The drawing review tool I wish I'd had years ago.
I'm a licensed structural/civil engineer. Structuraly is a free side project that runs an AI-assisted QA/QC pass on structural drawing sets. It traces sections back to plans, checks the general notes against what's drawn, follows the load path, reviews Division 03 concrete specs, and now checks calculation packages. The goal is to catch the small misses before they turn into RFIs.
No account, no API key, nothing to install. Just your email, so I can ask how it went. You get an Excel report and a quick feedback box.
Every set gets the same careful, tiring first pass.
Before a set goes out, someone traces every section cut back to its plan, matches schedules to callouts, and reads the general notes against what's actually drawn. It takes hours of deep focus. The misses that slip through are almost never hard engineering. They're the small things: a callout pointing to a detail that doesn't exist, a footing at 3000 psi in the schedule and 2500 psi in the notes, a hold-down that never reaches the foundation.
I wanted to see how much of that first pass a machine could take on, so the hours could go into engineering judgment instead. Structuraly is the answer so far. I work on it on evenings and weekends, test it on public bid sets, and rewrite its rules every time it gets something wrong.
It isn't a company or a product. It's a tool I care about, and one that I wish I had.
Six reviews, each a written method, not a black box.
Each review follows a "skill": a written method with reference files, the same way I'd brief a junior engineer. The skills are open on GitHub, so you can read exactly what it's checking for and tell me where it's wrong.
Cross-reference trace
Sections against plans, detail callouts against details, schedules against what's drawn, and gaps in completeness.
General notes QA/QC
Inventories every material actually drawn, then checks the notes for coverage, code-required design data, and values that disagree with the schedules.
Gravity load path
Traces load from roof or floor down to the foundation and confirms the actual connection at every junction, not just that one is implied.
Lateral load path
Follows the seismic path from diaphragm to soil and checks the design basis, collectors, wall anchorage, and system detailing.
Concrete spec QA/QC (Division 03)
Reads the written specification instead of the drawings. Checks cross-references against every section in the book, outdated or unused standards, exposure and mix requirements, acceptance criteria against ACI 318, values that disagree between sections, and editing left unresolved. Built from 20 patterns found across six public spec sets in four template families.
Calc package QA/QC
Checks a calculation package the way a checker with a red pen does: every input traced to a source, governing numbers recomputed, code editions and equations confirmed, load combinations compared with the factors actually used, missing calcs listed, and results followed onto the drawings. Reads handwritten pages, worksheet software, spreadsheets, and design-software output, and works for in-house calcs and delegated-design submittals. You get a comment log ready to send to the designer.
Drop a PDF
A structural set, any size. Leave out the sheets you don't need.
It reads the sheets
It uses the PDF's own text for exact values, plus images, with zoom for dense notes and schedules.
Pick a review
It runs that skill's method on the sheets you chose, with sheet references on every finding.
Mark it up
You get an Excel report with a "Your verdict" column. Mark what's real and what isn't, and email it back.
✓ PASS Risk Category III is the same under Wind and Seismic. (S0.01)
⚠ WARN The footing schedule gives f'c = 3000 psi (S2.01); the general notes give 2500 psi. (S0.01)
⚠ WARN Detail 7/S5.02 is called out on S2.01, but S5.02 has no detail 7.
✗ CRIT Hold-down at grid C/4 (S3.01): no anchorage to the foundation is shown.
Every finding names its sheet, so you can check it in seconds.
What it is, and what it isn't.
What it is
- A second set of eyes for the first QA/QC pass
- A way to find missing references, mismatched values, and broken load paths quickly
- Open about its method: read the skills, disagree with them, tell me
- Careful with your drawings: they're sent to Claude for the review and not stored. A copy of the findings text (never the drawings) comes to me so I can improve it, unless you untick that box
What it isn't
- Engineering advice, a stamp, or a substitute for the engineer of record or plan check
- A capacity check: it doesn't run calculations
- Always right: it can miss things and it can flag things that are fine
- A place for confidential drawings: only upload sets you're allowed to share with a third-party AI service
Free to try: one review per person per week while I cover the cost, on PDFs up to 100 MB, with up to 30 drawing sheets, 150 spec pages, or 50 calc pages per review. If you have your own Anthropic API key, you can paste it in to run more.
Try it on a set and tell me where it's wrong.
The most useful thing you can send me is a miss: a value it misread, a finding that isn't real, or a gap it should have caught. One round of markups on a single review became a dozen new rules.
Rather walk through it together? Email me and I'll run a set with you in 15 minutes.