Structural engineering · Hillsboro, OR
Structural Engineering Services in Hillsboro, OR
Connect with engineering firms serving Hillsboro and the greater Portland metro area. Common work runs from load-bearing wall removals and additions to ADUs, foundation upgrades and more.
Also searched as: residential structural engineer Hillsboro OR · stamped structural calculations Hillsboro · Hillsboro ADU structural engineer · beam calculations Hillsboro OR · structural engineer near me Hillsboro
Local code & loads
Hillsboro building code & ASCE 7 design loads
Hillsboro enforces the 2025 Oregon Structural Specialty Code (OSSC), based on the 2024 IBC. Stamped calculations submitted for permit reference the design parameters below.
Values shown for reference only — project-specific values from the ASCE 7 Hazard Tool should be used for engineering design at the actual project address.
ASCE 7 design parameters
Default values used for most residential and light-commercial projects in Hillsboro. Site Class and seismic spectral values may shift based on geotechnical investigation.
| Building code | 2025 Oregon Structural Specialty Code (OSSC), based on the 2024 IBC |
|---|---|
| ASCE 7 edition | ASCE 7-22 |
| Seismic Sₛ | 0.99g |
| Seismic S₁ | 0.4g |
| Site class | Default |
| SᴅS | 0.83g |
| Sᴅ₁ | 0.57g |
| Seismic Design Category | D |
| Ultimate wind speed | 96 mph |
| Ground snow load | 25 psf minimum per OSSC (confirm the site-specific value per ASCE 7-22 and local jurisdiction), |
Risk Category II assumed for typical residential and light commercial use — confirm with your engineer if the occupancy or use may require a higher category.
Hillsboro is a Seismic Design Category D area, with the Cascadia Subduction Zone and western Washington County crustal faults setting the demand. The Tualatin Valley's deep clay and silt deposits hold water and move through wet and dry cycles, so foundation design and drainage matter on most sites. The values below are regional placeholders only. Always pull site-specific values from the ASCE 7 Hazard Tool (https://ascehazardtool.org) for the actual project address.
Common projects engineers design in Hillsboro
The work engineers handle frequently in Hillsboro and the surrounding Washington County.
- Load-bearing wall removals and open-concept remodels
- Room additions and second-story additions
- Accessory dwelling units (ADUs) and detached units
- Foundation design and repair in clay and silt soils
- Seismic retrofit of older wood-frame homes
- Deck, patio cover, and porch structures
- Retaining walls on graded lots
- Rooftop solar array structural verification
What's different about Hillsboro
Local conditions that affect structural design
City-specific factors that show up in many Hillsboro calculations — and the things plan reviewers look for.
Permits
Where to submit your Hillsboro permit
Stamped calculations from clearspan are submitted directly to the City of Hillsboro Permitting Center. Most residential structural submittals are reviewed online.
Building department
City of Hillsboro Permitting Center
150 E Main Street, 4th Floor, Hillsboro, OR 97123
(503) 681-6153
Submittal notes
Hillsboro's Permitting Center handles building permits inside the city. Properties on unincorporated Washington County land go through the county instead. The area's clay and silt soils make a geotechnical report a common requirement for new foundations and additions. Confirm the jurisdiction before submitting.
FAQ
Structural engineering in Hillsboro — FAQs
The questions Hillsboro contractors and homeowners ask most often.
Do I need an engineer to remove a wall in my Hillsboro home?+
Does Hillsboro require stamped structural plans for an ADU?+
How quickly can I get stamped calculations for a Hillsboro permit?+
Nearby cities
Structural engineers in other Portland Metro cities
Browse city pages for nearby jurisdictions.
Need a beam designed quickly in Hillsboro?
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