Save hours every week with the Contractor AI Operating System
A command center plus six connected jobs for estimates, change orders, customer comms, and project-manager paperwork (submittals, OAC minutes, pay apps) — drafted into your Gmail, Calendar, and Drive for your approval, with living trackers. Ambient lien-and-license guards built in. Every prompt included — 64 skills in all.
Installs as a Claude Cowork plugin — and every prompt is included as an HTML page you can use in ChatGPT, Gemini, or any AI. How to install → Prices are in USD; Gumroad applies fair local pricing at checkout in eligible countries.
Plumbers, electricians, HVAC techs and general contractors use Claude to turn site-visit notes into customer estimates, scopes of work, inspection reports and follow-up emails, so the paperwork gets done the same day instead of at the kitchen table that night. You bring the measurements, prices and code knowledge; Claude writes it up in plain language a homeowner can follow, and you check it before it goes out.
Below: one inspection report built from jobsite notes, the free Tradesperson plugin and its four commands, five more job documents, and straight answers on estimates, code references and customer data.
Worked example: an electrical inspection report from jobsite notes
You've just looked over a panel for a homeowner getting ready to sell. In Claude, type /inspection-report, pick it from the menu, then paste your notes:
Inspection report, residential electrical. 1978 single-family, owner getting ready to list.
Panel in garage: 200A Federal Pacific Stab-Lok, original to the house.
Double-tapped breakers on 3 circuits. Bedroom circuits: no AFCI protection.
Water heater: bonding jumper missing. Smoke alarms present, not tested.
Attic wiring not accessible (blown-in insulation). Rate severity. No pricing.Claude returns a structured draft (shortened here):
INSPECTION REPORT (DRAFT)
Property Type: Residential | Year Built: 1978 | Inspection Type: Electrical
Purpose: Pre-listing inspection requested by owner
FINDINGS SUMMARY
| # | Finding | Severity | Location | Action |
| 1 | Original Federal Pacific Stab-Lok panel | Major | Garage | Soon |
| 2 | Double-tapped breakers on 3 circuits | Major | Main panel | Soon |
| 3 | No AFCI protection on bedroom circuits | Minor | Bedrooms | Routine |
| 4 | Water heater bonding jumper missing | Major | Water heater | Soon |
FINDING #2: Double-tapped breakers
Description: Three breakers each have two conductors under one terminal. Unless the
breaker is listed for two conductors, this can loosen connections over time.
Code Reference: [verify section against the code edition your jurisdiction adopted]
Recommendation: Correct by a licensed electrician.
ITEMS NOT INSPECTED
Attic wiring: not accessible (blown-in insulation). Smoke alarms: present, not tested.What's left for you: confirm or change each severity rating, fill in code references from the edition your area actually enforces, attach your photos, and sign with your license number. The draft only rates what you wrote down; anything you didn't see shouldn't be in it.
The free Tradesperson plugin: four commands
The Tradesperson plugin is free. It adds these commands to Claude. Type the command and pick it from the menu; if you paste it, Claude treats it as plain text.
| Command | What it drafts |
|---|---|
/estimate |
A customer estimate with line items for labor, materials, permits and warranty |
/scope-of-work |
A scope-of-work proposal with phases, materials, timeline and payment schedule |
/inspection-report |
An inspection report with findings, severity, recommendations and photo references |
/customer-email |
Follow-ups, warranty details, maintenance reminders and estimate explanations |
Two skills switch on by themselves when they're relevant: Trade Documentation and Customer Relations.
To install it in the Claude desktop app: Customize → Plugins → Add → Add marketplace → Add from a repository, paste alexclowe/awesome-claude-cowork-plugins, click Sync, then click Add next to Tradesperson under Discover. Plugins need a paid Claude plan. In Claude Code: run /plugin marketplace add alexclowe/awesome-claude-cowork-plugins, then /plugin install tradesperson@awesome-claude-cowork-plugins. Full steps are on the plugin page.
What's paid: The free plugin is enough to start. If you want more, the Contractor AI Operating System ($19, one-time) adds a command center and six connected jobs for estimates, change orders, customer messages and project-manager paperwork. It drafts them into your Gmail, Calendar and Drive for your approval, keeps living trackers, and has built-in lien and license guards, with 64 skills in all.
Set up a Claude Project for your trade business
The key to getting consistently useful output from Claude is using Claude Projects. A Project lets you set custom instructions that persist across every conversation, so you are not re-explaining your business every time.
Step 1: Create a Trades Project. In Claude, click "Projects" and create one called something like "My Trades Business."
Step 2: Set your custom instructions. In the Project settings, add instructions like:
You are my trades business assistant. Here is my context:
<business-profile>
- Name: [Your Name], [Your Company]
- Trade: [Plumbing / Electrical / HVAC / Roofing / General Contracting / Painting / Landscaping]
- License number: [Your License Number and State]
- Service area: [City/Region]
- Typical jobs: [Residential service calls / Commercial installations / New construction / Remodels]
- Pricing model: [Flat rate / Time and materials / Per-unit pricing]
- Brand voice: [Straightforward and professional / Friendly and approachable]
</business-profile>
<rules>
- When writing estimates, always include a clear scope of work, material list, and payment terms.
- When writing customer communications, keep language simple and jargon-free.
- Always note that estimates are valid for 30 days and subject to on-site verification.
</rules>Step 3: Upload reference documents. Add your estimate templates, standard scope of work language, warranty information, or past proposals to the Project knowledge base. Claude will reference these when generating content.
Step 4: Start every session inside this Project. This ensures Claude always has your context loaded.
Five more job documents to hand Claude
1. Customer Estimates That Win Jobs
Give Claude your job notes and let it build a polished estimate that builds trust.
<task>Write a detailed estimate for a residential bathroom remodel.</task>
<context>
- Customer: homeowners Mark and Lisa, Austin, TX (no street address needed)
- Scope: full gut remodel of master bath (8x10), tub to walk-in shower (36x60), 60" double vanity, new toilet, tile floor/shower walls, 3 light fixtures, exhaust fan
- Mid-range materials, customer choosing tile/fixtures, 8-10 days labor, $85/hr 2-man crew
</context>
<instructions>
- Sections: demo, plumbing, electrical, tile/flooring, fixtures, cleanup
- Material and labor estimates per section, add permits line
- Payment terms: 50% deposit, 25% rough-in, 25% completion, valid 30 days
</instructions>
<avoid>Guaranteeing exact dates, including undiscussed work, or quoting customer-selected fixtures</avoid>2. Scope of Work Documents That Prevent Disputes
<task>Write a scope of work for an HVAC system replacement.</task>
<context>
- Customer: David, 2,200 sq ft home (1998)
- Current: 3-ton Carrier AC (R-22), 80% AFUE furnace. Ductwork acceptable, no replacement
- Proposed: 3-ton 16 SEER2 Trane AC, 96% AFUE variable-speed furnace, new thermostat
- Additional: new line set, disconnect, plenum ductwork modification. Permit required
</context>
<instructions>
- Clear inclusions and exclusions, equipment models and warranty terms
- Note old equipment removal, permit/inspection responsibilities
- Plain language, under 350 words
</instructions>
<avoid>Promising energy savings percentages, including undiscussed services, or excessive jargon</avoid>3. Inspection Reports That Document Everything
<task>Write an inspection report for a residential roof assessment.</task>
<context>
- Property: single-family home, Denver, CO, ~28 squares architectural asphalt (installed 2011)
- Shingles: granule loss south slope (60-70% life left), 3 cracked near west ridge
- Flashing: chimney step flashing lifting north side, counter flashing 1/4" gap
- Gutters: pulling from fascia at 2 locations, NW downspout disconnected
- Ventilation: ridge vent OK, 2/4 soffit vents blocked. Decking: no issues
</context>
<instructions>
- Organize by component, rate each (good/fair/needs attention/immediate repair)
- Include recommended repairs with priority, note what is in good shape
- Professional factual tone, under 400 words
</instructions>
<avoid>Estimating roof life in exact years, recommending unnecessary replacement, or including pricing</avoid>4. Customer Emails That Build Repeat Business
<task>Draft an email updating a customer on their kitchen remodel progress.</task>
<context>
- Customer: Jennifer, kitchen remodel (cabinets, countertops, backsplash, electrical)
- Good news: demo complete, rough plumbing/electrical passed inspection, cabinets arriving Thursday
- Issue: countertop fabrication 3 days behind, now Monday instead of Friday
- Overall still on track for April 11 completion
</context>
<instructions>
- Lead with good news, address delay honestly, reassure on completion date
- Explain this week's work, friendly professional tone, under 150 words
</instructions>
<avoid>Naming the fabricator, using technical jargon, or over-apologizing for a minor delay</avoid>5. Invoice Descriptions That Look Professional
<task>Write professional invoice line items for a completed electrical job.</task>
<context>
- Customer: Oakwood Dental Office, operatory build-out
- Work: 3x 20-amp circuits (dental chairs), 2x 30-amp circuits (compressor/vacuum), 6 LED recessed lights with dimmers, 4 duplex + 2 USB receptacles, LV conduit for data, 100A sub-panel
- All work permitted, passed final inspection
</context>
<instructions>
- Clear line items grouped by category (circuits, lighting, receptacles, panel, permits)
- Include quantities, concise but specific enough for customer understanding
</instructions>
<avoid>Hourly rate breakdowns (flat-rate job), NEC references, or vague combined line items</avoid>Prompting tips for estimates and job paperwork
1. Always specify the trade and job type. "Write for a residential plumbing service call" produces very different output than "write for a commercial HVAC installation." Tell Claude your trade and the context.
2. Include material specifics. Brand names, model numbers, and material grades make estimates and scope documents more credible and accurate.
3. Keep language customer-friendly. Add "Write so a homeowner with no trade knowledge can understand" to any customer-facing prompt. Claude will translate technical details into plain English.
4. Upload your best past estimates. Paste a previous estimate you are proud of and say "Match this format and tone." Claude adapts to your style quickly.
5. Mention your licensing and service area. This helps Claude include appropriate permit references and avoid suggesting work outside your scope of practice.
6. Use Claude to draft, then verify on-site. The best workflow is to generate the draft from your notes, then review it against what you actually saw at the job site before sending to the customer.
Can Claude write estimates for contractors?
Yes. Give Claude your site notes, quantities, material choices and labor rate, and it lays them out as a line-item estimate with scope, permits, payment terms and an expiry date. It doesn't know your costs or what you charge, so every number in the estimate has to come from you, and you check the totals before you send it.
Does Claude know the building, electrical and plumbing codes?
Only roughly, so don't rely on it for code. Claude can name code sections that are likely relevant, but it can be wrong, quote an edition your area hasn't adopted, or miss local amendments. Treat every code reference in a draft as a lead to check against the code your jurisdiction enforces; the inspector's reading is what counts.
Should an AI-written estimate promise a finish date?
No. Weather, inspections, material lead times and other trades can all move a schedule, and a draft can sound more certain than you mean to be. Ask Claude to write "estimated completion" rather than a guaranteed date, and read the payment and timeline sections closely before the customer signs.
Is it safe to put customer information into Claude?
Keep it to what the document needs: a first name, the town, and a general description of the property and the job. Leave out card and bank details, gate or alarm codes, and anything else you wouldn't write on a job board in the shop.
You can review how your Claude plan handles your chats in Anthropic's Privacy Center.
Is Claude or ChatGPT better for contractors?
Either one can turn your notes into an estimate or a customer email. The bigger difference is workflow: on the Claude side, the Tradesperson plugin gives you fixed commands with the same estimate and report layout every time.
We compare the two side by side in ChatGPT vs Claude for the trades.
Related guides and tools
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Get my free setupContractor AI Operating System
A command center plus six connected jobs for estimates, change orders, customer comms, and project-manager paperwork (submittals, OAC minutes, pay apps) — drafted into your Gmail, Calendar, and Drive for your approval, with living trackers. Ambient lien-and-license guards built in. Every prompt included — 64 skills in all.
Get the Operating System for $19Installs as a Claude Cowork plugin — and every prompt is included as an HTML page you can use in ChatGPT, Gemini, or any AI. How to install → Prices are in USD; Gumroad applies fair local pricing at checkout in eligible countries.