The Estimate

By the end of this session, you will have a professional estimate — itemized scope, exclusions, pricing with shown math, and your state’s required provisions — generated from a two-sentence job description and ready to review, adjust, and send.

What this session builds

The estimate prompt takes your business profile and a plain-language job description — typed or voice-dictated — and produces a formatted estimate document with:

• Your business header and license information
• Itemized scope of work
• Explicit exclusions (what is not included)
• Line-item pricing with shown math
• A material cost escalation clause
• State-specific disclosures for California, Texas, Florida, New York, and Pennsylvania
• Customer acknowledgment with signature lines

If your state is not one of those five, the prompt applies a common-denominator fallback: written change order requirements and a redirect to your state contractor licensing board. Check your state’s specific provisions before relying on the fallback.

Why the estimate matters more than you think

An estimate is not a quote and not a contract — but the legal distinction is about substance, not labels. What matters is what the document commits you to, not what you call it. A document labeled “estimate” that includes specific terms, a signature line, and language like “accepted and agreed” may function as a binding contract in court, regardless of the word at the top. The documentation standards research across multiple jurisdictions confirms this: courts look at what was promised and what both parties understood, not at the header.

This is why the prompt builds scope exclusions into every estimate. Stating what is not included is as important as stating what is. A homeowner who assumes the $2,800 water heater replacement includes drywall repair will dispute the final bill when it does not. An estimate that says “drywall repair not included” prevents that dispute before it starts.

Material costs have risen approximately 40% cumulatively since 2020, according to Contractor Accelerator’s tracking. Most residential trade estimates lack a price escalation clause — because it does not occur to the tradesperson to include one, or they do not know how to word it. The prompt adds one automatically: if material costs change significantly before work begins, pricing may be adjusted with written notice. One sentence that can save you thousands on a large job where the customer delays the start date.

Step 1: Start a new conversation

Open Claude, ChatGPT, or Gemini. Start a new conversation — do not reuse an old one.

If you set up a Claude Project, Custom GPT, or Gemini Gem in Session 1, open that instead. Your business profile is already loaded, and you can skip Step 3.

Step 2: Paste the estimate prompt

Copy the entire prompt below and paste it as your first message. Send it.

Step 3: Paste your business profile

The AI will confirm it has the prompt and ask for your profile. Paste the business profile you saved in Session 1.

If you do not have one yet, here is the minimum the prompt needs to work:

===== BUSINESS PROFILE =====
Business Name: [your business]
Owner/Contact: [your name]
Trade: [your trade]
State: [your state]
Standard Rate: [your hourly rate]
Payment Terms: [when you expect payment]
License/Registration: [your license number]
===== END BUSINESS PROFILE =====

The more complete your profile, the better the estimate. Rate, material markup, deposit requirements, insurance, warranty terms — all of these flow into the document automatically once they are in your profile.

Step 4: Describe the job

The AI will ask you to describe the job. You need five things:

1. Customer name
2. Job site address (city and state at minimum)
3. What the job is
4. Specific materials or brands, if any
5. Timeline, if relevant

You can type this out or use voice dictation — the built-in speech-to-text on your phone. Tap the microphone icon on your keyboard and talk. It does not need to be polished. The AI will ask follow-up questions if anything is unclear.

Here is what a voice-dictated job description might sound like:

“Water heater replacement for Sarah Chen at 4521 Oakmont Drive in Arlington. The existing unit is a 40-gallon natural gas, it’s in the garage. She wants a 50-gallon Rheem. I’ll need to run a new gas flex line and upgrade the T&P discharge. Probably four hours on site.”

That is enough. The prompt handles the formatting.

Step 5: Review every number

This is not optional. This is the step that separates a useful tool from a liability.

Research published in Nature (2025) confirms what anyone who has used a calculator app already suspects: AI is not reliable at arithmetic. Tool-augmented models produce 5.5 to 13 times fewer math errors, but the consumer chat interfaces you are using do not have those tool integrations. The AI will show its math — “3 hours x $95/hr = $285” — but you need to verify that 3 times 95 actually equals 285. It usually does. Sometimes it does not.

Beck et al. (2025), in a peer-reviewed experiment with 2,784 participants, found that professional-looking AI output reduces critical scrutiny. Conceptual errors were caught only 31% of the time, compared to 82% for spelling errors. The clean formatting makes the document feel more trustworthy than it is. You know what a water heater installation actually costs. Trust that knowledge over the document’s formatting.

Check these before you send anything:

• Every line item total (quantity times rate)
• The subtotal (sum of all line items)
• Any tax calculations
• The final total
• Material costs (are they current? do they match what your supplier charges?)
• Labor hours (does this match your actual time estimate for the job?)

The AI did not calculate your estimate. It predicted what an estimate might look like. The difference matters.

Step 6: Modify if needed

If something is wrong — a price, a scope description, a missing exclusion — tell the AI in plain language. “Change the labor to 5 hours.” “Add disposal of the old unit at $75.” “Remove the T&P discharge line item.” The AI will regenerate the estimate with your changes.

You can go back and forth as many times as you need. Each revision produces a new complete document.

Step 7: Download and send

On Claude, the estimate appears as an Artifact — a separate document panel with a copy button and download option. On ChatGPT, it renders in Canvas. On Gemini or other platforms, it appears between ===== BEGIN ESTIMATE ===== and ===== END ESTIMATE ===== markers — copy everything between those markers.

However your platform presents it, the result is the same: a complete, formatted estimate ready to send. Email it, text it, print it. The document is yours. The AI does not store it, track it, or send it for you.

Step 8: Save locally

Save a copy to your phone or computer. A note, a text file, an email to yourself — the same method you used for your business profile in Session 1. You will need this estimate if the customer requests a change order (Session 3) or if you need to generate the final invoice (Session 4).

Level Up: Save the estimate prompt for next time

If you set up a Claude Project, Custom GPT, or Gemini Gem in Session 1, add this estimate prompt alongside your business profile. Same project, same profile — the estimate prompt becomes a second tool in the same workshop.

Claude: Open your existing Project. Add the estimate prompt as project instructions alongside your business profile. Every conversation you start in that Project already has both loaded — no pasting.

ChatGPT: Create a Custom GPT with the estimate prompt as its instructions and your business profile as a knowledge file. Or keep one GPT for all document types and paste the relevant prompt at the start of each conversation.

Gemini: Add the estimate prompt to your existing Gem’s instructions alongside your profile.

The goal: the only thing you type (or say) is the job description. The prompt and the profile are already there. You open the app, describe the job, and the estimate appears.

Sample output

Here is what the estimate prompt produces using the Garrison Plumbing profile (Texas) and the water heater replacement job described above. On Claude, this appears as a formatted document in an Artifact panel. What you see below is the document content.

Notice what the prompt did automatically: it pulled Mike’s rate, markup, payment terms, license number, and warranty from his business profile. It added mandatory scope exclusions — things Sarah might assume are included. It showed the math on every line item so Mike can verify each one. And it applied the Texas Prompt Payment Act provision without Mike having to remember it exists.

Mike still needs to check every number. Is $780 the right wholesale cost for that Rheem unit from his supplier? Is four hours realistic for this job, or does the garage layout make it a five-hour job? Does he want to include disposal at $75, or does he typically charge more? The document is a draft. Mike’s trade knowledge makes it an estimate.

Voice input

You do not need to type the job description. Every phone has built-in speech-to-text — tap the microphone on your keyboard and talk.

Voice dictation works well for this because the prompt is designed to handle rough input. You can say “uh, it’s a 50 gallon Rheem, natural gas, she’s got the old one in the garage, I think four hours” and the AI will parse that into a structured job description. If it needs clarification — “Did you say 40-gallon or 50-gallon?” — it will ask before generating.

The baseline speech-to-text on iOS and Android is accurate enough for job descriptions in a quiet environment. On a loud job site, find a quieter spot — inside the truck, around the corner. Construction site noise degrades accuracy significantly, and a garbled job description produces a garbled estimate.

What happens in your state

The prompt encodes state-specific provisions for five states. Here is what gets added automatically:

California: Written contract required over $500 (BPC §7159). Down payment capped at $1,000 or 10%, whichever is less. Three-day cancellation notice with specific language. CSLB contact information and license number.

Texas: Payment due within 35 days (Prompt Payment Act). Three-day cancellation notice for home solicitation. License number for licensed trades.

Florida: Written contract required over $2,500 (Chapter 489). Payment due within 14 days (Prompt Payment Act). Homeowner Construction Recovery Fund notice. License number.

New York: Written contract required over $500 (GBL §771). Three-day cancellation. All changes in writing, signed by both parties. Registration number.

Pennsylvania: Written contract required over $500 (HICPA). Deposit capped at one-third of contract price. Three-day cancellation. Registration number and liability insurance reference.

All other states: The prompt applies a common-denominator standard — written change orders required, with a redirect to your state licensing board. This is a safe default, not a substitute for knowing your state’s rules. If you are in a state not listed above, verify your requirements before relying on the prompt’s output.

These provisions are encoded from primary statutes. They are not generated by the AI, and the AI is instructed not to add its own legal interpretation. That said, statutes change. The provisions reflect law as of March 2026. If you are reading this later, verify that your state’s thresholds and requirements have not changed.

This is not legal advice. It is a document generation tool that applies known requirements. For questions about how the law applies to your specific situation, consult an attorney in your state.

The estimate-quote-contract distinction

Trade professionals often use “estimate,” “quote,” and “bid” interchangeably. The law does not.

An estimate is a good-faith projection of cost. It communicates what the job will probably cost, not what it will definitely cost. A quote is a fixed price — the customer pays that amount and no more, regardless of what the job actually costs. A contract is a binding agreement with specific terms, obligations, and remedies.

The distinction matters because of how homeowners understand these documents. Research from Angi and FreshBooks indicates that many homeowners treat an “estimate” as a binding price commitment. When the final invoice exceeds the estimate, they see it as overcharging — even when the scope changed, the materials cost more, or additional work was required.

The estimate prompt addresses this in two ways. First, it includes scope exclusions — making explicit what the estimate does not cover. Second, it includes the material escalation clause — giving you written grounds to adjust if material costs move between the estimate date and the job date. Both are protective language that many handwritten estimates lack.

The language in the document is designed to be clear to the homeowner without being legalistic. The customer acknowledgment section says “agrees to the scope, pricing, and terms described above” — which establishes mutual understanding without turning an estimate into a contract. If you need a binding contract, that is a different document with different requirements. The estimate is the starting point.

What you built

You described a job in plain language — a couple of sentences, typed or spoken — and produced a professional estimate with itemized scope, exclusions, pricing with shown math, and your state’s required provisions. A fraction of the time it takes to write one by hand.

The estimate is a starting document. Your trade knowledge makes it accurate. Your review makes it trustworthy. The AI handled the formatting and the compliance language so you did not have to remember it.

Save the estimate. You will need it for Session 3, where a customer asks “while you’re here, could you also…” and you turn that into a documented change order before you put your phone down.

Get back to your craft.