Structural engineer: what to know

What the job involves, what changes the price, and what to ask a pro.

What structural engineer is

A structural engineer is a licensed professional who analyzes how a building carries its loads, and prepares calculations and drawings for beams, foundations and framing. People hire one when a project changes the load path, when a building shows signs of movement, or when a permit requires stamped structural drawings.

Signs you need it

  • You plan to remove or move a wall, open a large span or add a second story to an existing house
  • A floor, a beam or a wall shows sagging, cracks or movement that a contractor cannot explain
  • Your building permit requires stamped structural drawings for the framing, the foundation or the roof
  • You want to add a deck, a porch, a carport or a heavy roof load, and the existing structure must be checked
  • A structure has been damaged by fire, water, a storm or a vehicle, and you need an assessment before repairs

What the pro does

  • The engineer reviews the existing drawings, if any, and visits the site to see the framing, the foundation and the connections
  • They measure the members, the spans and the bearing points, and note the signs of damage or movement
  • They model the loads, such as the floors, the roof snow, the wind and the earthquake forces that apply to the site
  • They calculate the sizes of new or repaired members, the connections and the foundation needed
  • They prepare drawings and specifications for the framing, the beams, the foundation or the repair
  • They review the contractor's work or shop drawings and issue a letter or a stamp for the permit when the design is approved

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Scope of the work, such as a single beam, a full house assessment or a complete structural design
  • Number of members, spans and connections that must be checked or designed
  • Amount of existing documentation available, since missing drawings take longer to verify
  • Site visits and the need for testing, such as material samples or core tests
  • Whether the project needs an engineer's report, a letter, stamped drawings or construction review
  • Complexity of the loads, such as heavy equipment, large snow loads or unusual roof shapes
  • Revision count if the design changes after the first drawings are issued

What a written quote should spell out

  • Scope of the engineering, such as a site visit, calculations, drawings and a stamped letter
  • Which members, connections or foundation elements are covered by the design
  • Number of site visits and what the engineer will examine at each one
  • Testing included or excluded, such as materials testing or core samples
  • Drawings and specifications delivered, with their revision and date
  • Revision terms and how changes after the first issue are priced

Questions to ask before you hire

  • Are you licensed in this state, and can I check the license with the state licensing board?
  • What exactly will you examine on site, and what will the report or the drawings include?
  • Will your stamp cover the design I need for the permit, and which sheets will you stamp?
  • How do you handle the loads for the snow, the wind and the floors in my area?
  • Can you review the contractor's plan or shop drawings for the same work?
  • How many revisions are included, and what triggers a new charge?
  • What if your findings show the structure needs more repair than I expected?

Red flags

  • They offer to stamp a design without visiting the site or reviewing the existing structure
  • They promise a structural result before measuring the members or the connections
  • They are not licensed in the state where the building sits
  • They will not describe what the letter or the stamp covers

What you can do yourself

You can gather existing plans, photos of the framing, a list of the changes you want, and notes on any cracks or movement with dates. Do not size beams, decide the load path or rely on rough calculations to remove a wall or change a span yourself. Ask a licensed structural engineer to design or confirm the change before any work starts.

Licenses and permits

Structural engineers are commonly licensed, and the right to stamp structural drawings is usually restricted to licensed professionals. Check with your state licensing board for the engineer's license status and the stamping rules for the work, and ask your local building department which stamped drawings it requires.

Structural engineer questions

Do I need a structural engineer to remove a wall?

Often, yes. A wall that carries load needs a designed replacement beam and posts. Many building departments require stamped drawings for this work, and the engineer can confirm whether the wall is load-bearing before any cut is made.

What is the difference between an engineer's letter and stamped drawings?

A letter typically states the engineer's findings or approval of a specific item. Stamped drawings show the design in full detail for permit and construction. Ask which one your building department and your contractor need.

Can a structural engineer inspect a house I want to buy?

Yes. An engineer can assess visible structural conditions. The report covers what is visible on the day of the visit, so ask what is excluded and whether a separate inspection of other systems is needed.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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