Monmouth, Oregon Building Permit Guide

In Monmouth the City’s own Building Department issues every building permit: structural, electrical, mechanical, plumbing and manufactured home placement. Contractors apply and pay in Oregon ePermitting, and homeowners can apply online or drop plans at City Hall. Structural fees come from a valuation table, with plan review at 65% of the permit fee, a 3% technology fee and the 12% state surcharge.

The department works from Monmouth City Hall, 151 Main Street W, under Building Official Greg Lewellyn (503-751-0138). Monmouth, a Polk County city of 11,543 people in the Census estimate for 2025, also runs its own electric utility, Monmouth Power & Light, which reviews new projects alongside the Building, Planning and Public Works departments.

The City permits land inside Monmouth’s city limits. Land outside the city in unincorporated Polk County goes to Polk County Community Development.

What requires a building permit in Monmouth?

Monmouth’s application list shows what it permits: new single-family homes, duplexes, apartment buildings and commercial buildings and remodels, plus building relocation, house moving, demolition, signs, fire sprinklers and suppression systems, rooftop solar and manufactured home placement. Small residential projects are measured against chapter 1 of the 2026 Oregon Residential Specialty Code, mandatory statewide since October 1, 2026; the City’s own code page still lists the earlier editions.

What Monmouth decides and what the state holds

Oregon’s specialty codes set the technical rules; the 2025 structural code has been mandatory since April 1, 2026, and the 2026 residential code’s permit chapter since October 1, 2026. Monmouth decides its fees and forms, its submittal rules, its zoning and design standards, its utility connections and its system development charges. The City’s 2024 residential plan checklist places Monmouth in Seismic Design Category D1.

Oregon’s building code and its exemptions are the same in Monmouth as everywhere in the state, and an exemption from the building permit is not an exemption from zoning, land use or a trade permit. Site snow, wind and seismic values come from the state’s Oregon Design Criteria Hub. How Oregon’s statewide code works

Monmouth building department: who handles permitting

Because Monmouth is a full-service jurisdiction, one counter handles all four trades: the state lists the City for “all building permits” in its building department directory. Community Development on the second floor of City Hall takes land use applications, Public Works covers water, sewer and stormwater, and Monmouth Power & Light reviews each building application for electric service. Septic systems are permitted by Polk County Community Development as DEQ’s agent.

Permit types

Residential permits

Residential electrical, mechanical and plumbing permits can be applied for, paid for and received online at any hour. A homeowner picks the matching application from the City’s list, then either drops the plans at City Hall or uses the online application; the City asks homeowners not to email applications. Staff email a fee estimate once the application is processed, payment goes by check to the Building Department or in person, and the City calls or emails when the permit is approved. For an ADU, the City’s guide says the Building Official needs drawings prepared by a design professional or engineer, and the ADU rules are in Monmouth City Code 18.30.030. The guide also asks owners to confirm with Public Works that water, sewer and stormwater service can reach the new unit.

Building or remodeling a home here? Alliance handles residential permit applications, so the crew isn't waiting on the counter.

Commercial permits

For commercial buildings and remodels and apartment buildings of three or more units, as for new homes and duplexes, contractors assemble a full package: the Development Review Checklist, the structural, electrical, mechanical and plumbing applications, the plan review requirements sheet, a site plan, engineering and truss documents, and a deposit set by the City according to square footage. Where fire and life safety plan review applies, it adds 50% of the structural permit fee, and deferred submittals and special inspection agreements have their own forms.

For tenant improvements and new commercial builds, Alliance handles commercial building permits through issuance. More on this: commercial building permits explained.

What comes before the building permit

A pre-application conference form is available for projects that need one. Land use applications go to Community Development at City Hall, between 8 a.m. and 5 p.m., and are searchable in Oregon ePermitting. Its forms cover site plan review, design review, conditional uses, variances, home occupations, historic alterations and demolitions, and floodplain development permits, with a zoning checklist and attachments for fences and accessory structures; land use fees reset each July, and the current table runs to June 30, 2027. Public Works needs site plan details with the building application to set the system development charges. The scaled site plan itself has to show the lot and setback dimensions, corner elevations, easements and the driveway, the building footprint with decks, any well or septic system, utility lines, known fill, flood hazard areas, wetlands or riparian areas, lot and impervious area, existing buildings and surface drainage. As a participating NFIP city, Monmouth regulates mapped flood areas through the floodplain development permit listed above; FEMA dates its effective map December 19, 2006.

Monmouth permit costs and fees

The structural and mechanical valuation table on the City’s forms page is headed “effective date January 1, 2018”. The structural application form, effective June 1, 2023, prints a higher minimum and flat fee of $74.27, where the 2018 table starts at $72.60, and the City emails a fee estimate once it has processed an application. Both documents set plan review at 65% of the permit fee, and the 2023 forms add a 3% technology fee and a state surcharge line of 12% of the permit fee.

System development charges are separate. The City’s summary effective July 1, 2026 lists $2,485 for water and $4,837 for sewer on a single-family unit with a 5/8-inch meter, a storm charge of $0.135 per square foot of roof and paving, and a parks charge of $2,927 for a detached house. The transportation SDC table for 2025 lists $5,343 per detached single-family dwelling.

Trade permits and who may pull them

Monmouth runs its own electrical program. The electrical application, effective June 21, 2023, prices a new dwelling of 1,000 sq ft or less at $165 plus $32.28 for each extra 500 sq ft, a service of 200 amps or less at $99, extra inspections at $66 and the minimum permit at $79, then adds the 3% technology fee and the 12% state surcharge. The form also prices a master electrical permit at $79 plus $66 for each added inspection, billed at the end of each calendar year, and a temporary service needs Monmouth Power & Light’s $50 connection fee before the utility will energize it. Mechanical permits start at a $60.50 minimum.

How to apply for a Monmouth building permit

Review, corrections and what causes delay

The plan review requirements sheet lists what reviewers expect: foundation plans and cross sections, floor and framing plans, elevations, wall bracing or lateral analysis, beam calculations, truss details, energy code compliance and stamped engineering for shear walls, trusses and retaining walls over 4 feet. A site that slopes more than 4 feet needs 2-foot contours on the site plan, and plans that show copyright violations cannot be reviewed. An application that is not turned into a permit within 180 days of being accepted as complete expires.

Inspections in Monmouth

The City inspects Monday to Thursday, between 8 a.m. and 3 p.m., and contractors book inspections automatically through ePermitting, by app or by phone. Required inspections are listed on the permit card, and the 2024 residential checklist reminds builders that changes to approved plans need the department’s approval and that a final inspection must pass before anyone moves in. Re-inspections and inspections outside business hours are charged at $66 an hour under the valuation sheet.

The City’s forms list ends with its “final documents”: the high-efficiency lighting, moisture content and air barrier certifications that builders complete for the energy code. Because the City also runs the electrical program, electrical inspections are booked and done through the same department as the structural ones, and the plumbing and mechanical inspections are too.

Monmouth permit search and official resources

Permits and land use applications filed since the City joined ePermitting can be found with the public search in Oregon ePermitting by address or permit number. The City’s building inspection program operating plan, on file with the state Building Codes Division and at City Hall, is available on request.

• Monmouth Building Department
• Monmouth building permit applications and forms
• Structural and mechanical permit fees by valuation
• Structural building permit application (June 2023)
• Electrical permit application and fees (June 2023)
• Plan review requirements
• Residential plan checklist (July 2024)
• Monmouth land use applications
• Monmouth system development charges
• Monmouth ADU guide
• Oregon ePermitting
• 2026 Oregon Residential Specialty Code, chapter 1 (permits and exemptions)
• DEQ onsite septic agents by county
• FEMA Community Status Book for Oregon
• Oregon Construction Contractors Board

Monmouth building permit FAQ

Does Monmouth issue electrical permits?

Yes. Monmouth is a full-service jurisdiction and issues structural, electrical, mechanical, plumbing and manufactured home permits itself.

How much does a building permit cost in Monmouth?

The valuation sheet starts at $72.60 and the 2023 structural form at $74.27; plan review is 65% of the permit fee, plus a 3% technology fee and the 12% state surcharge.

Can a homeowner apply on paper in Monmouth?

Yes. Homeowners may drop plans off at City Hall or apply online; the City asks that applications not be emailed.

When does Monmouth do inspections?

Monday to Thursday, 8 a.m. to 3 p.m., booked through Oregon ePermitting.

Do I need a permit for a shed in Monmouth?

Not for a nonhabitable one-story shed of 200 sq ft or less that stays under 15 feet to the average roof height, but the zoning checklist’s accessory structure rules still apply.

How many plan sets does Monmouth need?

One set when filing electronically. On paper, a single-family home needs two sets and multifamily, commercial or industrial work three, with engineering and truss documents in the same number.

Which City departments review a building application in Monmouth?

Building, Planning, Public Works and Monmouth Power & Light all review it under the Development Review Checklist, and Public Works uses the site plan to set the SDCs.

What are the SDCs for a new house in Monmouth?

From July 1, 2026: $2,485 water, $4,837 sewer and $2,927 parks for a single-family unit, plus $0.135 per sq ft of impervious area for storm and the transportation SDC, $5,343 per house in the 2025 table.

Simplify Monmouth permitting with Alliance Permitting

Alliance Permitting is a permit documentation and submission company in Oregon. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Monmouth permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.