When is Structural Engineering Required?

Under the International Residential Code (IRC), when a project does not comply with the prescriptive structural provisions, engineering is required. Under certain conditions based on the site locations, soil conditions, scope of work and the proposed design engineered drawings, details and calculations may be required.

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.

Following are some examples of when engineering is required. However, there are other instances when engineering will be 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 or subject to a surcharge
  • Depending on site location, soil conditions, presence of fill or a soils report from a Geo-tech engineer may be required

Show All Answers

1. Why is a permit required?
2. When is a permit required?
3. How do I apply for a permit?
4. Residential Building Permit Process
5. Electrical, Mechanical and/or Plumbing Work
6. Research
7. Things to Consider
8. What are setbacks?
9. Are there any site constraints on your property?
10. When is Structural Engineering Required?
11. Fees