When is Structural Engineering Required?

Under the International Residential Code (IRC), engineering is required when a project does not comply with the prescriptive structural provisions. Structural engineering shall include engineered drawings, details, layouts, calculations, lateral analysis and gravity load design. Two (2) copies are required. Engineering calculations shall be based on design loads and shall be noted on structural plans and calculations.

The following are some examples of when engineering is required. 

  • Pole Buildings;
  • Insulated Concrete Form (ICFs) wall construction;
  • Structural Insulated Panel (SIPs) wall and roof construction;
  • Dormers and second floor additions;
  • Moving or removing walls, beams, or headers;
  • Decks over 9’ from grade to underside of beam;
  • Decks supporting hot tubs and cantilevered decks;
  • Second story decks – new or replacement;
  • Retaining walls over 4’ in height (subject to a surcharge);
  • And a geo-tech report may be needed depending on site location, soil conditions, presence of fill, or certain soils.

The above list are just some instances when engineering will be required. If you have specific questions please call the building line at 360-342-5046 or e-mail us at comdev.info@cityofbg.org

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1. Why is a permit required?
2. When is a permit required?
3. What is needed to apply?
4. What is the Residential Building Permit Review Process?
5. What are setbacks?
6. When is Structural Engineering Required?
7. Do I need a permit for electrical, mechanical, and/or plumbing work?