instrument	3667074
Transaction Type	Transfer
Record Updated	Jul 27, 2018

Transaction

Tax	$0.00
Additional	Quitclaim Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Joint Tenants with Right of Survivorship
Address	109 4TH AVE SUPERIOR CO 800271687, SUPERIOR, CO 80027-1687

Tax Assessment & Valuation

Source: Boulder County assessment roll, as of August 25, 2023

Property Jurisdictions

Type	Name
State	Colorado
County	Boulder County
Municipality	Superior Town
Unified School District	Boulder Valley School District RE-2 (PK - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2023	$443.00 (-56.74%)	$8,020 (-17.28%) Land $8,020	$119,700 (-14.19%) Land $119,700
2022	$1,024.00	$9,695 Land $9,695	$139,500 Land $139,500

Assessed value is set for property tax purposes, not a market price estimate; it is a fraction of this property's market value.

Flood

FEMA maps place 403 W William St in Zone X, an area of minimal flood risk, though there have been 1 flood claim nearby since 2013.

Source: FEMA National Flood Hazard Layer, effective October 14, 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 5 (25% premium discount)
Nearby Flood Policies	3 in force
Nearby Flood Claims	1 (2013)
Most Recent Claim	Sep 2013 · Severe Storms, Flooding, Landslides, And Mudslides

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

Wildfire risk around 403 W William St is moderate, ranking above 64% of the US, with a 0.3% annual chance of wildfire.

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

Wildfire Risk	Moderate above 64% of the US · above 55% of Colorado
Wildfire Likelihood	0.3% annual chance
Exposure	Indirect within ember reach
Adjoins Burnable Land	Yes

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	SUPERIOR MD NO 1 serves 17,900 people · EPA ID CO0107725
Water Source	Surface water
Last State Inspection	Feb 2025
Lead	Under 1 ppb (2023–2025) action level 15 ppb

Violations Reported to EPA

Water Quality	Treatment failure resolved · Dec 2021
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 225 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
Xfinity Cable	2,000 / 2,000
CenturyLink Fiber · DSL in parts of the area	2,000 / 1,000
LiveWireNet Fixed Wireless	250 / 100