Zoning, building permits and septic rules in Yelm, Washington

Yelm’s own rules

• Building permitRequired

  Buildings and structures in Yelm city subject to the adopted building code.

  • The code provides for issuance of permits and collection of fees; the specific permit exceptions were not resolved in this research pass.

  “When Required. Construction permits are required pursuant to the International Residential Code, International Building Code, International Plumbing Code, International Mechanical Code, and Washington State Energy Code, as adopted by Washington State and the city of Yelm.”

• Building code adoptedAdopted (with conditions)

  Buildings and structures in Yelm city.

  • The adopted International Building Code and International Residential Code are amended by WAC Chapters 51-50 and 51-51 and include Appendix Q, Tiny homes.

  “Those certain documents, one copy of which is on file and is open for inspection of the public in the office of the city clerk/treasurer, being marked and designated as: "International Building Code" and "International Residential Code," published by the International Code Council and amended by Chapters 51-50 and 51-51 WAC, including Appendix Q, Tiny homes, referenced herein; are adopted as the code of the city for regulating the erection, construction, enlargement, alteration, repair, moving, removal, demolition, conversion, occupancy, equipment, use, height, area and maintenance of all buildings or structures in the city; providing for issuance of permits and collection of fees.”

• Local zoningPresent (with conditions)

  Land inside Yelm city limits.

  • The municipal code contains Title 18, Unified Development Code, including a Division 5 Zoning.

  “Zoning Map. The zoning districts are bounded as shown on the official zoning map of the city of Yelm as adopted as part of the city of Yelm comprehensive plan.”

• Zoning districtsPublished (with conditions)

  Land inside Yelm city limits.

  • The published Unified Development Code lists residential, commercial, industrial, open-space/institutional, and other zoning chapters.

  “To carry out the purpose of this title, the city is divided into the following districts: low-density residential (R-4), moderate-density residential (R-6), high-density residential (R-16), central business district (CBD), commercial (C-1), heavy commercial (C-2), large lot commercial (C-3), industrial (I) and open space/institutional (OS).”

• Minimum lot sizeNone (with conditions)

  Lots in Yelm's R-4 low-density residential district.

  • The R-4 district otherwise regulates allowed density and development standards.

  “Minimum Lot Area. There is no minimum lot area.”

• Manufactured homesLimited

  Manufactured homes used as temporary construction offices or security-personnel living quarters inside Yelm city limits.

  • Use must be part of a construction project; it is limited to construction-personnel office use or security-personnel temporary living quarters; it may extend no more than 90 days after construction completion. A 30-day extension may be granted by the public services department upon written request when reasonable and in the public interest; off-street parking must be provided for construction staff.

  period beyond completion of construction: <= 90 days (A 30-day extension may be granted under the stated conditions.)

  “Manufactured home as part of a construction project for office use of construction personnel or temporary living quarters for security personnel for a period extending not more than 90 days beyond completion of construction. A 30-day extension may be granted by the public services department upon written request of the developer and upon the department's finding that such request for extension is reasonable and in the public interest. Off-street parking shall be provided for construction staff.”

• Accessory dwellingsAllowed (with conditions)

  Secondary dwelling units on single-family lots in Yelm's R-4 low-density residential district.

  • The district's uses are subject to project approvals and Unified Development Code design standards. One secondary dwelling unit may be created on a single-family lot. On lots of record under one acre, conversion or addition may not exceed 1,000 square feet; on lots of record of one acre or more, it may not exceed 1,500 square feet.

  secondary dwelling units per single-family lot: 1 · maximum conversion or addition size: <= 1000 square feet (Lots of record under one acre.) · maximum conversion or addition size: <= 1500 square feet (Lots of record of one acre or more.)

  “Secondary Dwelling Units. One secondary dwelling unit may be created on a single-family lot.”

• Subdividing landRegulated (with conditions)

  Subdivisions inside Yelm city limits involving 25 or more housing units or covered commercial or industrial development.

  • Every subdivision or combination of subdivisions of 25 or more housing units must provide more than one vehicular access from an arterial or collector street. Residential subdivision lots adjacent to arterial and collector streets may not have direct access, except on a public works director's written finding satisfying all enumerated standards.

  housing units triggering more than one vehicular access: >= 25 housing units

  “Every subdivision or combination of subdivisions of 25 or more housing units, and any commercial or industrial development calculated to generate more than 250 vehicle trips per day, shall provide more than one vehicular access from an arterial or collector street.”

• Permit processPartial

  Uses in Yelm's R-4 low-density residential district.

  • Allowed uses are subject to project approvals and Unified Development Code design standards; this is not a complete citywide permit-process description.

  “The following uses are allowed within the low-density residential zoning district, subject to the project approvals and design standards of the Unified Development Code:”

Still unanswered

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

• Owner-builder exemption — Owner-builders inside Yelm city limits.
• Inspections — Building work inside Yelm city limits.
• Certificate of occupancy — Buildings in Yelm city.
• Minimum dwelling size — Dwellings in Yelm's R-4 low-density residential district.
• Lot coverage — Development in Yelm's R-4 low-density residential district.

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 Yelm 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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