Boulder County property record for 405 S 43rd St, Boulder, CO 80305
| Property Type | Single Family Home |
|---|---|
| Details | 4 bd · 1.75 ba · 2,162 sqft · built 1957 |
| Lot Size | 0.176 acres (7,647 sqft) |
| Owner | 2 Individual Names on File |
| Last Sale | $850,000 (Apr 2026) |
| Tax Bill | $5,780 (2025) |
| Deeds & Mortgages | Apr 2026 Sale & Mortgage |
| Flood Zone | Zone X (minimal risk) |
| APN | 1577-05-4-25-022 |
| Primary APN | 1577-05-4-25-022 |
|---|---|
| Alternative APNs |
|
| Bedrooms | 4 Beds |
|---|---|
| Full Baths | 1.75 Baths |
| Half Baths | 1 Half Bath |
| Total Rooms | 8 Rooms |
| Stories | 1 Story |
| Building Area | 2,162 sqft Living Area |
| Gross Area | 2,700 sqft |
| 1st Floor Area | 1,150 sqft |
| Basement Area | 1,350 sqft |
| Finished Basement | 1,012 sqft |
| Unfinished Basement | 338 sqft |
| Interior Walls | Wallboard/Drywall |
| Year Built | Built 1957 |
|---|---|
| Effective Year Built | Effective 1994 |
| Architectural Style | Ranch |
| Exterior Material | Brick Veneer |
| Construction Type | Masonry / Concrete Block |
| Roof Material | Asphalt |
| Lot Area | 7,647 sqft (0.176 acres) |
| Garage Type | Attached |
| Garage Area | 200 sqft |
| Parking Spaces | 1 Parking Space |
| Patio Area | 250 sqft |
| Heating System | Forced Air with A/C |
|---|
| Account Number | R0011432 |
|---|---|
| Street Address | 405 S 43RD ST |
| City | BOULDER |
| State | CO |
| Zip | 80305-6007 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Legal Description | LOT 22 BLK 8 MARTIN ACRES 2 |
| Legal Range | 70 |
| Legal Township | 1S |
| Legal Section | 05 |
| Legal Subdivision | MARTIN ACRES 2 - BO |
| Legal Block | 8 |
| Legal Lot Number | 22 |
| Jurisdiction | BOULDER CO |
| Township / Civil Division | BOULDER |
| Census Block Group | 3 |
| Census Block | 3009 |
| Census Tract | 12507 |
405 S 43rd St is owned and occupied by two individuals who bought it in April 2026.
Source: Boulder County records, as of September 18, 2026
| Owner of Record | 2 Individual Names on File |
|---|---|
| Mailing Address | 405 S 43RD ST, BOULDER, CO 80305-6007 |
| Occupancy | Owner Occupied |
| Owner Type | Individual |
| Vesting | Joint Tenants |
Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.
| Deed Names | 2 Names on Deed |
|---|---|
| Last Sale | Apr 27, 2026 · Amount on File |
| Deed Sale | Apr 27, 2026 · Amount on File |
| Prior Sale | Jul 9, 2012 · Amount on File |
| Deed Document Number | 20264129297 |
| Prior Transfer Date | Apr 1, 2008 |
| Prior Transfer Doc | 0002926511 |
| Record Updated | Oct 29, 2026 |
| Document Type | Warranty Deed |
|---|---|
| Jurisdiction | BOULDER CO |
| Recording Date | Apr 27, 2026 |
| Property Address | 405 S 43RD ST, BOULDER, CO 80305-6007 |
| Document Number | 0004129297 |
| Instrument Date | Apr 24, 2026 |
| Instrument | 2026.4129297 |
| Transaction Type | Transfer |
| Record Updated | May 6, 2026 |
| Title Company | LAND TITLE |
| Amount | Amount on Record |
|---|---|
| Downpayment | Downpayment on Record |
| Loan-to-Value (LTV) | LTV on Record |
| Tax | $8,585.00 |
| Amount Accuracy | Calculated from Transfer Tax |
| Additional |
|
| Name | Verified Name |
|---|
| Name | Verified Name |
|---|---|
| Relationship | Joint Tenants |
| Address | 405 S 43RD ST, BOULDER, CO 80305-6007 |
| Document Number | 0004129298, |
|---|---|
| Date | Apr 27, 2026 |
| Instrument | 2026..4129298 |
| Name | UNITED WHOLESALE MORTGAGE |
|---|
| Type | Conventional Mortgage |
|---|---|
| Amount | Amount on Record |
| Term | 360 Months |
| Due | May 1, 2056 |
| Rate Type | Fixed Rate |
|---|---|
| Rate | 6.11% |
| Initial Type | Fixed Rate |
| Max Rate | -1% |
The 2025 property tax bill for 405 S 43rd St was $5,780, up 0.9% from the year before.
Source: Boulder County assessment roll, as of September 18, 2026
| Type | Name |
|---|---|
| State | Colorado |
| County | Boulder County |
| Municipality | Boulder City |
| Unified School District | Boulder Valley School District RE-2 (PK - 12) |
| Year | Tax Bill | Assessed Value | Assessed Market Value |
|---|---|---|---|
| 2026 | $60,275 (+0.83%) Land $34,476 Building $25,799 | $956,400 (-) Land $577,000 Building $379,400 | |
| 2025 | $5,780.00 (+0.87%) | $59,776 Land $36,063 Building $23,713 | $956,400 Land $577,000 Building $379,400 |
| 2024 | $5,730.00 (+1.79%) | ||
| 2023 | $5,629.00 (+13.58%) | $67,998 (+29.35%) Land $42,257 Building $25,741 | $1,014,900 (+34.18%) Land $630,700 Building $384,200 |
| 2022 | $4,956.00 | $52,570 Land $31,345 Building $21,225 | $756,400 Land $451,000 Building $305,400 |
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.
FEMA maps place 405 S 43rd St in Zone X, an area of minimal flood risk, though there have been 7 flood claims nearby since 1979.
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 | 6 in force |
| Nearby Flood Claims | 7 (1979–2022) |
| Claims Outside the SFHA | 5 of 7 |
| Most Recent Claim | Jul 2022 · rainfall accumulation |
| Claims by Event |
|
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 risk around 405 S 43rd St is low, with a 0.03% annual chance of wildfire.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Low lower than 80% of the US · lower than 91% of Colorado |
|---|---|
| Wildfire Likelihood | 0.03% annual chance |
| Exposure | None beyond ember reach |
Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.
Source: EPA Safe Drinking Water Information System, as of September 2026
| Water System | CITY OF BOULDER serves 166,080 people · EPA ID CO0107152 |
|---|---|
| Water Source | Surface water |
| Last State Inspection | Sep 2024 |
| Lead | 2 ppb (2023–2025) action level 15 ppb |
| Water Quality | Haloacetic acids resolved · Jul 2017 |
|---|---|
| Treatment and Procedure | None last 10 years |
| Monitoring and Reporting | 1 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.
Source: FCC Broadband Data Collection, based on 678 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Ayva Networks Fixed Wireless | 2,500 / 2,500 |
| CenturyLink Fiber · DSL in parts of the area | 2,000 / 1,000 |
| Xfinity Cable | 2,000 / 250 |
| Verizon Fixed Wireless | 300 / 20 |
| LiveWireNet Fixed Wireless | 250 / 100 |
| T-Mobile Fixed Wireless | 100 / 20 |
May also be available: AT&T.
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