Bolthole Index

Washington County, Oregon

Zoning, building permits and septic rules in Tigard, Oregon

Inside Tigard city limits, the City of Tigard adopts its own development code and building code, and its Permit Center takes building permit applications123. Zoning approval comes from the city's Planning Division, not Washington County4. Septic permits for homes not on public sewer come from Washington County Environmental Health5.

At a glance

Building permits
City of Tigard Permit Center; Oregon requires permits for new construction36
Zoning
City of Tigard Development Code, with residential zones RES-A through RES-E7
Septic
Washington County Environmental Health, for homes not on public sewer5
Accessory dwellings
One detached ADU per lot on small form residential lots, up to 800 sq ft8
RV and tiny-home living
Not confirmed; ask Tigard Planning9
Owner-builder
Oregon allows owner-built homes with limited structural-code exemptions; Tigard's own rule not confirmed10

Who to call

Building permits

City of Tigard Permit Center (Building)

Building permit applications and building inspections inside Tigard city limits

503-718-2439

[email protected]

13125 SW Hall Blvd, Tigard, OR 97223

Planning & zoning

City of Tigard Planning Division

Land use applications and zoning questions inside Tigard city limits

503-718-2421

[email protected]

13125 SW Hall Blvd, Tigard, OR 97223

Septic permits

Washington County Environmental Health (Onsite Sewage Program)

Septic system permits, site evaluations and inspections for properties not on public sewer

503-846-8722

[email protected]

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 Tigard means bringing your own water and power. The kit we’d start with:

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Does Tigard, Oregon have zoning, and what does it allow?

Yes. Land inside Tigard city limits is zoned under the City of Tigard Development Code, and the residential base zones are RES-A, RES-B, RES-C, RES-D and RES-E7. Which zone and plan district applies varies by parcel, so look up the specific lot before you plan anything1.

Tigard allows one detached accessory dwelling unit per lot on small form residential lots, up to 800 square feet and 25 feet high, with at most three dwelling units on the lot8. Mobile homes are handled as mobile home park development, and structures in a mobile home park top out at 25 feet1112.

We could not confirm Tigard's rules on living in an RV, living in a tiny home, minimum dwelling size or lot size; ask the Planning Division9. Washington County's ban on living in an RV applies to unincorporated land, not to Tigard13.

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

Oregon requires permits for all new construction and for structural, plumbing, mechanical and electrical alterations to existing homes6. Inside Tigard, the city has adopted its own building code chapter and takes building permit applications through its Permit Center, not through Washington County Building Services23.

Apply online through the city's Community Development Hub, or call the Permit Center building line at 503-718-24393. Work begun without a required permit triggers an investigation fee equal to the permit fee, charged on top of the permit fee14. Properties in a mapped flood hazard area also need a separate development permit, including for manufactured dwellings and fill15.

We could not confirm which small projects Tigard exempts from permits, so ask the Permit Center before you skip one.

How do septic permits work in Tigard?

Washington County Environmental Health issues septic system permits for households that are not served by public sewer5. The county requires a permit for new onsite systems and for repair or alteration of existing systems, tanks and drainfields16. After the work is done, the installer or permittee must notify the county before the system is covered, and the county then has seven business days to inspect unless it waives inspection17.

A building within a sewer district still needs a sewer connection, even with a composting toilet18. We could not confirm whether Tigard sets any septic rule of its own, so call Environmental Health at 503-846-8722 before you rely on a septic system inside city limits19. Soil matters too: only about 2.2% of Washington County soils rate as not limited for a conventional drain field, so expect a site evaluation20.

Building a home in Tigard: the steps, in order

  1. Look up the parcel's zone and plan district, then confirm the use with the Planning Division at 503-718-242119.
  2. If the lot is not on public sewer, start the septic site evaluation with Washington County Environmental Health5.
  3. Prepare an access plan; Tigard requires one before any land use approval or development permit issues21.
  4. Apply for the building permit through the Community Development Hub3.
  5. Request inspections as work proceeds. Before anyone moves in, a certificate of occupancy is required for a new dwelling, and Tigard does not issue temporary certificates for detached one- and two-family homes2223.

What stays with Washington County, and what to check before you buy in Tigard

Septic permits and well permits are not city matters. Washington County Environmental Health handles septic permits, and Oregon requires a landowner who drills a well to hold a permit and bond unless the landowner is a licensed well constructor524. We could not confirm whether any well can be drilled inside Tigard, so ask the county first.

The county's unincorporated rules, including its rural lot sizes and RV ban, do not apply inside city limits; see the Washington County page for land outside Tigard4.

Before you buy, check the flood hazard map, how the lot connects to a street, and taxes. Washington County's effective property tax rate is 0.9%, with a median bill of $4,852 a year2526.

Watch-outs

  • We could not confirm whether Tigard exempts any small projects from building permits or offers an owner-builder path; Oregon has a statewide owner-builder exemption that covers only ceiling heights, room sizes and temperature levels, and a permit is still issued10.
  • Do not assume Washington County's unincorporated rules apply in Tigard; the city regulates land use and development within its own boundaries4.
  • Tigard's rules on RVs, tiny homes, short-term rentals and agricultural structures are unconfirmed; ask the Planning Division at 503-718-2421 before you buy9.

Sources

  1. City of Tigard, OR Code of Ordinances (Tigard), quoted and re-checked
  2. Tigard Code, Chapter 14.04 Building Code (Tigard), quoted and re-checked
  3. City of Tigard Permit Center (Building) (tigard-or.gov)
  4. Urban & Rural Land Use Districts, quoted and re-checked
  5. Onsite Sewage, quoted and re-checked
  6. About Oregon residential building permits, quoted and re-checked
  7. Tigard Development Code, Chapter 18.110 Residential Zones (Tigard), quoted and re-checked
  8. Tigard Development Code, Chapter 18.220 Accessory Dwelling Units (Tigard), quoted and re-checked
  9. City of Tigard Planning Division (tigard-or.gov)
  10. 2023 Oregon Residential Specialty Code - ORS 455.320 reprinted (Oregon statewide rule), quoted and re-checked
  11. Tigard Development Code, Chapter 18.260 Mobile Home Parks (Tigard), quoted and re-checked
  12. Tigard Development Code, Chapter 18.260 Mobile Home Parks (Tigard), quoted and re-checked
  13. Can I live in my recreational vehicle (RV)?, quoted and re-checked
  14. Tigard Code, Chapter 14.04 Building Code (Tigard), quoted and re-checked
  15. Tigard Code, Chapter 9.10 Areas of Special Flood Hazard (Tigard), quoted and re-checked
  16. Onsite Sewage Permits, quoted and re-checked
  17. Final Inspection Request and Notice for Onsite Sewage Disposal System Permits, quoted and re-checked
  18. What do I do with the finished material? (Oregon statewide rule), quoted and re-checked
  19. Washington County Environmental Health (Onsite Sewage Program) (washingtoncountyor.gov)
  20. 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
  21. Tigard Development Code, Chapter 18.920 Access, Egress, and Circulation (Tigard), quoted and re-checked
  22. 2023 Oregon Residential Specialty Code, Chapter 1, quoted and re-checked
  23. Tigard Code, Chapter 14.28 Temporary Certificates of Occupancy (Tigard), quoted and re-checked
  24. Landowner Constructed Wells, quoted and re-checked
  25. Effective property tax rate: Bolthole Index county data
  26. 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 Tigard

Tigard’s own rules

  • Building code adoptedAdopted (with conditions)

    Building work inside Tigard city limits regulated by the City building code.

    • The adopted state specialty codes and building requirements are those which Tigard is granted authority to administer.
    • parameters are not a substitute for the individual codes' scoping provisions.
    “Except as otherwise provided in this chapter, the following codes, standards and rules are adopted and shall be in force and effect as part of this municipal code.”
  • InspectionsLimited

    Each mobile home placed in a mobile home park inside Tigard city limits.

    • Applies to mobile homes placed in a mobile home park, not all residential construction.
    • The mobile home must also meet applicable state and federal regulations, be in good repair, and contain the specified plumbing fixtures.
    “Each mobile home placed in a mobile home park must be inspected by the building official and meet the following standards:”
  • Certificate of occupancyLimited

    Temporary full or partial occupancy of a building or structure inside Tigard before issuance of a final certificate of occupancy.

    • A temporary certificate is required only where occupancy is proposed before issuance of a final certificate of occupancy.
    • Temporary certificates may not be issued for detached one- and two-family dwellings and townhouses defined in the Oregon Residential Specialty Code.
    • The approval may be for no more than six months; a replacement application may be submitted no more than 30 days before expiration and full fees apply.

    maximum temporary certificate period: <= 6 months

    “A Temporary Certificate of Occupancy is required to occupy all or any portion of a building or structure if occupancy is proposed prior to the issuance of a Final Certificate of Occupancy.”
  • Local zoningPresent (with conditions)

    Land inside Tigard city limits subject to the City of Tigard Development Code.

    • Applicable residential zones and development standards vary by parcel and plan district.
    “The residential base zones are listed in Table 18.110.1. When this title refers to the residential zones, it is referring to the five base zones listed here.”
  • Zoning districtsPublished (with conditions)

    Tigard residential base zones.

    • The published list in this claim is the five residential base zones; other base and plan districts may apply elsewhere in the city.

    residential base zones: RES-A; RES-B; RES-C; RES-D; RES-E

    “The residential base zones are listed in Table 18.110.1. When this title refers to the residential zones, it is referring to the five base zones listed here.”
  • Building heightSpecified

    Structures in a mobile home park inside Tigard city limits.

    • Applies to all structures in a mobile home park.

    maximum height: <= 25 feet

    “The maximum height of all structures is 25 feet.”
  • Manufactured homesLimited

    Mobile homes in mobile home park developments inside Tigard city limits.

    • The standards apply wherever the mobile-home-park housing type is allowed under the residential and commercial-zone tables, with additional River Terrace Plan District standards.
    • A site development review application is required.
    “The standards of this chapter apply to mobile home park development wherever this housing type is allowed as provided in the use and housing type tables in Chapter 18.110, Residential Zones and Chapter 18.120, Commercial Zones. Additional standards apply in the River Terrace Plan District, as provided in Chapter 18.640, River Terrace Plan District.”
  • Accessory dwellingsAllowed (with conditions)

    Detached accessory dwelling units on lots with small form residential development wherever the housing type is allowed inside Tigard.

    • Detached ADUs are allowed only on lots with small form residential development and are prohibited as accessory housing for apartment, cottage-cluster, courtyard-unit, quad, and rowhouse development.
    • One detached ADU is allowed per lot; the total maximum number of dwelling units is three, including small form residential dwelling units.
    • Maximum ADU size is 800 square feet and maximum height is 25 feet.

    maximum detached ADU per lot: <= 1 · maximum detached ADU size: <= 800 square feet · maximum detached ADU height: <= 25 feet

    “A maximum of one detached accessory dwelling unit is allowed per lot. The total maximum number of dwelling units on a small form residential lot is three, including the units in the small form residential development. Detached accessory dwelling units are prohibited on lots with three small form residential dwelling units.”
  • Subdividing landRegulated (with conditions)

    Subdivision proposals inside Tigard city limits.

    • All subdivision proposals must comply with Oregon subdivision and partition statutes.
    • Lots may not be sold until the final subdivision plat is recorded.
    • Requirements include flood-damage minimization, adequate utilities and drainage.
    “The purpose of this chapter is to provide rules, regulations, and standards governing approval of subdivisions.”
  • Driveway accessRequired

    Development inside Tigard city limits, including new structures, remodeling, and specified changes of use.

    • Chapter applies to all development, subject to conflicts with subdivision requirements.
    • An access plan is required before land-use approval or development-permit issuance.
    • Driveways and drive aisles must have approved hard surfacing, turf grid, or open-joint pavers.
    “A plan demonstrating compliance with the access, egress, and circulation requirements of this Chapter must be provided prior to any land use approval or development permit issuance.”
  • Building in a floodplainRequired

    Construction or development within Tigard's mapped area of special flood hazard.

    • The permit applies to all structures, including manufactured dwellings, and other development including fill and other development activities.
    • Floodway encroachments increasing base flood elevation and certain other development require a Conditional Letter of Map Revision before the permit issues.
    “A development permit shall be obtained before construction or development begins within any area horizontally within the area of special flood hazard established in Section 9.10.030.B. The development permit shall be required for all structures, including manufactured dwellings, and for all other development, as defined in Section 9.10.020, including fill and other development activities.”
  • Permit feesVariable (with conditions)

    Electrical permits and investigation of unpermitted work inside Tigard city limits.

    • Electrical permit fees are set by City Council resolution.
    • For work begun without a required permit, a special investigation occurs before issuance; the investigation fee is in addition to the permit fee and equals the otherwise required permit fee.

    unpermitted-work investigation fee: equal to otherwise-required permit fee (In addition to the permit fee.)

    “An investigation fee, in addition to the permit fee, shall be collected whether or not a permit is then or subsequently issued. The investigation fee shall be equal to the amount of the permit fee that would be required by this code if a permit were to be issued.”
  • Permit processPartial

    Temporary certificate of occupancy applications inside Tigard city limits.

    • Applies to temporary certificates of occupancy, not the complete building-permit process.
    • A temporary certificate can be issued only by the Building Official or designee and expires on the approved date.
    “Applications for a Temporary Certificate of Occupancy must be submitted to the Building Official and include the following information:”

Still unanswered

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

  • Building permit — Residential construction inside Tigard city limits.
  • Owner-builder exemption — Owner-built housing inside Tigard city limits.
  • Minimum dwelling size — Principal dwellings in Tigard residential zones.
  • Minimum lot size — Principal residential lots in Tigard residential zones.
  • Lot coverage — Principal residential lots in Tigard residential zones.
10 more unanswered
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Short-term rentals

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 Tigard publishes no rule on the point, not that none exists. Washington County’s page lists the county offices to call.

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