School Modular/Portable Building Placement

Web page revised 1.1.26

The terms school modular or portable mean a factory-built structure that is used for educational purposes or to support educational activities.

Under certain circumstances, the placement of modular school buildings will require site plan review. If the size of the modular(s) triggers SEPA review (30,000 square feet in the urban areas; 12,000 square feet in the rural areas), a Type II site plan is required unless the applicant is a public school that provides their own SEPA review. Please refer to the Type II Site Plan Review handout and Clark County Code 40.520.040 under these circumstances.

This information applies to those circumstances when site plan review under Section 40.520.040 is not required.

School modulars that are exempt from site plan review must still obtain building permits and be reviewed for stormwater, critical areas, fire protection, and emergency access requirements.

Building permit and fire protection review

A placement permit (Commercial New – CMN) is required to install modular. A separate permit may be required for accessory structures such as ramps and decks related to the modulars.

A structural review of the modular building will not be required if the approved sets of drawings that are stamped and approved by the state are submitted to the county; however, the state does not certify that the foundation system of the modular meets county requirements. Other code issues may arise due to location on site and attachments such as deck, ramps and roof covers. Therefore, a structural review is required on the foundation system as part of the Placement Permit to determine if the structure will meet wind, snow, and seismic county requirements. See page three for placement permit submittal requirements.

The Fire Marshal’s Office will review the placement of the modulars for sprinkler requirements, fire flow, and emergency vehicle access requirements. Such issues should be considered early on in the applicant’s planning process.

Stormwater review

The county is required to meet all state rules relating to erosion control and stormwater quality and quantity control as part of its NPDES (National Pollution Discharge Elimination System) permit. Therefore, stormwater review is required on all development projects that create roof run-off to verify that the run-off either infiltrates into the ground or is managed through a stormwater system. The complexity of the stormwater review and fees depends on which Minimum Requirements in the Clark County Stormwater Manual are triggered.

In many cases, stormwater plan review and inspections can be approved by the Building Safety program in conjunction with the modular placement/plan review permit, provided:

  • The modular(s) were anticipated in a previously approved final engineering stormwater plan review; or,
  • The modulars are being placed over existing paved areas that received prior final stormwater review; or,
  • The modulars were not included in a prior stormwater plan, but the project is subject to no more than the Minimum Requirements 1-5 of the Clark County Stormwater Manual

If the project triggers Minimum Requirements 1-10, Public Works Development Engineering will need to review the stormwater plans and may need to perform inspections as well. In that case, contact Development Engineering at 564.397.4559 for an application and submittal requirements for Grading and Drainage – Plan Review.

Critical area review

A critical area review by staff will be required if the modulars have the potential to impact critical areas such as wetlands, habitat, or geohazards. If there are no critical areas on or near the site, or if the location of the modulars are clearly outside of critical areas, the critical area review will not be required. If a critical area review determines that the modulars will impact a critical area, revisions will be required or the appropriate permits will be necessary. There is no charge for a critical area review; however, if other permits are required, additional fees and process time will be required.

Application and review process

Step 1 - Application Submittal
Use the Submittal Checklist and follow the permit application guidelines.
As with any application, staff will perform a counter complete review. If all required information is not included, the application will not be accepted.

Step 2 - Setback and Critical Area Review
Permit Center staff will review the application for appropriate setbacks from property lines and existing buildings. Staff will also review the property to check for the presence of critical areas. If the proposed location of the modular(s) may have an impact on critical areas, a critical area review will be required by the appropriate staff.

Step 3 - Concurrent Reviews
Stormwater and critical areas reviews (when required) will be conducted at the same time as building plan and fire protection reviews.

Step 4 - Permit Preparation
Permit Center staff prepares the permit for issuance and notifies the applicant of its availability.

Approximate timelines

Building review will take approximately 30 days. Provided the stormwater review is not subject to MRs 1-10 and no critical area permits are needed, those reviews should not take longer than the building permit.

Who do I contact with questions during the review process?

Call Permit Center staff at 564.397.4078.

Submittal requirements

The following list identifies information to be included with the Application. All items must be submitted before the application can be accepted.

  1. Application form - The application form shall be completed and original signed in ink by the owner or owner’s authorized representative.
  2. Application fees - Fees will vary depending on the level and types of reviews that are needed.
  3. Site plan - A site plan drawn to scale with the following information:
    • A north arrow
    • The outline and dimensions of the property boundaries
    • Centerline of the public road or private road easement as applicable
    • Existing site-built structures with construction type and occupancy classification
    • Assumed property lines between site-built structures and portable units
    • Dimension(s) of portable units and accessory structures such as stairs, ramps, and landings and the distance from property lines and any other mobile, modular or permanent structure (Clark County Code requires at least eight feet between structures);
    • Ramps, stairs, and landings associated with the modular;
    • Submit a plan to show each cluster of un-sprinkled portable classrooms (the combined total cannot exceed 5,000 square feet)
    • Distance to any slopes, creeks or bodies of water
    • Location of wells and/or water lines
    • All easements crossing the property
    • Location of legal access from the subject property out to a county road if access is proposed via a private road easement
    • Location of septic tank, drainfield area and/or sewer line
    • Indicate scale of drawing
  4. Building Safety requirements - based on current IBC Requirements
    • Modular must have a Washington State Department of Labor and Industries approval of manufactured buildings (gold identity tag); one set of state-stamped drawings is required prior to final inspection for modular buildings
    • Obtain separate plumbing and mechanical permits as required per WAC 51-50, IBC Section 903.2.3
    • Provide plans, sections, details, and structural calculations for ramps, stairs, and landings associated with the modulars
    • Provide a code summary to show compliance with WAC 51-50, IBC Chapter 5
    • Separate engineered and stamped foundation plans in conformance with the State of
      Washington approved drawings
    • All modulars placed (new and relocated) must meet code requirements and setbacks from existing units regardless of when existing units were placed, minimum setback of 20 feet is required with code summary showing compliance
    • Modular classrooms closer than 20 feet from existing school buildings can be shown to comply with code as follows:
      • The new modular(s) is within the allowable area of the existing building. The modular building must meet the required construction type of the existing school building; see WAC 51-50, IBC Chapters 5 and 6
      • The new modular(s) is given an assumed property line between it and existing buildings; fire protection requirements per IBC Table 602 must be met; maximum aggregate area of clusters of modular school classrooms is not to exceed 6,000 square feet in order to exempt fire sprinklers; distance between buildings within each cluster may trigger additional requirements based on IBC Chapter 10.
    • Inspections are required for setbacks, footings, skirting, utility connections, stairs, and decks and railings.
    • Decks, landings and ramps
      • No separate building permit is required for a landing under 40 square feet with a single run of stairs and/or a single ramp (no additional landings) on a single modular.
      • A separate building permit is required for landing(s) over 40 square feet, multiple landings, multiple runs of stairs or ramps on a single modular.
      • A separate building permit is required for any decks, landings, and/or ramps serving more than one modular unit or any additional construction beyond the landing, stair and/or ramp (roofs, covers, walls, etc.) regardless of the number of modulars served

  5. Stormwater plan - submittal requirements will vary depending on which stormwater Minimum Requirements are triggered. Erosion control and stormwater plans similar to those approved for residential projects will suffice if:

    • The modular(s) were anticipated in a previously approved final engineering stormwater plan review; or,
    • The modulars are being placed over existing paved areas that received prior final stormwater review; or,
    • The modulars were not included in a prior stormwater plan, but the project is subject to no more than the Minimum Requirements 1-5 of the Clark County Stormwater Manual.

    If the project triggers Minimum Requirements 1-10, Public Works Development Engineering will need to approve the stormwater plans and may need to perform stormwater and erosion control inspections as well. Contact Development Engineering at 564.397.4559 for an application and submittal requirements.

Fee schedule

The following fees are required to be paid when the application is submitted.

Building Permit Fees
Placement Permit: $467
Plan Review: $533 
Issuance: $94
Fire Plan Review: $273
Fire Inspection (E occupancy): $190
Stormwater review and inspection of previously approved sites, or MRs 1-5 plans: $270

Fees for decks, stairs, and ramps are based on the square footage of the space, occupancy group, and construction type using the current IBC valuation and fee rate schedule.

Stormwater Engineering Review (when project is subject to MRs 1-10)
Grading and Drainage – Plan Review permit:
Stormwater Minimum Requirements 1-10: $3,293
Issuance: $94

Stormwater Inspection by Development Engineering (when required)
The below fee assumes less than 499 cubic yards of earth moving associated with the project
Grading and Drainage Permit – Inspection
Stormwater Minimum Requirements 1-10: $2,600
Issuance: $94

Erosion Control Inspection by Development Engineering (when required)
All Development Engineering projects also have an additional erosion control inspection fee. The fee listed assumes up to one acre of disturbed area.                
Annual Erosion Control Inspection: $2,450
Issuance: $94

Some of these fees may also be applicable to your application.
Septic/Sewer Connection: $122
Issuance:  $94
Water Connection: $122
Issuance: $94