Bolthole Index

Benton County, Washington

Zoning, building permits and septic rules in Kennewick, Washington

The City of Kennewick, Washington adopts its own zoning code, Title 18 of the municipal code1, and a new single-family home inside city limits needs a residential building permit from the city2. Septic permits for on-site systems come from the Benton-Franklin Health District, not the city3. Benton County's rules cover only unincorporated land4.

At a glance

Zoning
City of Kennewick, Title 18 of the municipal code1
Building permit
Required from the city for a new single-family home, remodel or addition2
Minimum lot, RS zone
8,000 sq ft5
RS setbacks
15 ft front, 20 ft garage, 5 ft side, 15 ft rear6
Accessory dwellings
Allowed in residential zones, up to two per lot7
Septic
Benton-Franklin Health District permits on-site systems3
RV and tiny-home living
Not confirmed; ask Community Planning8

Who to call

Building permits

City of Kennewick Building Safety Division

Building permits, plan review and inspections inside Kennewick city limits

509-585-4561

210 W 6th Avenue, Kennewick, WA 99336

Building permits

City of Kennewick permitting guide, Step 6 (residential building permits)

Step-by-step residential building permit process, applications and forms

509-585-4450

210 W 6th Ave, Kennewick, WA 99336

Zoning

City of Kennewick Community Planning Department

Zoning questions, the zoning map and permitted uses by zone inside Kennewick

(509) 585-4280

210 W 6th Ave, Kennewick, WA 99336

Septic permits

Benton-Franklin Health District On-Site Sewage Program

Permits, design oversight and inspections for on-site septic systems in Benton and Franklin counties

509.460.4200

7102 W. Okanogan Place Kennewick, WA 99336

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

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

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Does Kennewick have zoning, and what does it mean for lot size and setbacks?

Yes. The City of Kennewick administers its own zoning code, Title 18 of the Kennewick Municipal Code, and the city's zoning page sends residents to chapter 18.12 for permitted uses by zone1. The residential districts are RMH, RS, RL, RM, RH, RTP and UMU, and the city's zoning map application shows the designation for any parcel98.

Rules differ by district, so check yours first. In RS, the main single-family district, the minimum lot is 8,000 sq ft5, with a 15 ft front setback, a 20 ft garage setback, a 5 ft side setback and a 15 ft rear setback6. Buildings in RS top out at 35 ft or 2.5 stories, whichever is less10. In RL, the minimum lot is 5,500 sq ft11 with the same setbacks12 and the same height limit13. Table footnotes may modify these figures, so confirm with Community Planning at (509) 585-42808.

Do you need a building permit in Kennewick, and who issues it?

Yes. Anyone building a new single-family residence, a remodel or addition, or a miscellaneous residential project inside Kennewick needs a residential building permit from the City of Kennewick2. Benton County's building division covers only unincorporated land, so city addresses do not go to the county counter4.

The city offers two routes. Express permitting returns permits in 2-3 business days and adds a 20% convenience fee, while over-the-counter permitting usually takes up to 15 business days with no convenience fee2. Permitted work is inspected, and a certificate of occupancy comes after all required inspections pass14. Contact the Building Safety Division at 509-585-456115. We could not confirm which building code edition the city has adopted or its fee schedule; ask the Building Safety Division.

Can you build an accessory dwelling or tiny home in Kennewick?

Accessory dwelling units are allowed in Kennewick's residential zones, subject to staff review7. A lot can hold two ADUs, as one attached and one detached, two attached, or two detached. A detached ADU is limited to 24 ft in height, and an ADU's gross floor area may not exceed 1,100 sq ft7. The lot must meet the minimum lot size for its zone7.

We could not confirm whether Kennewick allows living in an RV, camping on private land, or a tiny home on wheels inside city limits. Ask Community Planning at (509) 585-4280 before you buy or park anything on a lot8.

How do septic permits work inside Kennewick?

The Benton-Franklin Health District, not the city, permits, oversees the design and installation of, and inspects on-site septic systems with flows under 3,500 gallons per day in Benton County16. A permit from the district is required before anyone installs, alters or repairs an on-site system17.

We could not confirm whether a given lot inside Kennewick must connect to city sewer or may use a septic system. Ask the Benton-Franklin Health District at 509.460.420018 and the city's Building Safety Division at 509-585-456115 before relying on a septic system inside city limits. Wells and private water supplies are also unconfirmed for city lots.

Building a home in Kennewick: the steps, in order

  1. Find your zone on the city's zoning map and read the residential use table in Title 181.
  2. Check lot size, setbacks and height for your district56.
  3. Ask the Benton-Franklin Health District whether your lot may use septic or must use sewer18.
  4. Choose express or over-the-counter permitting and assemble the application2.
  5. Submit to the city, answer any deficiency notes, then pay and receive the permit2.
  6. Schedule the required inspections and print the certificate of occupancy once all pass14.

What stays with Benton County, and what to check before you buy

Land outside Kennewick city limits falls under Benton County, where the county's own planning and building divisions apply4. Septic permits for every Benton County address come from the Benton-Franklin Health District3.

These figures describe Benton County, not Kennewick alone: the typical home value is about $452,29019, the effective property tax rate is 0.8%20, and the median property tax bill is $2,910 a year21. Before you buy, confirm the parcel's zoning, whether it lies in a mapped floodplain, and the utility connections available at the lot.

Watch-outs

  • Table footnotes in Kennewick's residential standards may modify the lot-size and setback figures, so confirm your district's numbers with Community Planning at (509) 585-42808.
  • We could not confirm Kennewick's adopted building code, permit fees, RV or tiny-home occupancy, or sewer-connection rules; ask the Building Safety Division at 509-585-456115.
  • Benton County's building and planning counters serve unincorporated land only, not Kennewick addresses4.

Sources

  1. What is Zoning? - City of Kennewick (Kennewick), quoted and re-checked
  2. City of Kennewick permitting guide, Step 6 (residential building permits) (go2kennewick.com)
  3. On-site Sewage Construction Permit Application, quoted and re-checked
  4. Public Works FAQs, quoted and re-checked
  5. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  6. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  7. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  8. City of Kennewick Community Planning Department (go2kennewick.com)
  9. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  10. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  11. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  12. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  13. Kennewick Municipal Code Title 18 Chapter 18.12 Zone Districts and Standards (Municode) (Kennewick), quoted and re-checked
  14. Step 6 - Permitting 6.6 Occupancy - City of Kennewick (Kennewick), quoted and re-checked
  15. City of Kennewick Building Safety Division (go2kennewick.com)
  16. On-Site Sewage, quoted and re-checked
  17. On-site Sewage Construction Permit Application, quoted and re-checked
  18. Benton-Franklin Health District On-Site Sewage Program (bfhd.wa.gov)
  19. Typical home value (Zillow): Bolthole Index county data
  20. Effective property tax rate: Bolthole Index county data
  21. Median property tax bill: Bolthole Index county data

Written October 24, 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.

Answers from the rulebook for Kennewick

Kennewick’s own rules

  • InspectionsRequired

    Permitted construction inside Kennewick city limits, per the city's Step 6 permitting guide.

    • The city's occupancy step refers to 'all required inspections', so inspections are part of the permitting process.
    • Inspection types and schedule are not stated on the page read; they are in step 6.5 Inspections, not yet opened.
    “once all required inspections have been completed and approved, you can print a certificate of occupancy.”
  • Local zoningPresent

    Land inside Kennewick city limits; Kennewick city adopts and administers its own zoning code (Title 18).

    • Zoning-only topics for Kennewick are answered from Title 18 of the Kennewick Municipal Code, not from county zoning.
    • The city's zoning page directs residents to Title 18 chapter 18.12 for permitted uses by zone.
    “title 18 of the kennewick municipal code is the city's " zoning code."”
  • Zoning districtsPublished

    Zone districts within Kennewick city limits.

    • Zone abbreviations listed in the residential use table include RMH, RS, RL, RM, RH, RTP and UMU; the table also lists non-residential zones.
    • The city's zoning map application identifies each parcel's zoning designation per the city's zoning page.
    “residential use table rmh rs rl rm rh rtp umu cn co cbd cc cr car cg cm hmu bp ip il ih jf pf os”
  • Minimum lot sizeSpecified

    RS zone district in Kennewick city (main single-family residential district, column RS of KMC 18.12.010 a.2 residential site development standards table).

    • Minimum lot size 8,000 sf for RS per the residential standards table.
    • Table footnotes 5, 8 and 9 apply to the RS column; their text was not read in full and may modify this figure.
    • Townhouse lots in RS have a separate minimum lot size of 1,800 sf per the same table row 'min. lot size (townhouse)'.
    • The Municode text carries 2025 amendment history (ord. 25-6110, 2025); the page states no effective date for this table row.

    minimum lot size: >= 8000 sq ft (townhouse lots: 1,800 sf per table)

    “rs 5,8,9 rl 5,8,9 rm 3, 4, 5, 6,8,9 rh 3, 4, 5, 6,8,9 rtp 3, 4, 5 rmh 6,8,9 umu 3, 7 max. density 1 n/a n/a n/a n/a n/a n/a n/a unit density 1a 6 6 6 6 n/a 6 n/a min. lot size 8,000 sf 5,500 sf 4,000 sf 3,500 sf 1 acre 5,500 sf n/a”
    One more reviewed finding on this topic
    • Specified — RL zone district (residential, low density) in Kennewick city, column RL of KMC 18.12.010 a.2 residential site development standards table; the closest rural-residential-type district in the code.
      “min. lot size 8,000 sf 5,500 sf 4,000 sf 3,500 sf 1 acre 5,500 sf n/a min. lot size (townhouse) 1,800 sf 1,800 sf 1,800 sf 1,600 sf n/a 1,800 sf n/a min. lot width 2 50' 45' 35' n/a n/a 45' n/a”
  • SetbacksSpecified

    RS zone district in Kennewick city (main single-family residential district).

    • Minimum front yard/street setback 15 ft for RS per the table.
    • Minimum garage setback 20 ft for RS.
    • Minimum side yard setback 5 ft and rear yard setback 15 ft for RS.
    • Table footnote 2 applies to the setback rows; its text was not read in full.
    • Detached accessory structures are subject to KMC 18.27.030 setbacks, except for maximum height, per the ADU standards.

    front yard/street setback: 15 ft · garage setback: 20 ft · side yard setback: 5 ft · rear yard setback: 15 ft

    “min. front yard/ street setback 2 15' 15' 15' 15' 15' 15' see kmc 18.80 min. garage setback 2 20' 20' 20' 20' 20' 20' n/a min. side yard setback 2 5' 5' 5' 5' 5' 5' 0' min. rear yard setback 2 15' 15' 15' 15' 15' 15' 5'”
    One more reviewed finding on this topic
  • Building heightSpecified

    RL zone district (residential, low density) in Kennewick city.

    • Maximum height 35 ft or 2.5 stories, whichever is less, for RL per the table.
    • Table footnotes for the RL column (5, 8, 9) were not read in full.

    maximum building height: <= 35 ft (or 2.5 stories, whichever is less)

    “max. height 35' or 2.5 stories, whichever is less 35' or 2.5 stories, whichever is less 35' 45' n/a 35' or 2.5 stories, whichever is less n/a”
    One more reviewed finding on this topic
  • Accessory dwellingsAllowed

    Accessory dwelling units on residential lots in Kennewick city residential zones.

    • Residential use table lists accessory dwelling units under staff review (review process I) in the residential zones.
    • Up to two ADUs per lot in the configurations listed: one attached and one detached, two attached, or two detached.
    • ADUs are permitted on lots meeting the minimum lot size for the zone.
    • Detached ADU maximum height is 24 ft; attached ADU maximum height is the zone's primary-unit height.
    • Total gross floor area of an ADU shall not exceed 1,100 square feet; garages and unheated storage are excluded from living area.

    maximum ADU gross floor area: <= 1100 sq ft (garages and unheated storage areas excluded from living area) · maximum detached ADU height: <= 24 ft (attached ADU follows zone height)

    “accessory dwelling units shall be permitted in all residential zoning districts, shall adhere the appearance of single-family residences and be subject to the following development standards: (1) number of accessory dwelling units permitted: two accessory dwelling units shall be permitted in all residential zoning districts in the following configurations:”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Kennewick or Benton County directly.

  • Building permit — New residential construction inside Kennewick city limits.
  • Owner-builder exemption — Owner-builder construction in Kennewick city.
  • Building code adopted — Building code adopted by Kennewick city.
  • Minimum dwelling size — Minimum dwelling size inside Kennewick city limits.
  • Lot coverage — Maximum lot coverage in Kennewick residential zones.
16 more unanswered
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Subdividing land
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees

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.

Unanswered questions are usually a sign that Kennewick publishes no rule on the point, not that none exists. Benton County’s page lists the county offices to call.

← All of Benton County: county rules, score and offices