Zoning, building permits and septic rules in Sequim, Washington

Sequim’s own rules

• Building permitRequired

  New commercial construction, tenant improvements, and alterations to existing structures inside Sequim city limits.

  • Residential work has enumerated permit exemptions in SMC § 15.04.021.

  “Permits are required for new construction, tenant improvements”

• Building code adoptedAdopted (with conditions)

  Residential construction inside Sequim city limits.

  • The City adopts the state-adopted IRC by reference but excludes IRC Chapters 11 and 25 through 43.
  • Appendix Q, Tiny Houses, is included in the City's IRC adoption.

  “The International Residential Code, as published by the International Code Council, and as adopted by the state of Washington, is hereby adopted by reference with the following additions, deletions, and exceptions; provided, that Chapters 11 and 25 through 43 of this IRC code are not adopted.”

• Certificate of occupancyLimited

  Existing buildings or portions of buildings proposed for use or occupancy inside Sequim city limits.

  • Exceptions include specified continuously maintained pre-code buildings, previously certificated occupancies, all R-3 or U occupancies, and individual dwelling units with R-1 or R-2 occupancies.
  • A certificate is issued after approval of required inspections and completion of the permit scope.

  “All buildings must receive a Certificate of Occupancy before any use or occupancy is authorized in any existing building or portion of the building, unless: 1. The building existed before the City of Sequim first adopted the Uniform Building Code and the original use or occupancy has been continuously maintained; 2. The building or portion thereof previously obtained a Certificate of Occupancy and occupancy historically and currently complies with the permit and Certificate of Occupancy; 3. All R-3 or U occupancies; or 4. Individual dwelling units with R-1 or R-2 occupancies.”

• Local zoningPresent (with conditions)

  Land inside Sequim city limits.

  • Uses and structures must comply with the applicable zoning district and permits required by law and city ordinances.

  zoning district classes: 20

  “For the purposes of this title and to carry out these regulations, the city of Sequim hereby designates 20 classes of districts, and the specifically permitted and conditional uses described and tabulated in Chapter 18.20 SMC.”

• Zoning districtsPublished (with conditions)

  Land inside Sequim city limits.

  • The official zoning map and amendments are available for public inspection in the department of community and economic development offices.

  district classes: 20

  “For the purposes of this title and to carry out these regulations, the city of Sequim hereby designates 20 classes of districts, and the specifically permitted and conditional uses described and tabulated in Chapter 18.20 SMC.”

• Accessory dwellingsAllowed (with conditions)

  Lots in zoning districts where single-family residential uses are allowed inside Sequim city limits.

  • A maximum of two ADUs is allowed in addition to one principal dwelling.
  • The lot must meet the minimum size for the principal unit and all other applicable Chapter 18.21 criteria.
  • ADUs may be attached, detached, or conversions of existing structures.

  maximum ADUs per lot: <= 2 ADUs (In addition to one principal dwelling unit.)

  “a maximum of two accessory dwelling units are allowed per lot”

• Mandatory utility hookupSewer (with conditions)

  Lands, premises, and habitable structures inside Sequim city limits with an accessible sanitary sewer.

  • The rule is subject to SMC §§ 13.40.030 and 13.102.040.
  • The city engineer determines accessibility.
  • The sewer must be within 200 feet measured along a public place or sewer easement.
  • Storm drainage must be managed under Chapter 13.104 and may not enter the sanitary sewer.

  sewer availability distance: <= 200 feet (Measured from the closest point of the building site or premises along a public place or sewer easement.)

  “whenever such a sewer is located within 200 feet”

• Permit feesPublished (with conditions)

  Building permits, plan reviews, inspections, and expired permits inside Sequim city limits.

  • Fees are provided in and amended by the City and are subject to exceptions for affordable/workforce housing.
  • The cited section directs users to Chapter 3.68, Rates and Fees.

  “Fees for building permits, plan reviews, and inspections”

Rules another office applies inside Sequim

Sequim does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

• Minimum lot sizeSpecified

  Detached residences in Sequim's R4-8 residential zone.

  • The R4-8 table also specifies a 14,500-square-foot maximum lot size and applies site-plan review under Chapter 18.22.

  minimum lot size: >= 5400 square feet (Detached residences in R4-8.)

  “Residences (Detached) | Min. lot size – 5,400 sf Max. lot size – 14,500 sf* | 25', except 18' in central height district (see Notes below) | 15' | Side: 6' each side; or 12' one side only if zero-lot-line development Rear: 15' | 40% lots 10,000 sf and larger; increases by 0.4% for each 100 sf lot area less than 10,000 sf | 2 spaces/residence | Site plan review per Chapter 18.22 SMC”

• Lot coverageSpecified

  Detached residences in Sequim's R4-8 residential zone.

  • For lots smaller than 10,000 square feet, coverage increases by 0.4 percent per 100 square feet of lot area below 10,000 square feet.

  maximum lot coverage: <= 40 percent (Lots 10,000 square feet and larger in R4-8.)

  “Residences (Detached) | Min. lot size – 5,400 sf Max. lot size – 14,500 sf* | 25', except 18' in central height district (see Notes below) | 15' | Side: 6' each side; or 12' one side only if zero-lot-line development Rear: 15' | 40% lots 10,000 sf and larger; increases by 0.4% for each 100 sf lot area less than 10,000 sf | 2 spaces/residence | Site plan review per Chapter 18.22 SMC”

• Building heightSpecified

  Detached residences in Sequim's R4-8 residential zone.

  • The height limit is 18 feet in the central height district under the table's stated exception.

  maximum height: <= 25 feet (18 feet in the central height district.)

  “Residences (Detached) | Min. lot size – 5,400 sf Max. lot size – 14,500 sf* | 25', except 18' in central height district (see Notes below) | 15' | Side: 6' each side; or 12' one side only if zero-lot-line development Rear: 15' | 40% lots 10,000 sf and larger; increases by 0.4% for each 100 sf lot area less than 10,000 sf | 2 spaces/residence | Site plan review per Chapter 18.22 SMC”

Still unanswered

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

• Owner-builder exemption — Owner-built residential construction inside Sequim city limits.
• Minimum dwelling size — Detached residences in Sequim's R4-8 residential zone.
• Living in an RV — Residential occupancy of an RV on private land inside Sequim city limits.
• Camping on your land — Temporary camping on private land inside Sequim city limits.
• Who permits septic — On-site sewage systems inside Sequim city limits.

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.

Off-grid gear

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

• Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
• Power Bluetti Solar generators and home battery backup for living off the grid.
• Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
• Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.

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