Structural Engineering in Bellevue & the Eastside
ECD's structural engineer evaluates houses, sizes beams and foundations and stamps the calculations Eastside cities require for remodels and additions. You need one whenever a project changes how weight or lateral force travels through the house. A site evaluation with a written letter typically costs $600–$1,500; full engineering for an addition runs $4,000–$12,000.
Reviewed by Daniel R. Whitcomb, PE · WA PE 48217
What does a residential structural engineer do on a remodel?
A house is a chain of load paths. Roof weight, snow, people and furniture travel down through rafters, joists, walls and beams into footings and then the soil. Wind and earthquakes push sideways and are resisted by shear walls, hold-downs and the connections between floors and foundation. Any remodel that cuts into that chain, by removing a wall, adding a story or opening a large window, has to rebuild it somewhere else. The engineer's job is to decide exactly where, with what members and with what connections, and to prove it in calculations the building department can check.
At ECD the engineer also builds what they design, through our own construction team. That changes the work in a practical way: the engineer chooses solutions the crew can install in the space available, and the estimator prices the real solution rather than a placeholder.
What is included in ECD's structural engineering service?
- A site visit to trace the existing load path through the attic, floors and crawlspace or basement.
- Beam, header, post and connection design in sawn lumber, engineered lumber (LVL, PSL, glulam) or steel.
- Footing and foundation design for new point loads, additions and repairs.
- Lateral design: shear walls, hold-downs, straps and diaphragm checks for wind and earthquake loads.
- Stamped calculations and structural drawings formatted for city plan review.
- Written responses to plan review correction comments on structure.
- Field observation of structural work before it is covered, on projects we build.
What is not included
A geotechnical report on soil and slope stability is prepared by a separate geotechnical engineer when a site has steep slopes, landslide hazard areas or questionable soil; we coordinate that firm and use its recommendations. Property surveys, architectural layout design and special inspections required by some cities for large commercial projects are also separate scopes.
How does an engineering engagement run?
- Request and photos1–3 days
You describe the change and send photos; we confirm whether a visit is the right first step.
- Site evaluationOne visit, 1–2 hours
The engineer measures spans, identifies framing direction and sizes, and looks at bearing points and foundation condition.
- Analysis and design1–3 weeks
Loads are calculated, members sized and connections detailed. Options are compared when they affect cost or ceiling height.
- Drawings and stamped calculations1–2 weeks
Framing plans, foundation plans and details are issued with the engineer's Washington PE stamp.
- Plan review responses1–2 weeks per round
Structural correction comments from the city are answered in writing with revised sheets if needed.
- Field observationDuring construction
The engineer checks beams, posts, hold-downs and footings in place before inspection and cover.
How much does structural engineering cost on the Eastside?
| Scope | Typical fee | Turnaround |
|---|---|---|
| Site evaluation with written letter | $600–$1,500 | 1–2 weeks |
| Single beam or header with detail | $900–$2,200 | 1–2 weeks |
| Wall removal package (beam, posts, footings) | $1,800–$4,000 | 2–3 weeks |
| Foundation evaluation report | $1,200–$3,000 | 1–3 weeks |
| ADU structural drawings and calcs | $3,500–$9,000 | 3–5 weeks |
| Addition or second-story structural set | $4,000–$12,000 | 3–6 weeks |
When do Eastside cities require stamped engineering?
Washington cities adopt the International Residential Code with state amendments. The IRC lets simple, regular framing be built from its prescriptive tables, but section R301.1.3 requires an engineered design for any part of a house that falls outside them. In practice, a building department will ask for a Washington-licensed engineer's calculations for beams replacing bearing walls, point loads on existing foundations, additions over existing structure, irregular lateral systems and most foundation repairs.
Bellevue, Kirkland, Redmond, Sammamish, Issaquah and most other Eastside cities take applications through MyBuildingPermit.com; Seattle uses the Seattle Department of Construction and Inspections portal. Code text is available from the Washington State Building Code Council and in the ICC code library. For city-specific review requirements, see our structural plans and permits service.
A recent engineering problem we solved
PROJECT · BELLEVUEA 16-foot bearing wall replaced by a flush beam in a mid-century Lake Hills houseThe ceiling joists lapped over the wall and carried part of the roof. The engineer sized a flush LVL beam with hangers so the ceiling stayed flat, and two new footings in the crawlspace took the point loads.Engineering questions
Structural engineering FAQ
Deciding whether you need an engineer at all? Read Do I need a structural engineer for my remodel.
How much does a structural engineer cost in Bellevue?
For a single-family home, a site evaluation with a written letter usually runs $600 to $1,500, a single beam calculation $900 to $2,200, and a full structural set for an addition or second story $4,000 to $12,000. The fee depends on how much of the house is affected, not on the construction budget. When ECD also builds the project, engineering fees are credited toward construction.
How soon can your engineer visit my house?
Site visits are usually scheduled within one to two weeks of your request. If you describe active movement, such as a beam that is visibly deflecting, a floor that dropped suddenly or a crack that is widening, tell us on the first call and we prioritize the visit. Send photos ahead so the engineer arrives knowing what to look at.
What does a structural site evaluation include?
The engineer identifies how the roof and floors are framed, measures spans, locates bearing walls and posts, checks the foundation and crawlspace or basement for cracks, settlement and moisture damage, and notes past alterations. You get a written summary of what was found, what the project will require structurally and what drawings the city will expect.
Will the city accept your calculations if another contractor builds the project?
Yes. Stamped calculations and drawings from a Washington-licensed engineer are accepted by Eastside building departments and Seattle regardless of who builds. If another contractor builds, our engineer remains available for plan review questions and field changes under a separate agreement, since we are not on site every day.
Do I also need a geotechnical engineer?
Only on some sites. If the property is in a mapped steep slope or landslide hazard area, has fill or soft soil, or the project adds significant foundation load, the city may require a geotechnical report. Our structural engineer tells you at the site visit whether one is likely and coordinates the geotechnical firm so its recommendations flow into the foundation design.
Does the engineer inspect the work during construction?
On projects ECD builds, yes. The engineer checks beams, posts, connectors, hold-downs and footings after installation and before they are covered or inspected by the city. On projects built by others, field observation visits are available and are often requested by the building department for unusual structural work.
Free estimate · Bellevue office
Talk to the engineer before you commit to a plan
A site visit, a scope conversation and a written budget range, at no cost.