Bolthole Index

Adams County, Washington

Building permits, zoning and land rules in Adams County, Washington

40Index Score / 100
#35 of 39 in Washington

Building permits are required for building projects in unincorporated Adams County, Washington, and the county Building Department reviews the applications.1 Adams County also administers local zoning, while Environmental Health handles septic permitting and inspections.23

At a glance

Building permit
Required for building projects in unincorporated Adams County1
Zoning
County zoning and land-use review apply2
Septic
Adams County Environmental Health administers septic permits and inspections34
RV living
RV parks cap occupancy; private-land residential use remains unconfirmed5
Tiny home
Allowed conditionally where single-family housing is allowed6
Owner-builder
A conditional contractor-registration exemption exists, but permits still apply7
Minimum home size
State code sets interior-space minimums; confirm any zoning standard with Planning8

Who to call

Building permits

Adams County Building & Planning

Building permits, plan review, inspections and planning questions

509-488-9441

449 E Cedar Boulevard Othello, WA 99344

Online permits →

Septic permits

Adams County Health Department

On-site sewage site registration and sewage-permit applications

(509) 488-2031

425 E MAIN STE 700, OTHELLO, WASHINGTON 99344

Roads & driveways

Adams County Public Works

County-road maintenance and approach questions

(509) 659-3276

publicworks@co.adams.wa.gov

210 W. Alder Ave. Ritzville, WA 99169

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Off-grid gear

Going off-grid in Adams County means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Adams County, Washington?

Yes. The Adams County Building Department reviews permit applications for building projects in unincorporated Adams County and in Lind, Hatton and Washtucna; town projects need town approval before county submittal, while Othello and Ritzville are outside this review scope.1 Permits generally cover new homes, mobile-home moves, repairs, additions, plumbing, reroofing, replacement windows, solid-fuel stoves and gas inserts.9

County submittals must be complete for acceptance and include the application, site plan, complete construction drawings, design criteria and fee information.10 The county publishes a master fee schedule, but the amount depends on the application, so confirm the total with Building & Planning.11 County-reviewed work follows the 2021 Washington State Codes, including the state Energy Code, in effect since March 15, 2024, and receives inspections through the phases of construction.121314 The county's inspection page notes that inspections called in after 4 p.m. will not be scheduled for the next day.15 Confirm any exemption before starting work.

Who issues building permits in Adams County, and how do you reach them?

Adams County Building & Planning is the first stop for a project in the county building jurisdiction. The Building Division enforces the Washington State Building Code, and its Othello office handles questions by phone at the contact listed above.16 Building-permit applications can go through CloudPermit, and every submittal must be complete for acceptance.10

The Building Division reviews plans and performs inspections through construction, while Planning handles zoning, subdivisions and parcel-specific land-use questions.14217 A Washington owner may qualify for a contractor-registration exemption when working on their own property, unless the work is for selling, demolishing or leasing the property; the exemption covers contractor registration only, not building, electrical, plumbing or septic permits.187 For permit records, contact Building & Planning with the parcel number and property address.

Does Adams County have zoning?

Yes. Adams County administers zoning and land-use controls in unincorporated areas, while incorporated municipalities may administer separate rules.2 The mapped district matters: rural-district minimum lot areas range from 1 acre in R-1 to 20 acres per dwelling in R-20.19 Rural residential setbacks are also district-specific; front setbacks are 25 feet in R-1 through R-2.5 and 50 feet in R-5 and R-20, with other setbacks and special rules also applying.20

Ask Planning to confirm the current table and parcel zoning before designing because the cited dimensional document is marked as a draft.2019 Accessory dwelling units may be allowed on residential-zoned lots with an existing or proposed single-family dwelling, subject to county conditions.21 An ADU must be at least 400 square feet, with one ADU per legal lot, though tiny-home ADUs are excepted from that minimum; the usual maximum is 1,000 square feet, rising to the lesser of 1,500 square feet or 65% of the main home's living area on lots of 2.5 acres or more22. An attached ADU shares the main home's septic and water system unless the Adams County health department issues a separate septic permit22. We could not confirm a universal minimum size for a main dwelling, lot-coverage limit or height limit, or a general agricultural-building exemption, so take those questions to Building & Planning. The county publishes its zoning code and map, last updated August 2025, covering rural, agricultural, residential and rural-settlement districts.23 Dividing land is regulated too: the Planning Division processes short plats, and a short-plat application needs water-availability and septic or sewer documentation.24

How do septic permits work in Adams County?

Adams County Health Department's Environmental Health program reviews septic plans and administers liquid-waste permitting, compliance and inspections.3 A residence needs a septic permit or Existing System Evaluation unless city or community sewer is available, in which case the sewer provider's availability letter is required.2526 The county's site-registration form can accompany a sewage-permit application and compliant system design.27

For permitted on-site sewage work, the local health officer inspects during site evaluation, construction or final construction and confirms the finished system against the approved design.4 About 41% of mapped county soils lack severe limits for a conventional drain field, so a parcel-level evaluation matters before purchase.28 Adams County's short-term-rental rule permits compliant septic rather than requiring a public-sewer connection, but it ties occupancy to septic design capacity; the county's broader rules for alternative off-grid sanitation could not be confirmed.2930

Can you live in an RV or tiny home on land in Adams County?

Adams County allows tiny-home construction and habitation under conditions in residential districts where single-family housing is allowed.6 A tiny home used as a single-family dwelling must meet that zone's single-family requirements, while a tiny home used as an accessory dwelling follows the county's ADU rules with an exception to the ADU minimum-size provision.6 Take the parcel number and proposed unit to Building & Planning before ordering it.

In an Adams County RV park, an RV may occupy the park for no more than 180 consecutive days or 180 calendar days in a year.5 A campground or RV park may use one manufactured home as a caretaker residence, but no other manufactured home may be occupied, stored or parked there.31 Neither rule answers whether an owner may live long-term in an RV on an ordinary private parcel; ask Planning before relying on an RV for housing or temporary camping.

If you plan to place a manufactured home, note the county's age rule: as of August 19, 2025, new manufactured-home placements must be greater than 20 years old, measured from the Washington Department of Labor and Industries approval date, and a used home moved in from elsewhere needs an L&I fire-life-safety inspection.32 Because the wording is easy to misread, confirm the exact requirement for your unit with Building & Planning before buying a home to move.

Building a home in Adams County: what are the steps?

  1. Ask Adams County Planning to identify the parcel's zoning district and confirm the use, minimum lot area, setbacks and site layout.21920
  2. Confirm potable water and wastewater service; a residence needs a septic permit or Existing System Evaluation unless an available city or community sewer provides an availability letter.2526
  3. Resolve access with Public Works. New county construction needs a road-approach permit and Fire Marshal approval; state-highway access needs state approval.33
  4. Prepare the application, site plan, complete construction drawings, design criteria and fee information; incomplete submittals are not accepted.10
  5. Submit to Building & Planning and complete inspections through the construction phases.14
  6. If the site lies in a frequently flooded area within shoreline jurisdiction, meet the county flood-hazard provisions before development.34 Ask Building & Planning whether the project needs a certificate of occupancy because we could not confirm a general county rule.

What should you check before buying land in Adams County?

Start with zoning, legal access, water and septic rather than relying on the listing description. Adams County publishes a zoning map and code, while Environmental Health evaluates sewage issues for land development.3536 A private-well permit or approval path could not be confirmed, so ask Environmental Health and the applicable state water office before assuming a well can serve the parcel.

Check the driveway early. A county driveway may serve no more than 2 residences; one longer than 150 feet must be at least 20 feet wide with an approved fire-apparatus turnaround, while one shorter than 150 feet must be at least 16 feet wide.37 Development in frequently flooded areas within shoreline jurisdiction must follow county flood-hazard provisions.34 A short-term rental also needs county review, a safety inspection and compliant sewer or septic service.38 The effective property-tax rate is about 0.8%, and the median annual bill is about $2,104.3940

Watch-outs

  • The RV-park occupancy limit does not establish a private-land residential RV rule, so ask Adams County Planning before buying land for RV living or temporary camping.5
  • Only about 41% of mapped soils lack severe limits for a conventional septic drain field, so complete site evaluation before treating a parcel as buildable.28
  • A long county driveway can trigger width and fire-apparatus turnaround requirements that materially affect site cost.37

Sources

  1. Permitting, quoted and re-checked
  2. Planning Division, quoted and re-checked
  3. Environmental Health, quoted and re-checked
  4. WAC 246-272A-0260 Inspection, quoted and re-checked
  5. Adams County Zoning Code, quoted and re-checked
  6. ecode360.com, quoted and re-checked
  7. RCW 18.27.090 Exemptions, quoted and re-checked
  8. WAC 51-50-1208 — Section 1208—Interior space dimensions (Washington statewide rule), quoted and re-checked
  9. Building Division Frequently Asked Questions, quoted and re-checked
  10. Permitting, quoted and re-checked
  11. Planning Division, quoted and re-checked
  12. Building Division, quoted and re-checked
  13. Building Division, quoted and re-checked
  14. Building Division, quoted and re-checked
  15. Building Division, quoted and re-checked
  16. Adams County Building & Planning (co.adams.wa.gov)
  17. Planning Division, quoted and re-checked
  18. RCW 18.27.090 Exemptions, quoted and re-checked
  19. Adams County Zoning Map & Codes, quoted and re-checked
  20. Adams County Zoning Map & Codes, quoted and re-checked
  21. ecode360.com, quoted and re-checked
  22. Chapter 17.69 Specific Uses and Standards — Adams County, WA, quoted and re-checked
  23. Adams County Zoning Map & Codes, quoted and re-checked
  24. Planning Division, quoted and re-checked
  25. co.adams.wa.gov, quoted and re-checked
  26. co.adams.wa.gov, quoted and re-checked
  27. Adams County Health Department (co.adams.wa.gov)
  28. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  29. Adams County Zoning Code, quoted and re-checked
  30. Adams County Zoning Code, quoted and re-checked
  31. Adams County Zoning Code, quoted and re-checked
  32. co.adams.wa.gov, quoted and re-checked
  33. co.adams.wa.gov, quoted and re-checked
  34. Ordinance O-02-2023, Adams County Shoreline Master Program, quoted and re-checked
  35. Adams County Zoning Map & Codes, quoted and re-checked
  36. Environmental Health, quoted and re-checked
  37. co.adams.wa.gov, quoted and re-checked
  38. Adams County Zoning Code, quoted and re-checked
  39. Effective property tax rate: Bolthole Index county data
  40. Median property tax bill: Bolthole Index county data

Written October 10, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

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Compared with neighboring counties

Like all 6 of its neighbors, Adams County requires a building permit for a home.

RuleAdams CountyLincoln CountyWhitman CountyFranklin CountyGrant CountyWalla Walla CountySpokane County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesYes
Septic permitsCounty Health Dept.County Public HealthCounty Public HealthBenton-Franklin Health DistrictCounty Health DistrictCounty Dept. of Community HealthSpokane Regional Health District

County locator

Adams County in Washington

40
County map
Adams County highlighted among the Washington counties · colored by Index score

How Adams County scores

Seclusion62100% ev.
Self-Sufficiency1492% ev.
Admin Boringness41100% ev.
Durability65100% ev.
Property Autonomy50100% ev.
Carry Cost81100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$310kTypical home
0.8%Property tax
$2,133Land / acre
11.5"Annual rain
13.6% of yrsSevere drought
13.7 / yr (+10.2)Mid-century 100°F days
37.6 daysMid-century dry spell
0.49" (+6.6%)Mid-century 1-day rain
1.16×Wildfire change factor
100%Forward climate coverage
$1,384Home insurance / yr
2% / yrInsurance growth
0.8%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
15,347People within 30 min
1,614,770People within 2 hr
2,912Radius comparison (15 mi)
10.8People / sq mi
1.8%Federal land
69.3%Land at 15% slope or less
41%Soils rated "not limited" for septic (strict USDA rating)
503,582 acWorkable land screen
0.7%Wooded land
49.6°FAvg temp

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Cities and towns in Adams County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Town of Hatton · Town of Washtucna

Answers from the rulebook for Adams County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Adams County rules

  • Building permitRequired

    Construction work reviewed by Adams County Building Division.

    • The county FAQ says generally all types of construction work require permits, including new homes, mobile-home moves, repairs, additions, plumbing, reroofing, window replacement, wood/pellet stove installations, and gas inserts.
    • Jurisdictional submission differs for unincorporated areas, specified towns, and cities.
    “Generally all types of construction work including: new homes, mobile home moves, repairs and additions, plumbing, re-roofing, window replacement, wood/pellet stove installations, and gas inserts.”
    One more reviewed finding on this topic
    • Required — Building projects in unincorporated Adams County and the Towns of Lind, Hatton, and Washtucna.
      “The Building Department reviews permit applications for all building projects in the unincorporated areas of Adams County as well as the Towns of Lind, Hatton and Washtucna.”
  • Building code adoptedAdopted (with conditions)

    Building projects reviewed by Adams County Building Division.

    • The county states that the 2021 Washington State Codes, including the state Energy Code, went into effect March 15, 2024.
    • Requirements may change under later local, state, or federal law, policy, or code cycles.
    “2021 WA BUILDING CODE EFFECTIVE MARCH 15, 2024”
    One more reviewed finding on this topic
    • Adopted (with conditions) — Building work reviewed by Adams County Building Division.
      “As of March 15, 2024 the 2021 Washington State Codes, including the state Energy Code went into effect. All submittals will be reviewed for compliance with the 2021 State Codes as adopted.”
  • InspectionsRequired

    Permitted construction reviewed by Adams County Building Division.

    • The county uses certified building officials, inspectors, and plans examiners for inspections through construction phases.
    • State residential-code inspection provisions require final inspection before occupancy.
    “The county has employed International Code Council certified a Building Official, Inspectors and Plans Examiners to ensure that site inspections and construction documents are efficiently inspected and reviewed for code compliance through the various phases of construction.”
    One more reviewed finding on this topic
    • Limited — Construction reviewed by the Adams County Building Division.
      “The county has employed International Code Council certified a Building Official, Inspectors and Plans Examiners to ensure that site inspections and construction documents are efficiently inspected and reviewed for code compliance through the various phases of construction.”
  • County-wide zoningPresent (with conditions)

    Adams County land-use regulation and zoning.

    • The Planning Division maintains county zoning, the Development Code, and the Shoreline Master Program; particular rules may be area- or district-specific.
    “The Planning Division develops and maintains the County’s land use regulations, including the Comprehensive Land Use Plan, Adams County Zoning, Development Code, and Shoreline Master Program.”
  • Local zoningPresent (with conditions)

    County-administered zoning and land-use controls in Adams County.

    • This claim concerns county zoning; incorporated municipalities may administer separate municipal zoning.
    “Adams County Zoning Code and Map, updated August 2025”
    One more reviewed finding on this topic
    • Present (with conditions) — Adams County local zoning and land-use regulation, including unincorporated county areas; incorporated municipalities may administer their own local rules.
      “The Planning Division develops and maintains the County’s land use regulations, including the Comprehensive Land Use Plan, Adams County Zoning, Development Code, and Shoreline Master Program.”
  • Zoning districtsPublished (with conditions)

    Adams County zoning districts and district-specific dimensional standards.

    • The county publishes a zoning map and zoning code page updated August 2025.
    • The linked county zoning materials identify rural, agricultural, residential, rural settlement, and other zoning districts with use and dimensional standards.
    “Adams County Zoning Code and Map, updated August 2025”
    One more reviewed finding on this topic
    • Published (with conditions) — Adams County zoning districts and zoning map.
      “Adams County Zoning Code and Map, updated August 2025”
  • Minimum dwelling sizeSpecified

    Accessory dwelling units in Adams County residential zoning districts.

    • The ADU must be accessory to a single-family residence and no more than one ADU per legal lot is permitted.
    • ADUs require building permits to ensure compliance with applicable fire, health, and safety codes.
    • The 400-square-foot minimum does not apply to tiny homes used as ADUs under Section 17.69.030(B)(2).
    • The ADU must conform to the standards of the underlying zone, including lot coverage and setbacks.
    • The ordinary maximum ADU size is 1,000 square feet exclusive of uninhabitable floor area.
    • On lots of two and one-half acres or greater, the maximum is 1,500 square feet or 65% of the primary dwelling’s living area, whichever is less.
    • An attached ADU must use the same septic and water system as the primary dwelling unless a separate septic permit is obtained from the Adams County health department.

    minimum gross floor area: >= 400 square feet (Tiny-home ADUs are excepted from this minimum under Section 17.69.030(B)(2).) · maximum gross floor area: <= 1000 square feet (On lots of two and one-half acres or greater, maximum is 1,500 square feet or 65% of the primary dwelling’s living area, whichever is less.)

    “The minimum gross floor area of an ADU shall be four hundred square feet. [...] Tiny homes constructed or placed on a lot as an accessory dwelling unit (ADU) shall meet the requirements of an ADU per Section 17.69.020, with the exception of the minimum size requirement in Section 17.69.020(C)(6)(a).”
  • Minimum lot sizeDistrict specific (with conditions)

    Minimum lot area in rural zoning districts R-1, R-1.25, R-2.5, R-5, and R-20.

    • Utilities, structures, and uses including utility substations, pump stations, wells, watershed intake facilities, gas and water transmission lines, and telecommunication facilities may be permitted on newly approved lots smaller than the minimum parcel size.
    • The cited document is marked DRAFT – 4/10/25; the county zoning page identifies the zoning code and map as updated August 2025.

    R-1 minimum lot area: 1 acre (utility and similar uses may be permitted on smaller newly approved lots) · R-1.25 minimum lot area: 1.25 acres (utility and similar uses may be permitted on smaller newly approved lots) · R-2.5 minimum lot area: 2.5 acres (utility and similar uses may be permitted on smaller newly approved lots) · R-5 minimum lot area: 5 acres (utility and similar uses may be permitted on smaller newly approved lots) · R-20 minimum lot area: 20 acres per dwelling unit (utility and similar uses may be permitted on smaller newly approved lots)

    “R1 | All Uses | 1 | 100 | None R-1.25 | All Uses | 1.25 | 140 | None R-2.5 | All Uses | 2.5 | 140 | None R-5 | All Uses | 5 | 200 | None R-20 | All Uses | 20 | 330 | None”
  • SetbacksDistrict specific (with conditions)

    Residential and accessory structures in the county’s rural zoning districts R-1, R-1.25, R-2.5, R-5, and R-20.

    • New lots, structures, and additions must comply with the applicable dimensional standards and Chapter 17.76.
    • For residential uses on a legal or legally nonconforming lot of record, the administrator may reduce required setbacks only with adequate proof of hardship, and the reduction must be limited to the minimum amount needed and may not be less than the setbacks specified for shop buildings, barns, home storage facilities, and nonresidential structures.
    • The setback table notes that measurements marked with footnote 2 are from the public road right-of-way or private road easement.
    • Residential-building setbacks are subject to the table’s residential-buildings-only footnote.
    • Special setbacks may apply to lots neighboring an agricultural district under Chapter 17.42.
    • The cited document is marked DRAFT – 4/10/25; the county zoning page identifies the zoning code and map as updated August 2025.

    R-1 residential front setback: 25 feet (footnote 2) · R-1 residential street-side setback: 25 feet (footnote 2) · R-1 residential interior-side setback: 10 feet · R-1 residential rear setback: 20 feet · R-1.25 residential front setback: 25 feet (footnote 2) · R-1.25 residential street-side setback: 25 feet (footnote 2) · R-1.25 residential interior-side setback: 10 feet · R-1.25 residential rear setback: 20 feet · R-2.5 residential front setback: 25 feet (footnote 2) · R-2.5 residential street-side setback: 25 feet (footnote 2) · R-2.5 residential interior-side setback: 10 feet · R-2.5 residential rear setback: 20 feet · R-5 residential front setback: 50 feet (footnote 2) · R-5 residential street-side setback: 25 feet (footnote 2) · R-5 residential interior-side setback: 20 feet · R-5 residential rear setback: 20 feet · R-20 residential front setback: 50 feet (footnote 2) · R-20 residential street-side setback: 25 feet (footnote 2) · R-20 residential interior-side setback: 20 feet · R-20 residential rear setback: 20 feet

    “R-1 | Residential | 25² | 25² | 10 | 20 | 1 per 1 | 35 | 35³”
  • Living in an RVLimited

    Occupancy of recreational vehicles in Adams County recreational-vehicle parks.

    • RV parks are intended for visitors residing in an RV for no more than 180 days out of the year.
    • The minimum RV-park size is two acres.
    • Storage of RVs on site is prohibited unless allowed by the zoning district.
    • The cited rule governs RV parks, not all private-land RV occupancy.

    maximum occupancy: <= 180 days per year (RV parks)

    “Length of Occupancy. The period of time that an RV may occupy the park must not exceed one hundred eighty consecutive days, or one hundred eighty calendar days of a year.”
  • Tiny homesAllowed (with conditions)

    Construction and habitation of tiny homes in residential districts where single-family housing is allowed, and specified farm-worker-housing contexts.

    • A tiny home used as a single-family dwelling must meet the same requirements as a single-family dwelling in the zone, except the provisions of §17.76.070.
    • A tiny home used as an ADU must meet §17.69.020, except the ADU minimum-size requirement in §17.69.020(C)(6)(a).
    “Permit the construction and habitation of tiny homes under certain conditions in all residential districts where single-family housing is allowed.”
  • Manufactured homesLimited

    Placement and occupancy of manufactured homes in Adams County.

    • New manufactured-home placement permits require manufacturer blocking and tie-down requirements.
    • As of August 19, 2025, under ACC 17.76.070(D), all new manufactured-home placements must be greater than 20 years as measured from the Washington Department of Labor and Industries approval date.
    • Used manufactured homes older than 20 years may be permitted and placed in a designated mobile-home park, including pre-HUD homes manufactured before June 1976.
    • Used homes moved into Adams County from another Washington county or another state require a fire-life-safety inspection by the Department of Labor and Industries.
    • Reroofs and remodels to factory-assembled structures and manufactured homes require Department of Labor and Industries approval.

    new manufactured-home age: > 20 years (measured from the date of approval from the Washington Department of Labor and Industries) · rule date: 2025-08-19 (ACC 17.76.070(D))

    “As of August 19, 2025 in accordance ACC 17.76.070(D) All new Manufactured Homes placements shall be greater than 20 years, as measured from the date of approval from the WA Department of Labor and Industries.”
    One more reviewed finding on this topic
    • Limited — Manufactured-home occupancy in Adams County recreational-vehicle parks and campgrounds.
      “A manufactured home can be utilized as the caretaker’s residence; however, no other manufactured homes shall be occupied, stored, or parked in a campground or recreational vehicle park.”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units on residential-zoned lots developed with an existing or proposed single-family dwelling.

    • No more than one ADU per legal lot is stated elsewhere in the section.
    • A lot lawfully occupied by two or more single-family residences does not qualify unless short-platted under Chapter 16.32.
    • If short-platted, each ADU must meet all dimensional standards of the underlying zone and all other provisions of §17.69.020.
    “Accessory dwelling units may be allowed in all residential zoned lots developed with an existing or proposed single-family dwelling, subject to the requirements of this section.”
  • Who permits septicCounty (with conditions)

    On-site sewage and septic oversight in Adams County.

    • The county Environmental Health Department reviews sewage and septic plans, inspects systems, and administers liquid-waste permitting and compliance programs.
    “We are responsible for the oversight and compliance of the following programs to minimize public health hazards related to our environment: [...] Liquid Waste; disposal system permitting and compliance”
    One more reviewed finding on this topic
    • County (with conditions) — On-site sewage and septic programs in Adams County.
      “To protect the public's health, there are programs to provide assistance in permitting and inspecting septic systems, investigation of communicable infectious diseases, investigation of food-borne illness reports, and providing testing and medication for tuberculosis prevention.”
  • Septic permitRequired

    Residences and land-development projects using on-site sewage systems in Adams County.

    • A residence must have a septic-system permit or Existing System Evaluation.
    • If city or community sewer is available, a sewer-provider availability letter may be submitted instead.
    • The county site-registration form states that a sewage permit application and design must meet applicable statutes, ordinances, rules, guidelines, and fees.
    “A residence must have a septic system permit or an Existing System Evaluation (ESE) from the Environmental Health Department 509-488-2031. If city or community sewer is available, an availability letter from the Sewer provider must be submitted.”
  • Off-grid sanitationLimited

    Off-grid sanitation using an on-site septic system for a short-term vacation rental.

    • The on-site septic system must comply with Adams County Health Department regulations.
    • Occupancy must be consistent with the septic system’s design capacity and wastewater type.
    “If connected to an on-site septic system, the owner is responsible for ensuring that the vacation rental occupancy is consistent with the design capacity of the on-site septic system and type of wastewater discharges allowed, and in compliance with any on-site septic system’s periodic inspection, maintenance, and reporting requirements if required by the Adams County health department.”
  • Mandatory utility hookupConditional

    Residential water and wastewater service in Adams County.

    • A residence must have a septic permit or Existing System Evaluation unless city or community sewer is available.
    • When city or community sewer is available, a sewer-provider availability letter is required.
    • Water-availability proof may not be required for additions or remodels to single-family residences.
    “A residence must have a septic system permit or an Existing System Evaluation (ESE) from the Environmental Health Department 509-488-2031. If city or community sewer is available, an availability letter from the Sewer provider must be submitted.”
    One more reviewed finding on this topic
    • Conditional — Short-term vacation-rental dwellings regulated under Adams County Code §17.69.080.
      “Connection to a public sanitary sewer or an on-site septic system that complies with Adams County health department regulations for on-site sewage systems.”
  • Subdividing landRegulated (with conditions)

    Short and long plats and other land-development projects in Adams County.

    • The county Planning Division processes subdivisions, and the Environmental Health page states that land development includes all subdivisions, short plats, and long plats.
    • Short-plat applications require water availability and septic or sewer documentation.
    “Short Plat applications involve an administrative review and decision by the Building and Planning Department. The guidelines for review are included in Chapter 16.32 of the County Code.”
    One more reviewed finding on this topic
    • Regulated (with conditions) — County subdivisions, short plats, long plats, and related land-development applications.
      “It also reviews and processes land use applications—such as special use permits, subdivisions, variances, and rezones—to ensure that proposed developments align with the County’s growth management policies and directives set by the Board of County Commissioners.”
  • Driveway accessRequired

    New construction road approaches, driveways, and access roads in Adams County.

    • The Fire Marshal must approve the driveway or access road.
    • A road-approach permit is required for all new construction, including new homes and outbuildings.
    • Remodeling, roofing, mechanical, and other listed permit types are exempt from the road-approach permit.
    • County-road approaches typically must be 330 feet from the nearest arterial road; state highways require WSDOT approval; private roads require legal ingress/egress easement documentation.

    typical county-road approach separation: >= 330 feet (Additional sight-distance requirements vary according to posted speed limits.)

    “The Adams County Fire Marshal must approve your driveway or access road (see Special Notes, below).”
    One more reviewed finding on this topic
    • Required — Private driveways serving residences in county-administered areas.
      “A driveway shall serve no more than two residences. Any County driveway hereafter created longer than 150 feet in length shall have a width of no less than 20 feet and shall provide an approved fire apparatus turnaround meeting the requirements of the IFC Appendix D. County driveways less than 150 feet in length shall have a width of no less than 16 feet a turnaround is not required.”
  • Building in a floodplainRequired

    Development within frequently flooded areas and flood-prone areas in Adams County shoreline jurisdiction.

    • Development must comply with Adams County Code Chapter 15.16, Section 18.08.560, and other applicable Shoreline Master Program provisions.
    • Frequently flooded areas include FEMA/National Flood Insurance Program one-hundred-year floodplain designations.
    • The cited SMP provisions apply within shoreline jurisdiction.

    flood probability: >= 1 percent or greater chance per year (Special Flood Hazard Areas are identified in the Adams County Flood Insurance Study and FEMA materials)

    “All development within frequently flooded areas shall comply with the protection measures designed to minimize hazards in frequently flooded areas as detailed in Adams County Code Chapter 15.16, Flood Damage and Prevention, as well as Section 18.08.560, Flood hazard reduction, and other applicable provisions of this shoreline master program.”
  • Short-term rentalsLimited

    Short-term vacation rentals in Adams County.

    • Review is Type I under Chapter 17.94.
    • The owner must obtain an Adams County Building and Planning Department inspection for egress, exits, smoke detectors, carbon-monoxide alarms, fire extinguishers, and other fire-protection systems.
    • The dwelling must connect to public sanitary sewer or a compliant on-site septic system, with septic occupancy consistent with design capacity and wastewater type.
    • All county and state regulations and requirements apply.

    short-term rental duration: fewer than 30 consecutive nights or days

    “Review of short-term rentals is a Type I process in accordance with Chapter 17.94.”
  • Permit feesPublished (with conditions)

    County building and planning permit fees.

    • The Planning Division page links a Master Fee Schedule among its applications and forms.
    • The fee amount may depend on the permit or application type.
    “Agent Authorization Form Master Fee Schedule”
    One more reviewed finding on this topic
    • Published — County building and planning permit fees published through the county Master Fee Schedule.
      “Applications and Forms [...] Master Fee Schedule”
  • Permit processPartial

    County building and land-use permit processes.

    • Building applications can be submitted through the CloudPermit portal.
    • Submittals must include the applicable application, site plan, complete construction drawings, design criteria, and Master Fee Schedule.
    • Incomplete construction drawings could result in denial of the application submittal.
    • Town-area applications require prior town-administration approval.
    “The Building Department permit submittal process requires all permit submittals to be complete for acceptance.”
    One more reviewed finding on this topic
    • Published (with conditions) — County building-permit applications for unincorporated Adams County and specified towns.
      “The Building Department permit submittal process requires all permit submittals to be complete for acceptance. Before submitting make sure your permit submittal includes.”

Washington rules that apply here

  • Owner-builder exemptionConditional

    An owner or other person performing construction-related contractor activities on the person's own property or personal residence under Washington contractor-registration law.

    • The exemption concerns registration provisions under chapter 18.27 RCW and does not itself eliminate applicable building, electrical, plumbing, mechanical, land-use, or inspection requirements.
    • For work on the person's own property, the exemption does not apply when the person performs contractor activities for the purpose of selling, demolishing, or leasing the property.
    • For an owner contracting with a registered contractor, the exemption does not apply to a person performing contractor activities to lease or sell improved property owned for less than twelve months.

    small-project contract threshold: < 500 USD (The threshold exemption does not apply when the work is part of a larger operation, contracts are divided to evade the chapter, or the person advertises as a contractor.)

    “The registration provisions of this chapter do not apply to: [...] (12) Any person working on his or her own property, whether occupied by him or her or not, and any person working on his or her personal residence, whether owned by him or her or not but this exemption shall not apply to any person who performs the activities of a contractor on his or her own property for the purpose of selling, demolishing, or leasing the property;”
    2 more reviewed findings on this topic
    • Available (with conditions) — Washington contractor-registration exemption for persons working on their own property or personal residence, including Adams County.
      “Any person working on his or her own property, whether occupied by him or her or not, and any person working on his or her personal residence, whether owned by him or her or not but this exemption shall not apply to any person who performs the activities of a contractor on his or her own property for the purpose of selling, demolishing, or leasing the property;”
    • Conditional — Washington contractor-registration requirements for a person working on the person’s own property or personal residence.
      “Any person working on his or her own property, whether occupied by him or her or not, and any person working on his or her personal residence, whether owned by him or her or not but this exemption shall not apply to any person who performs the activities of a contractor on his or her own property for the purpose of selling, demolishing, or leasing the property;”
  • Building heightSpecified

    Buildings subject to Washington's state building code, with allowable height determined by occupancy classification and type of construction.

    • Table 504.3 is occupancy- and construction-type-specific.
    • The source states that Chapters 4 and 5 contain specific exceptions to the allowable height.
    • The table includes NS and UL entries; the source footnotes state that NS is only for evaluation of existing building height under the International Existing Building Code and that other entries have sprinkler-related conditions.

    allowable building height: occupancy-classification and construction-type specific values in Table 504.3 feet above grade plane (See Chapters 4 and 5 for specific exceptions.)

    “Allowable Building Height in Feet Above Grade Plane”
  • Septic inspectionRequired

    On-site sewage systems for all activities requiring an OSS permit statewide.

    • The local health officer or an authorized inspector must coordinate access before inspection.
    • If the owner does not authorize access, the local health officer may use administrative search-warrant procedures under RCW 70A.105.030.
    • For a single-property OSS serving one dwelling unit on that property, an inspection and maintenance easement may not be required as a permit condition.
    • During final construction inspection, the local health officer or OSS designer must confirm the OSS meets the approved design.
    • Required inspections must include the minimum tank, lid/access/riser, OSS/reserve-area, component, record-drawing, and proprietary-product review items stated in WAC 246-272A-0260(5).
    “(1) For all activities requiring a permit, the local health officer shall inspect the OSS.”
    One more reviewed finding on this topic
    • Required — On-site sewage-system activities requiring a permit in Adams County.
      “For all activities requiring a permit, the local health officer shall inspect the OSS.”
  • Well permitLimited

    Groundwater wells and groundwater uses statewide under Washington's water-right permit exemption.

    • Domestic use is exempt up to 5,000 gallons per day.
    • Industrial use is exempt up to 5,000 gallons per day.
    • Lawn or garden irrigation is exempt only for a half-acre or less.
    • Stockwater is exempt.
    • Only one permit-exempt use of each type is allowed for any one project, regardless of project size.
    • Withdrawals from multiple wells for one project are aggregated toward the exemption limits.
    • Local governments and other laws and rules may impose additional requirements and limits.
    • Use in excess of the listed amounts, use for other purposes, or use from a surface-water source requires applying for and receiving a water-right permit.
    • Before drilling, a notice of intent must be submitted to Ecology 72 hours before drilling starts; the NOI is not itself a permit or approval to use water.
    • Permit-exempt uses remain subject to state water law, including possible restrictions relating to senior water rights and Streamflow Restoration Act requirements.

    domestic groundwater use exemption: <= 5000 gallons per day (Per project, with withdrawals from multiple wells aggregated.) · industrial groundwater use exemption: <= 5000 gallons per day (Per project, with withdrawals from multiple wells aggregated.) · lawn or garden irrigation exemption: <= 0.5 acre (For lawn or garden irrigation.) · well construction notice: 72 hours before drilling (Notice of intent is not a permit, certificate, or water-right application.)

    “The groundwater permit exemption allows for four small uses of groundwater without a water right permit: Domestic uses of up to 5,000 gallons per day Industrial uses of up to 5,000 gallons per day Irrigation of a lawn or garden, a half-acre or less in size Stockwater”
  • Agricultural exemptionAvailable (with conditions)

    Temporary growing structures used solely for production of horticultural plants in Washington.

    • The exemption is limited to temporary growing structures.
    • The structures must be used solely for production of horticultural plants, including ornamental plants, flowers, vegetables, and fruits.
    • The statute states that a temporary growing structure is not considered a building or structure for purposes of chapter 19.27 RCW.
    • This is not a general exemption for residences or all agricultural buildings.
    “The provisions of this chapter do not apply to temporary growing structures used solely for the production of horticultural plants including ornamental plants, flowers, vegetables, and fruits. A temporary growing structure is not considered a building or structure for purposes of this chapter.”
  • Campground & park staysLimited

    Recreational vehicles in the context of Washington's manufactured/mobile-home community statutes

    • The rule defines an RV as temporary and transient living quarters.
    • The RV is not occupied as a primary residence.
    • The RV is not immobilized or permanently affixed to a manufactured/mobile home lot.
    • This claim does not establish general statewide siting permission on private land; local land-use and building rules may apply.
    “(12) "Recreational vehicle" means a travel trailer, motor home, truck camper, or camping trailer that is primarily designed and used as temporary living quarters, is either self-propelled or mounted on or drawn by another vehicle, is transient, is not occupied as a primary residence, and is not immobilized or permanently affixed to a manufactured/mobile home lot.”
    One more reviewed finding on this topic
    • Limited — Camping and temporary occupancy in Washington State Parks facilities
      “The maximum length of stay shall be no more than 10 nights in one park within a 30-day period. Total nights stayed by the same camping party must not exceed 90 nights per calendar year in all state parks. These limitations shall not apply to those individuals who meet the qualifications of WAC 352-32-280 and 352-32-285.”
  • county zoning authorityGeneral

    Washington counties adopting zoning and related official controls for county jurisdiction, including unincorporated areas.

    • A county must create a planning agency as authorized in RCW 36.70.030 and RCW 36.70.040 before engaging in the chapter's planning program.
    • Zoning maps may be adopted only for areas covered by a comprehensive plan containing at least a land use element and a circulation element.
    • Zoning regulations may address land uses, building location and dimensions, yards and open spaces, population density, lot coverage, parking, and minimum gross floor area requirements for single-family detached dwellings.
    • The cited enabling provisions do not state a population threshold, named-county limitation, or special geographic limitation.
    “Any board, by ordinance, may establish classifications, within each of which, specific controls are identified, and which will regulate:”
    One more reviewed finding on this topic
    • General — Washington counties may plan and adopt zoning and other official controls for county land, including unincorporated areas, through their boards and planning agencies.
      “Such official controls may include, but are not limited to, ordinances establishing zoning, subdivision control, platting, and adoption of detailed maps.”
  • county building authorityGeneral

    Washington counties requiring and enforcing building permits and adopting amendments to the state building code for residential construction within county jurisdiction, including unincorporated areas.

    • The state building code must be enforced by counties and cities within their jurisdictional boundaries.
    • A county without a building department must contract with another county, city, or approved inspection agency for enforcement.
    • County amendments may not diminish the minimum performance standards and objectives of the state building code.
    • Residential-building amendments are subject to approval by the state building code council under RCW 19.27.074(1)(b), except as provided by statute.
    • The building-permit definition incorporates exemptions in International Building Code section 105.2 and International Residential Code section R105.2.
    • Counties may adopt permit exemptions for certain specified R-3 or M-1 construction or alteration with total fair market value not exceeding $1,500, but the exemption does not remove substantive code standards.

    permit-exemption fair-market-value ceiling: <= 1500 USD (Applies only to certain construction or alteration of group R, division 3, or group M, division 1 occupancies under RCW 19.27.060(7); substantive code standards still apply.)

    “The state building code required by this chapter shall be enforced by the counties and cities. Any county or city not having a building department shall contract with another county, city, or inspection agency approved by the county or city for enforcement of the state building code within its jurisdictional boundaries.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Certificate of occupancy — Certificate-of-occupancy requirements in Adams County.
  • Lot coverage — Lot-coverage standards under Adams County Code Titles 16–18.
  • Camping on your land — Temporary camping outside specifically regulated recreational-vehicle parks in Adams County.

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Water rights & wells in Adams County

Whether a new home can legally get its own water here — the sub-state groundwater regime, from Washington’s water agency.

Over-appropriated / declining

The aquifer here is over-appropriated and declining. A domestic well is usually still permit-exempt, but long-term supply is a genuine risk.

Household wellExempt up to a limit

RCW 90.44.050 exempts up to 5,000 gpd for domestic use, but the 2018 Streamflow Restoration Act caps NEW permit-exempt domestic wells at 3,000 gpd/connection in some basins and 950 gpd (350 gpd indoor in drought) in others, and new post-2020 wells in the adjudicating Nooksack basin are limited to ~500 gpd indoor.

Limit: 5,000 gpd base (RCW 90.44.050); capped to 3,000 or 950 gpd/connection in streamflow-restoration basins; ~500 gpd indoor for new Nooksack wells

Washington Dept of Ecology — Groundwater permit exemption ↗
  • Odessa Subarea (deep basalt aquifer decline)partial of county

    Columbia Basin deep basalt aquifer severely depleted (some wells ~2,400 ft, hot/high-sodium); Ecology's response is a Columbia River surface-water replacement program rather than a formal closure, but new large groundwater supply is practically unavailable.

    WA Dept of Ecology ↗

Hybrid state (appropriation + riparian). Groundwater rules change and basin boundaries follow the aquifer, not the county line — confirm current well and appropriation rules with the Washington state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in Adams County, Washington

Is Adams County a good place to live off-grid or homestead?

Adams County scores 40/100 on the Bolthole Index, a marginal county profile. Its strengths: manageable long-term carry cost and mixed durability signals. Watch-outs: weak self-sufficiency basics: only 11.5″ of rain a year and more administrative friction around building and land use.

Do you need a building permit in Adams County, Washington?

Adams County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Adams County Health Department — Environmental Health. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

Can you live in an RV or tiny home on your land in Adams County?

Living in an RV on your own land in Adams County is limited to specific cases: Occupancy of recreational vehicles in Adams County recreational-vehicle parks. RV parks are intended for visitors residing in an RV for no more than 180 days out of the year. The minimum RV-park size is two acres. A tiny home is allowed. Confirm with the county before relying on it.

How much does land cost in Adams County, Washington?

Land in Adams County runs about $2,133 per acre, based on the latest county data.

What is the water situation in Adams County?

Adams County gets about 11.5" of rain a year, with severe drought in roughly 13.6% of years. On water rights, Adams County lies in the Odessa Subarea (deep basalt aquifer decline) — Columbia Basin deep basalt aquifer severely depleted (some wells ~2,400 ft, hot/high-sodium); Ecology's response is a Columbia River surface-water replacement program rather than a formal closure, but new large groundwater supply is practically unavailable..

How remote is Adams County?

A representative private-land location has about 15,347 people within a 30-minute drive and 1,614,770 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

How Adams compares in Washington

Compare side-by-side →See all 39 Washington counties ranked →