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Addison, Texas
Inside Addison's city limits, shrink-swell clay limits houses without basements on 28% of mapped land. A shallow water table limits basements on under 1%.
That clay share is below Dallas County's 51%. FEMA's flood data list 14 flood losses since 2016 in the 2 ZIP codes overlapping the city. Of its 11,369 homes, 12% were built before 1980; the median dates from 1998.
Data as of October 13, 2026 · sources · in Dallas County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 2 overlapping ZIPs
of homes built before 1980
Foundation repair in Addison
Foundation repair in Addison: shrink-swell clay limits slab homes on 28% of Addison's mapped land.
About 1,400 of Addison's 11,369 homes are detached houses.
| Who designs the repair | The ASCE Texas Section's repair guidelines say a Texas-licensed engineer should evaluate the foundation and design the repair (2022 guidelines) |
| Prices | Cost guide ranges compared |
Soil under Addison city limits
| Expansive clay (limits slab homes) | 27.7% |
| High water table (limits basements) | 0.1% |
| Septic fields very limited | 85.8% |
| Clay swell (LEP, by area) | 6.7% |
| High-swell land (LEP 6%+) | 25.5% |
| Urban land, not rated | 24.6% |
| Mapped soil | 2,788 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Stephen | 27% | n/a |
| Dalco | 12% | n/a |
| Houston Black | 9% | 91% |
| Austin | 9% | 93% |
| Eddy | 6% | 0% |
| Frio | 1% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 6.7% by land area here, and 25% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 28% of the mapped land.
Clay shrinks as it dries: 100% of Dallas County is in drought on the latest map, and 28% of Addison's mapped land has shrink-swell clay.
USDA rates 86% of the land very limited for septic absorption fields.
Drought in Dallas County
100% of Dallas County is in drought (D1 or worse) on the October 13, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Addison. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 75001 | 85% | 3 | $8,234 |
| 75254 | 14% | 11 | $402,106 |
Homes in Addison
| Housing units | 11,369 |
| Median year built | 1998 |
| Built before 1980 | 12% |
| Built 2000 or later | 46% |
| Owner-occupied | 18% |
| Median value, owner-occupied | $482,000 |
| Single-family detached | 13% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Farmers Branch | 4 mi | 45% | 3% |
| Carrollton | 4 mi | 65% | 8% |
| Hebron | 6 mi | 66% | 0% |
| Richardson | 7 mi | 52% | under 1% |
| Plano | 8 mi | 75% | under 1% |
| University Park | 8 mi | 33% | 0% |
| Coppell | 9 mi | 58% | 11% |
| Highland Park | 9 mi | 35% | under 1% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status