I ran an experiment last quarter. I had a real-but-anonymized residential addition project — 1,800 square feet, single-story, slab-on-grade, conventional wood framing, simple structural scope. I sent the same drawing set and the same scope-of-work request to 12 structural engineering firms across six states. I asked each for a quote on review, calculations, and stamp.
The quotes ranged from $1,800 to $9,400. For the same project. Same drawings. Same scope.
The data
Here are the 12 quotes, in order from lowest to highest:
- Albuquerque, NM solo PE: $1,800
- Tucson, AZ small firm: $2,200
- Reno, NV small firm: $2,400
- Mesa, AZ mid-size firm: $2,800
- San Antonio, TX small firm: $3,100
- Phoenix, AZ mid-size firm: $3,400
- Cleveland, OH mid-size firm: $3,800
- Houston, TX mid-size firm: $4,200
- Sacramento, CA mid-size firm: $5,400
- Dallas, TX large firm: $5,900
- San Diego, CA large firm: $7,200
- Los Angeles, CA large firm: $9,400
Why the variation is this wide
Three factors, in rough order of impact:
**Geographic cost-of-living and overhead.** A solo PE in Albuquerque has lower rent, lower payroll, and lower E&O insurance than a 30-person firm in West LA. The Albuquerque PE can clear margin on $1,800; the LA firm can't. The cost-of-living spread between Albuquerque and LA accounts for maybe 40% of the variation.
**Firm size and overhead structure.** A 30-person firm has a project manager, a senior PE, a junior PE drafter, a coordinator, and admin. Each project carries that overhead. A solo PE in Reno carries no overhead. The same review takes the same number of engineering hours either way — but the billing structure is different.
**Brand and risk-aversion premium.** Some large firms charge a higher rate because they can. They've earned reputations, they have insurance to protect, and they use larger reviewer teams to lower their own risk. They are not necessarily doing more or better engineering than a solo PE on a typical residential addition. They are charging for a different position in the market.
What you actually get for the higher prices
I followed up with five of the firms after they sent quotes, asked clarifying questions, and got a sense of what each would do.
The cheapest three firms (Albuquerque solo, Tucson small, Reno small) would all do: structural calculations on the new framing, foundation review, lateral analysis, sheet markup with the structural notes, and a wet stamp. Standard residential structural review.
The most expensive three (Sacramento, Dallas large, San Diego, LA) would do: all of the above PLUS a project manager assigned to the file, a junior reviewer's first pass before the PE looks at it, separate sheets for the structural calcs (vs. notes integrated onto the architectural sheets), and a follow-up call after stamping to walk through the calculations with the GC. The deliverable is more polished. The engineering is comparable.
For a 1,800-square-foot residential addition with conventional framing, the polish doesn't change whether the addition stands up. The stamps are equally valid for permit purposes.
When the higher price is worth it
Three scenarios where I'd pay the premium:
- Complex structural scope: post-tensioned slab, steel moment frame, complex lateral system, hillside site with retaining requirements. The senior-PE-plus-team model catches things the solo PE might miss on first pass. For a residential addition, this rarely applies.
- Litigious AHJ: some Southern California cities are notorious for plan-check pushback on structural calcs. A larger firm with a known reputation and a track record at that AHJ can clear plan-check faster, even at 2-3x the fee. The fee delta is sometimes recovered in saved time.
- Specialty sealing: seismic retrofits, pool structures, swimming-pool foundation calcs, anything in a high-seismic-design-category zone. These are scope-specific specialties; large firms have the depth.
When the lower price is the right call
Most residential additions, all conventional wood-framed single-family work, ADUs, garage builds, and small commercial TIs with no structural changes can use a solo PE or small-firm structural engineer at the lower end of the range. The deliverable is functionally equivalent. The stamp is equally legal.
We coordinate with five solo PEs and three small-firm structural engineers across the Southwest. Average fee on our typical residential project: $2,200-$3,200. The range from large firms would be $5,000-$8,000 for the same scope.
Same stamp. Same legal weight. Same plan-check approval. The price spread reflects firm structure and brand, not engineering quality. For typical residential work, the lower-cost option is the right call.
If you're getting quotes for structural engineering on a project, get at least three. If two of them are 3x the third and the third is from a credentialed PE in good standing with the state board, the third is probably correct on price. The market doesn't enforce uniform pricing in this space; you have to do the comparison yourself.