AI Excel Agent: From Prompt to Calculation Sheet

TL;DR: The AI Excel Agent builds complex, structured engineering spreadsheets (e.g., steel beam design) from plain English prompts, delivering working calculations compliant with codes like AISC 360-22 or ACI 318-19 in approximately three minutes. The resulting sheets feature highlighted input cells, load combinations, visible capacity calculations, and clear pass/fail checks documented with code references. A key capability is reading and modifying existing legacy spreadsheets, allowing users to automatically update code-dependent formulas, such as changing a calculation basis from AISC 360-16 to AISC 360-22.

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You need a steel beam design spreadsheet. The old way: dig through project folders, copy an old file, update cells one by one. Miss a reference somewhere. Spend an hour fixing it.

The new way: type what you need.

"Steel beam design, W-shape, 24ft span, dead load 80 psf, live load 100 psf, tributary width 10ft, AISC 360-22, deflection limit L/360"

Three minutes later you have a working spreadsheet. Load calculations, section selection, capacity checks, deflection verification. Change the span and everything recalculates.

This is what an Excel agent does. It builds engineering spreadsheets from plain English.

How It Works

You write a prompt describing your calculation. The agent builds a structured spreadsheet with:

• Input cells highlighted for easy editing
• Load combinations per the design code
• Capacity calculations with visible formulas
• Pass/fail checks with clear indicators
• Code references documenting each step

The more specific your prompt, the better the output.

Basic: "Concrete beam design, ACI 318-19"

Better: "Concrete beam design, rectangular section, 28ft span, f'c 4000 psi, Grade 60 rebar, dead load 1.5 kip/ft, live load 2.0 kip/ft, check flexure and shear per ACI 318-19"

The second prompt gives you something close to project-ready.

Working with Existing Spreadsheets

Excel agents also read and modify files you already have.

Got a legacy spreadsheet from an engineer who left? Upload it. The agent maps the structure, identifies inputs versus calculated cells, and explains the logic.

Need to update it? Tell the agent: "Change from AISC 360-16 to AISC 360-22" and it updates the code-dependent formulas while keeping your formatting.

Want to extend it? "Add a punching shear check for an 18-inch column" and the agent adds the new section linked to your existing inputs.

When This Helps

Preliminary design. Early phases need dozens of quick calculations. Generate spreadsheets fast, get answers, move on.

Standardizing firm calculations. Create prompts for standard calcs. Everyone generates from the same baseline.

Code updates. New code edition? The agent identifies and updates code-dependent formulas systematically.

Legacy maintenance. Understand and safely modify spreadsheets from past projects or departed engineers.

Connecting to Analysis Software

The real efficiency comes from integration. Using Stru AI with ETABS or SAP2000:

1. Run your structural analysis
2. Extract member forces via Stru AI
3. Excel agent generates design checks with extracted values
4. Model changes? Re-extract and spreadsheets update

No manual transcription. No version mismatch between model and calculations.

What Works and What Doesn't

Works well: Standard design checks, code-based calculations, consistent formatting, modifications to existing files.

Still needs you: Engineering judgment, unusual conditions, final verification, project-specific decisions.

The agent builds spreadsheets. You make decisions and verify results.

Getting Started

1. Pick a routine calculation. Generate it. Compare to your manual approach.

2. Be specific. Include design code edition, all loads, material properties, what checks you need.

3. Review like any engineering work. Verify inputs, trace formulas, check results make sense.

4. Refine your prompts. Over time you develop tested prompts that produce consistent results.

Try It

Pick a calculation you know well. Describe it in a prompt. Generate the spreadsheet. See if it fits your workflow.

Ready to try? Stru AI connects Excel agents to your ETABS and SAP2000 analysis workflow.