Cost to Build a House in Washington County, Oregon
Building a house in Washington County, Oregon costs about $227/sq ft in 2026 — roughly $399,520–$508,480 for a 2,000 sq ft mid-range home (construction only, land excluded). 1,646 single-family homes were permitted here in 2025, and the typical existing home is worth $572,565. Population: 610,000.
That applies a local adjustment of +8% to the Oregon average of $210/sq ft.
How much building happens in Washington County
Single-family homes permitted each year, 2000–2025. 2025 is highlighted; the 2008–2011 crash years are darker.
Washington County is building 57% fewer homes than it did before the crash, up from a low of 871 in 2009. A thinner builder market can mean fewer bids and longer waits for specialist trades.
U.S. Census Bureau Building Permits Survey, county annual files 2000–2025 (1-unit structures, total including imputation).
Build or buy in Washington County?
Building a median-size new home in Washington County costs about $169,237 more than buying the typical existing one. That gap is narrower than the Oregon average of +34.6%, because existing homes here are pricier than in much of the state.
The two sides are not the same product: the build is brand new at the median new-home size for the West, the existing home is typically older and smaller. Lot cost uses Oregon's average land share, and local lot prices can be well above or below it. Full Oregon build-vs-buy comparison
Existing home value: Zillow Home Value Index, single-family, middle tier (2026-08) — an index of typical value, not a median sale price. Land: FHFA Working Paper 19-01.
What builders declared on Washington County permits (2025)
The average declared valuation was $370,867 per home, against our $454,000 estimate for a 2,000 sq ft mid-range build. The two measure different things: builders declare a valuation for permit-fee purposes, which routinely understates finished cost, and permits cover homes of every size and finish level. We show both because quoting only the flattering one would be dishonest.
Source: U.S. Census Bureau Building Permits Survey, 2025 annual data.
Local Market Factors
- ›Portland suburb/Silicon Forest
- ›Tech industry drives costs
What building in Washington County actually involves
Cost per square foot is one number. These are the conditions behind it.
How busy this market is
Washington County ranks 1st of 35 counties in Oregon for single-family permits issued in 2025, accounting for 17.9% of all the single-family homes permitted statewide that year.
That puts it among the busiest building markets in the state — deep contractor supply, but also the most competition for their time.
U.S. Census Bureau Building Permits Survey, co2025a.txt (2025).
What land adds on top
Land averages 36.1% of finished property value in Oregon, which is a markup of about 56% on construction cost. For the $454,000 build above, that implies roughly $254,240 for the lot.
This is a statewide figure. Lots inside Washington County's built-up areas will run above it and rural parcels below, so treat it as an order of magnitude rather than a budget line.
FHFA Working Paper 19-01 land values.
What the trades cost
Median hourly wage, Oregon. BLS Occupational Employment and Wage Statistics, May 2025.
Climate, spec and timing
- 5,121 heating and 313 cooling degree days a year in Oregon — heating drives the mechanical budget. (NOAA, 2016-2025 average)
- The median new home in the West is 2,090 sq ft and the Census median contract price there is $176.87/sq ft, excluding land — the same basis as our estimate above. (Census Survey of Construction 2025)
- Statewide, permit filings peak in March and bottom out in November. Contractors have the most capacity in the quiet months.
- Oregon issued 9,215 single-family permits in 2025 overall. See the 35-year state history.
Cost by Home Size in Washington County
| Home Size | Basic | Mid-Range | Premium |
|---|---|---|---|
| 500 sq ft | $83,918 | $113,500 | $154,553 |
| 1,000 sq ft | $167,835 | $227,000 | $309,106 |
| 1,500 sq ft | $251,753 | $340,500 | $463,660 |
| 2,000 sq ft | $335,670 | $454,000 | $618,213 |
| 2,500 sq ft | $419,588 | $567,500 | $772,766 |
| 3,000 sq ft | $503,505 | $681,000 | $927,319 |
| 4,000 sq ft | $671,340 | $908,000 | $1,236,426 |
| 5,000 sq ft | $839,176 | $1,135,000 | $1,545,532 |
Other Oregon counties
Costs are estimates only and represent construction costs, excluding land, architect fees, permits, and landscaping. Land in Oregon averages 36.1% of finished property value (FHFA), which adds roughly 56% on top of these construction figures.
County multiplier of 1.08× applied to the Oregon state average (which itself is 1.12× the national average of $188/sq ft).
Cost data: HouseBuildCalc Permit Cost Index (876,000+ building permits, 1,700+ ZIP codes), U.S. Census Bureau Survey of Construction, BLS Producer Price Index, NAHB Cost of Constructing a Home (published summaries). County-level multipliers are estimates derived from regional market data. County permits: U.S. Census Bureau Building Permits Survey. Home values: Zillow Home Value Index. For planning purposes only.