Structural drawings
Framing plans, foundation plans and shear-wall schedules keyed to your architectural set — sheet-numbered and plan-check ready.
ADU structural engineering · California
Get Your ADU Through Plan Check — Without Hiring a Full-Service Firm.
Foundation, framing and lateral engineering for detached ADUs, garage conversions and attached units — a complete structural package coordinated to your architect's set, at one fixed price.
What kind of ADU?
60 seconds · Free · No obligation
Step 1 of 4
- California PE-licensed engineers (CA & NV)
- Fixed-price quote — no hourly billing
- No commitment until you accept
- Corrections included per proposal
What kind of ADU?
60 seconds · Free · No obligation
Step 1 of 4
California PE-licensed engineers
Fixed-price proposals
Permit-ready documents
Corrections handled
How it works
From this page to permit-ready plans.
- 1
Today — about a minute
Answer a few questions & tell us where to send the quote
Plans, photos, sketches or a permit letter. Don't have everything? Send what you've got.
- 2
Within 1 business day
Free scope review → fixed-price proposal
A defined scope, one price and a stated turnaround. Your quote stays valid for 30 days.
- 3
After you accept online
Engineering starts — track it live
E-sign, pay the deposit by card or ACH, and watch status through delivery on your dashboard.
Your quote
One fixed price. In writing. Before you commit.
- Free scope review — you pay nothing to find out what your project needs
- A fixed price for a defined scope; additional work is only ever quoted, never surprise-billed
- Your quote stays valid for 30 days while you line up your contractor
- Plan-check correction rounds included per the proposal
What California plan check expects on an ADU
- A foundation design matched to your soil and slab conditions
- Roof and floor framing plans with member sizes — not just "per code"
- A lateral (shear wall) design; California reviewers rarely waive it
- Details tying the structure together: holdowns, straps, connections
- Calculations that match the drawings sheet-for-sheet
Sound familiar? Answer 3 questions and get your fixed-price quote →
Deliverables
What you receive
A complete, engineer-reviewed structural package — the same documents a full-service firm produces, delivered through your project dashboard.
What you receive
Structural calculations
Gravity and lateral calculations that match the drawings, member by member, so plan checkers can follow the load path.
Details & connections
Beam-to-post, holdown, footing and connection details your framer can build from — no guesswork on site.
Plus permit-correction responses and revisions through the same project. Get your quote →
Pricing, honestly
What actually drives the price
No two projects price the same — these are the factors our engineers scope. You get one fixed number after a free review, not an hourly meter.
Size and stories
A 400 sq ft studio and a 1,200 sq ft two-bedroom carry different framing and lateral work.
Foundation type
Slab-on-grade on a flat lot is the simplest case; slopes and additions over garages add design work.
Conversion vs. new build
Garage conversions reuse structure but often need upgrades — openings infilled, footings verified.
Jurisdiction requirements
Some cities have pre-approved paths and specific submittal formats; we note the right code basis for yours.
The risk is on us: free scope review, fixed price, and no commitment until you accept.
Get My QuoteWhy JAT
Built like software, reviewed like a firm.
The engineering is the same discipline you'd expect from any licensed structural firm. The way you order it, track it and receive it is not.
Comparison with a traditional engineering engagement
| The usual way | With JAT Engineering | |
|---|---|---|
| Getting a quote | Phone tag, site visit scheduling, waiting weeks for a proposal | Upload plans or photos online; defined scope and fixed price after review |
| Knowing where things stand | Emails and voicemails | One status per project, visible in your dashboard 24/7 |
| Documents & revisions | PDF attachments scattered across inboxes | Versioned drawings, calcs and permit comments that stay with the project |
| Plan-check corrections | A new conversation and often a new invoice | Submitted back through the same project — rounds included per proposal |
| Repeat projects | Start from scratch every time | Duplicate a past project or use a template — under two minutes |
| Paying | Paper invoices and checks | Card or ACH online; deposit to start, balance before final release |
Before you ask
What does ADU structural engineering cost?+
ADUs are quoted per project after a free scope review — one fixed price covering the full structural package. There's no commitment until you accept, and correction rounds are included per the proposal.
My architect's plans are done. What do you need?+
Upload the architectural set (PDF is fine). We coordinate our structural sheets and calcs to it, keyed to the same grid and sheet numbers, so plan check reads one coherent package.
Do I need a soils report?+
Not always. Many single-story ADUs can use code-prescribed soil values. If your site has known expansive soils or slopes, we'll flag it during the free scope review — before you're committed.
Can you work with my city's ADU program?+
Yes. We note the correct jurisdiction, code cycle and submittal format on the set, and if the reviewer issues structural comments we respond through the same project.
Get Your ADU Through Plan Check — Without Hiring a Full-Service Firm.
Three questions, a free scope review, and a fixed-price quote — usually within one business day.
No commitment required to submit a project for review.