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Building Codes

Building Codes

Building Codes

Residential One- and Two-Family Dwellings and Accessory Structures

In order to provide a timely but comprehensive code compliance review, complete construction plans and specifications are needed. Incomplete plans and specifications may delay permit processing. Please see the One- and Two-Family Dwelling Building Permit Application Checklist for a list of requirements.

We will review your submittal plans for completeness at the time of permit application and give you a Residential Plan Submittal Checklist.

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Design Criteria and Current Codes

Seismic Design

OSSC 1613

  • Seismic Design Category – D

Wind Design

OSSC 1609
Wind Exposure is site specific and it is the design professional's responsibility to determine the exposure category selected for the area of construction.

Basic Design Wind Speed Special Wind Region*
Risk Category I 92 mph 115 mph
Risk Category II 98 mph 120 mph
Risk Category III 105 mph 130 mph
Risk Category IV 109 mph 130 mph

* Sites located within a special wind region shall be verified online.

Soil Load-Bearing Values

OSSC 1806
These presumptive design soil load-bearing values shall be used if a geotechnical report is unavailable for the project.

Class of Soil Material ML, Inorganic Silts and Clayey Silts
Vertical Foundation Pressure 1,500 psf
Coefficient of Friction 0.25

Soil Lateral Loads

OSSC 1610
These presumptive design soil lateral loads shall be used if a geotechnical report is unavailable for the project.

Active Pressure 45 psf
At-Rest Pressure 100 psf

Snow Loads

OSSC 1608

Foundation Frost Protection

OSSC 1809.5

To protect foundations from frost, they must be installed below the determined frost depth. The table below provides the minimum top of footing depth from grade based upon the elevation where the project is located.

Frost depth
Project site elevation Minimum frost depth to bottom of footing
Below 2,500 ft 12 inches
2,500 to 4,000 ft 18 inches
Above 4,000 ft 24 inches

Design criteria for residential structures

Seismic Design

ORSC Figure R301.2.2.1

Wind Design

ORSC Table R301.2(1)

  • Basic Design Wind Speed – 98 mph

ORSC Table R301.2(1) 

  • Special Wind Region,
    Basic Design Wind Speed - 120 mph

Soil Load-Bearing Values

ORSC Table 401.4.1
The design load-bearing values shall be used if a geotechnical report is unavailable for the project.

  • Class of Soil Material – ML, Inorganic Silts and Clayey Silts
  • Vertical Foundation Pressure – 1,500 psf

Snow Loads

OSSC 1608

Foundation Frost Protection

OSSC 1809.5

To protect foundations from frost, they must be installed below the determined frost depth. The table below provides the minimum bottom of footing depth from grade based upon the elevation where the project is located.

Frost depth
Project site elevation Minimum frost depth to bottom of footing
Below 2,500 ft 12 inches
2,500 to 4,000 ft 18 inches
Above 4,000 ft 24 inches

Current Adopted Codes

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Building Codes

We provide permitting, plan review and inspection services. These services ensure that minimum building standards are met for your safety, and the safety of all building users and occupants.