The ten most useful ChatGPT prompts for a small domestic building firm cover scope notes, the quote cover email, quote follow-ups, price objections, stage-payment requests, overdue chasers, variations, delay notices, weekly updates and handover. Save them in one ChatGPT Project with your terms and sample emails, and keep every number and date your own.
Prompts only help if the output sounds like you and the facts are right. ChatGPT can invent prices, dates and promises when it is not given them, so every prompt below takes your facts in square brackets and ends with a CHECK BEFORE SENDING list. The Project holds your terms, your standard exclusions and three real emails, so the drafts come back in your voice instead of a brochure's.
One change since older advice: OpenAI no longer lets you create custom GPTs, and the ones already built switch off on 11 December 2026. A ChatGPT Project is the replacement for this job, and Projects work on every plan, including Free.
This pack suits a firm doing domestic work for homeowners, such as extensions, lofts, kitchens and bathrooms, where the client is a person in their own home and every email is read at the kitchen table. The general contractor prompt pack covers bid screening, subcontractor packages and site reports instead.
Set up one Project before you write a single prompt
Create a Project called something like Office, add the instructions below, and upload up to five files. According to OpenAI's Projects help page, a project's instructions take precedence over your account-wide custom instructions and only apply inside that project. A Free account holds five files per project, Go and Plus 25, and Pro and Business 40, and you can upload 10 at a time.
You are the office assistant for [firm name], a small building firm doing domestic work: extensions, lofts, kitchens and bathrooms for homeowners. Write as [your name], in the voice of the emails in voice-samples.txt: friendly, plain, direct, short paragraphs, no jargon the client has not used first.
Rules:
1. Never invent prices, dates, product names, measurements or promises. If something is missing, leave it in [square brackets].
2. After every draft, add a short list headed CHECK BEFORE SENDING with every figure, date and commitment in the draft, and anything missing.
3. Never admit fault, blame a named person or firm, or threaten legal action. If a message could turn into a dispute, say so at the end and stop.
4. Keep emails under 180 words unless I ask for more. End with one clear next step.
5. Do not mention that you are an AI.
6. Use only terms.txt, rates.txt and exclusions.txt for terms and prices. Do not add clauses.The five files are small and plain: terms.txt (deposit, stage payments, validity, how variations are agreed and what you can do if payment stops); rates.txt (day rates and standard provisional sums, not your margins); exclusions.txt (your standard exclusions); voice-samples.txt (three real emails with names removed, one friendly, one firm, one explaining a delay); and prompts.txt (the ten prompts below, so you open one file and copy).
Keep bank details, client surnames, full addresses and entry codes out of every file and every prompt. Use first names and job codes. If a prompt needs a client's message, paste the message with the surname and address deleted.
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Buy nowOne extension from quote to handover: where each prompt fires
The prompts make more sense laid against one job. Take a kitchen extension quoted at $62,400, on a 10% deposit and five stage payments. The same job appears in several of the sample emails below.
| Stage | Share | Amount | Prompts that fire |
|---|---|---|---|
| Site visit and quote | $62,400 quoted | 1 scope, 2 cover email, 3 follow-ups, 4 price objection | |
| Deposit on acceptance | 10% | $6,240 | 5 payment request |
| Stage 1: foundations and slab | 20% | $12,480 | 5, plus 9 each Friday |
| Stage 2: structure watertight | 25% | $15,600 | 5, and 6 if payment is late |
| Stage 3: first fix and plaster | 20% | $12,480, plus a $1,350 variation | 7 variation, 8 if the doors slip, 5 |
| Stage 4: kitchen and second fix | 15% | $9,360 | 5, 9 |
| Completion | 10% | $6,240 | 10 handover |
The shares add up to $62,400, and the underfloor heating variation takes the contract to $63,750. Stage 3 shows what the CHECK BEFORE SENDING list is for. If the variation goes on that stage invoice, the email should say $12,480 plus $1,350, which is $13,830. A draft that says $12,480 invites a question, and one that says $14,830 overbills the client by $1,000. Ask the AI to show that sum in its check list, then confirm it against the invoice itself.
If you set up only three prompts this week, make them the stage-payment request (5), the Friday update (9) and the follow-up pair (3). They are the messages most firms write again and again, and each follows a pattern that a prompt can hold.
Quotes that win the work
1. Scope and exclusions from site notes
Use this after the site visit, before you price anything. It turns scribbled notes into a scope the homeowner can follow and a provisional-sums table that stops arguments later.
Turn these site notes into a scope of works for a quote. Output:
1. A scope of 5 to 8 plain-English lines a homeowner can follow.
2. Inclusions as a bulleted list.
3. Exclusions as a bulleted list: use exclusions.txt plus anything the notes imply.
4. Provisional sums as a table: item, what it covers, what would change the figure. Leave amounts as [ ].
5. CHECK BEFORE SENDING: anything the notes leave unclear.
Do not price anything and do not add work the notes do not mention.
Site notes:
[paste notes]Say the notes read: first-floor bathroom, 2.4 by 1.9 m; strip out suite and tiles; pipes may need moving for the new shower; client buys tiles and suite; extractor fan wanted, none there now; ceiling needs a skim. A typical reply (illustrative):
Scope: strip out the existing suite and tiles; adjust pipework for the new shower as needed; fit the client's shower, toilet and basin; tile the floor and walls with the client's tiles; supply and fit an extractor fan, with the electrical connection by a qualified electrician; skim and paint the ceiling; clean and remove waste. Exclusions: supply of tiles and suite; decoration outside the bathroom; repairs to floor structure or hidden defects. Provisional sums: pipework alterations [ ]; fan and electrical work [ ]; floor repairs if found [ ]. Check before sending: who disposes of the old suite, whether the fan position is agreed, and when the tiles arrive.
A typical first draft says "new plumbing throughout" where the notes said pipes may move. That overstatement is why the last line of the prompt bans added work and why pipework sits in the provisional sums. For a priced version of the whole quote, see the worked example of a ChatGPT-written builder's quote.
2. The cover email that explains the price
A quote attached to a blank email gets read as a number. This prompt makes the email carry the three things the client needs to understand it.
Write the email that goes with the attached quote for [job in one line]. Total [amount], valid for [days] days. Include: one sentence on what is covered; the three things most likely to change the final price, using the provisional sums below; the earliest start date [date] and how long the job takes [weeks]; how to accept (reply "accepted" and I will send the deposit invoice); what happens next. Do not repeat the whole quote and do not use the word "guarantee". Warm but businesslike. Under 170 words.
Provisional sums:
[paste]Hi [first name], thanks for having me round to look at the kitchen extension. The attached quote of $62,400 covers the build, the finishes you chose and the electrics and plumbing for the new kitchen, and it is valid until [date]. Three things could move the price: groundworks, where the foundation depth is a provisional $4,200 until we dig; the bifold doors, held at an allowance of $5,800 until you choose; and the tiling, at an allowance of $2,400. If you would like to go ahead, reply "accepted" and I'll send the deposit invoice. The earliest start is 12 January and the build runs about 14 weeks. [your name]
Without the ban, a typical draft says "we guarantee the price will not change", which contradicts the provisional sums in the same email. Banning the word closes that gap, and the CHECK BEFORE SENDING list shows each dollar figure so you can match it to the quote in a minute.
3. A follow-up that does not nag
A quote that goes quiet is not a no, only a pending decision. Two short messages, a week apart, are easier to answer than one long one, provided neither invents pressure.
Write two follow-ups for a quote sent on [date] for [job]. Message 1 (day 5): check they received it and offer a call to go through any line. Message 2 (day 12): ask whether they have decided either way, say the price is held until [date], and make it easy to say no. No pressure, no invented deadlines, no "just checking in". Each under 70 words, in the voice of voice-samples.txt.Message 1. Hi [first name], did the loft conversion quote reach you OK? Happy to talk through any line, even five minutes by phone. [your name]
Message 2. Hi [first name], I'm holding the price until [date], so I wanted to ask whether you have decided either way. A no is completely fine and helps me plan the diary. [your name]
Watch for a line such as "we only have two start slots left", which models add because it sounds persuasive. Delete it unless your diary says so. Diary-based scarcity is honest; invented scarcity is not, and clients remember.
4. A reply to "another builder is cheaper"
This is a hard email to write well in the moment, because it is tempting either to drop the price at once or to snipe at a rival. The prompt rules out both and moves the conversation to what each quote includes.
A client says another builder quoted less for the same job. Their message is below. Draft a reply that thanks them; does not criticise the other builder; asks to see the other quote so we can compare it line by line; lists the items in my quote that cheaper quotes often leave out, using exclusions.txt; and offers two options: keep my scope and price, or a reduced scope where I will list the lines that could come out [I will add the figures]. Never offer a discount. Under 200 words.
Client message:
[paste]Hi [first name], thank you for telling me, and for being open about it. I'd be glad to compare the two line by line if you are happy to send the other quote. Quotes often differ in what they leave out, so check whether the other one includes waste removal, making good after the electrician, scaffold hire and finishing paint. There are two ways forward: I keep the scope and price as quoted, or we reduce the scope and I send you a list of the lines that could come out, with the effect on the price. Which would you prefer? [your name]
Delete any line that sounds like criticism of another firm ("some builders cut corners" is the usual one), and fill in the reduced-scope figures yourself. The reply works because it is calm and asks for information. If you do reduce scope, send the revised quote as a new version, not an edit of the old one.
Getting paid: stage requests, overdue chasers and variations
5. The stage-payment request
A payment request that says what was finished at this stage is easier for a client to approve than a bare invoice, because they can see what the money covers.
Write the email that goes with invoice [number] for the [stage name] stage of [job]. Stage completed [date], amount [amount], due [date]; payment details are on the invoice. Say what was completed in 3 or 4 specific bullet points from the notes below, what happens next and when, and nothing else. Friendly and brief. Under 140 words.
Stage notes:
[paste]Hi [first name], the roof is on and the extension is watertight, which completes stage 2. Invoice 0147 for $15,600 is attached and due on [date]. This stage covered the walls up to roof level, the roof structure and covering, and the windows, with the bifold opening boarded until the doors arrive. First-fix electrics and plumbing have started and belong to the next stage, with plastering from [date]. If anything on the invoice is unclear, ring me. [your name]
Read the "what was completed" line against your own notes. Models tidy: "first-fix plumbing started" can become "plumbing complete", and a client who reads "complete" will expect to see no more pipes. The builder invoice template for stage payments covers how to set the stages themselves.
6. A three-step overdue sequence
Chasing late payment is where tone slips and where a wrong sentence causes the most harm. Draft all three messages at once, calmly, then send them one at a time.
Invoice [number] for [amount] was due on [date] and is [n] days overdue. Write three messages: (1) a friendly reminder for today that assumes an oversight; (2) a firmer message for day [x] asking for payment or a date they will pay; (3) a final message for day [y] that states the next step my terms allow (clause pasted below), with no threats. Each under 110 words, factual, with the invoice number and a payment link placeholder. After the three messages, list what I should check with an adviser before sending message 3.
My terms, relevant clause:
[paste]Message 1. Hi [first name], a quick one: invoice 0147 for $15,600 was due on [date] and I can't see it has come through. It may have crossed with your payment. The details are on the invoice [payment link]. If anything is holding it up, let me know. [your name]
Message 2. Hi [first name], following up on invoice 0147 ($15,600, due [date], now [x] days overdue). Could you pay it by [date], or tell me when to expect payment? I'd like to keep the plastering on schedule, so I would rather sort this out this week. [your name]
Message 3 cites your own clause, for example that work pauses from a stated date while an invoice is unpaid. Two edits matter. Delete any interest rate or penalty the AI adds unless the same figure is in your signed terms, and delete any phrase such as "or we will take legal action". Have a solicitor read your payment terms and the pause-work clause once, and have anything that mentions legal steps checked before it is sent. The prompt's closing checklist is there to remind you.
7. The variation email that gets a yes before you start
Extras agreed on the doorstep become disputes at the final invoice. This prompt turns a verbal request into a written offer and makes the client's reply the trigger for starting.
The client has asked for extra work: [what they asked]. Draft an email that confirms in plain words what the extra work is, the price [amount], what it does to the programme [days], what it does not include, and that I will not start it until they reply "agreed" to this email. Offer one cheaper alternative if there is one [describe]. Then, separately, list the paperwork I should update (quote revision, programme, next invoice). Email under 170 words.Hi [first name], to confirm what we discussed: electric underfloor heating in the new kitchen floor, mat and thermostat supplied and fitted, for $1,350, which adds about two days to the programme. It does not include any change to the tiling already quoted or any upgrade to the existing electrics. I won't start it until you reply "agreed" to this email, as the mat must be ordered by [date]. A cheaper option is heating under the dining end only, for $780. [your name]
Paperwork list: revise the quote, adjust the programme by two days and add the line to the next stage invoice. If a draft says "we'll start on Monday", delete it, because the whole point is that nothing starts before the reply. The tutorial on how small builders price variations and change orders goes into the pricing side.
Keeping the client calm: delays, updates and handover
8. A delay notice without excuses
Bad news gets worse the longer it waits. Send it the day you know, with new dates marked as expectations.
Write a delay notice to the client. Cause: [what happened, factually]. What it affects: [tasks]. New expected dates: [dates, described as expected, not guaranteed]. What I am doing about it: [actions]. What I need from them and by when: [decision or access]. Honest and calm, no blame, no excuses, no over-apology. Under 150 words. Promise nothing I have not listed.Hi [first name], the manufacturer has delayed the bifold doors, and the new delivery date they have given us is [date], two weeks later than planned. That pushes back fitting the doors and the plastering that follows, so we now expect to finish around [date], though that depends on delivery. Meanwhile we are bringing forward the kitchen first fix so the site stays busy. I need your decision on the worktop by [date] to hold the programme. I'm sorry for the knock-on, and I'll update you the moment I hear anything. [your name]
The line to watch is "we will finish on [date] without fail". Dates in a delay notice are expectations, so the prompt says so, and so should the email.
9. The Friday update from site diary notes
A weekly email is a ten-minute job when the notes already exist, and it answers many of the questions a client would otherwise phone in. The prompt separates good news from risks so that problems cannot hide in a cheerful paragraph.
Turn my site diary notes into a Friday email to the client. Structure: done this week (3 to 5 plain-English bullets), next week, decisions I need from them with dates, anything that might affect cost or dates, and a one-line sign-off. Maximum 180 words. Include nothing that is not in the notes. If a note looks like a problem, put it under "might affect cost or dates" and do not soften it.
Diary notes:
[paste]Given notes such as "Mon-Tue roof timbers, felt and battens. Wed roofer found rot in existing fascia on old house, need decision on replacing. Thu windows delivered, one pane cracked, replacement five working days. Fri first fix started", a typical reply is:
Done this week: roof timbers, felt and battens completed; windows delivered; first-fix electrics started. Next week: roof tiling, window fitting apart from one pane, first-fix plumbing. Decision needed: whether to replace the rotten fascia section on the old house. I'll send a price on Monday, and I'd be grateful for your answer by Wednesday. Might affect cost or dates: the rotten fascia, which would be an extra cost, and one cracked pane whose replacement is five working days away, so one window may go in late. [your name]
Without the "do not soften it" line, the rotten fascia can become "a minor point to look at". The client should see the cost risk the same week you do.
10. Snagging and handover in one email
The handover email sets expectations for the last fortnight: when you will walk the house, how snags get closed, and when the final payment falls due. Getting those three dates in writing helps head off the usual end-of-job friction.
Write the handover email for [job]. Include: thanks (one sentence); the snag visit date [date]; that the snag list is attached, and what snagging means in plain words; how long we expect to close items [days]; what the client should do (list anything they notice by [date]); the final invoice amount [amount] and when it is due; care and warranty notes from my notes below; how to reach me about problems afterwards. Under 220 words.
Notes:
[paste]Hi [first name], thank you for trusting us with the kitchen and the extension. On [date] we'll walk the house together and list anything still to finish, which builders call snagging, and I've attached the list from our own inspection. We expect to close the items within [number] days. If you notice anything else, send it to me by [date] and I'll add it. The final invoice for $[ ] is attached and due on [date]. Care and warranty notes are below, taken from my notes. If anything goes wrong afterwards, ring or email me and I'll arrange a visit. [your name]
The risk here is a new promise. A model may add "a 12-month guarantee" or "free repairs for life" because handover emails often contain them. Your CHECK BEFORE SENDING list should show every commitment so that one you never made is easy to spot. The tutorial on client updates and snag lists for builders covers the list itself, and five customer messages for contractors adds shorter notes for the moments between these ten.
What to check before any of these emails goes out
| Check | What to look for | Typical AI slip |
|---|---|---|
| Numbers | Every amount matches the quote, invoice or variation | Rounds, swaps or invents a figure |
| Dates | Start, due and deadline dates match the diary | Adds a weekday you never gave it |
| Promises | No guarantee, deadline or free work you did not offer | Adds reassuring commitments |
| Blame | No person, supplier or rival is criticised | Explains a delay by blaming someone |
| Terms | Payment, pausing work and warranty wording match your signed terms | Adds clauses or an interest rate |
| Tone | Calm and factual, nothing you would not say to the client's face | Over-apologises or turns stern |
Read each email aloud before sending. If it does not sound like you, change it until it does, or add that email to voice-samples.txt so the next draft starts closer. Payment terms, pause-work clauses and anything that mentions legal steps deserve a solicitor's read once, after which the prompts only ever quote them.
Turning your best email into an eleventh prompt
The ten above are a start. The most useful prompts in your Project will be the ones you build from emails that already worked. Take a message that got a fast, friendly reply, remove the names, and ask:
Here is an email I sent that worked well. Write a prompt that would make you produce a similar email for a different job. List every fact I would need to supply as [square brackets], tell me what rules the prompt should include to keep it in my voice, and give me a CHECK BEFORE SENDING list for it.
[paste the email]A concrete eleventh is the decision chaser. Few things stall a job like a client who has not chosen tiles, a worktop or a door colour. Suppose your best message on this was short, gave the date the order must go in, and said what would happen to the programme if it slipped. The prompt the AI writes from it looks something like:
Write a message asking [first name] to decide [what, e.g. the worktop] by [date]. Say why that date matters (the supplier needs [number] weeks, so a later decision pushes [task] back by about [number] days), offer to meet or call if it helps, and include the two or three options with their prices [paste]. Friendly, no pressure beyond the real date. Under 100 words.A typical reply: "Hi [first name], could you let me know your choice of worktop by Thursday? The supplier needs three weeks, so a later decision would push the kitchen fit back by about four days. The two options are the laminate at $1,150 and the quartz at $3,400, both fitted. Happy to call or meet at the showroom if that helps. [your name]". Check the dates and the lead time against the supplier's own quote.
Test the new prompt on three real jobs before trusting it, then save it to prompts.txt. After a month, look at which drafts you rewrote heavily. Each rewrite points to a missing rule or a thin sample email, and adding it to the Project improves every later draft.
A Project like this will not run your office, and it should not. It drafts the emails that cost you evenings, keeps your terms and voice in one place, and hands every figure and promise back to you for a last look before it reaches a client.
Questions builders ask about ChatGPT prompts
Do I need a paid ChatGPT plan to keep these prompts in a Project?
No. Projects work on the Free plan with up to five files each, enough for your terms, rates, exclusions, voice samples and this prompt list. Go and Plus allow 25 files per project, and Pro and Business allow 40. Paid plans mainly add usage. Start free and upgrade only if you run into the limits.
Can I use Claude or Gemini instead of ChatGPT?
Yes, because the prompts are plain text. Claude's projects work in a similar way, with custom instructions and a knowledge base, and Free users can create up to five. Gemini Gems are becoming skills from November 2026, so check how your account describes them. The checking routine below does not depend on the tool.
How do I stop ChatGPT inventing prices and dates?
Never let it supply them. Every prompt here takes your figures in square brackets and ends with a CHECK BEFORE SENDING list, so you can compare each number and date with your quote, invoice and diary. Do any totals in a spreadsheet, not in the chat, and delete any promise you did not make.
Is it safe to paste client details into ChatGPT?
Paste only what the task needs: first names, job codes and the facts of the message. Keep out bank details, full addresses, alarm codes and photos with faces. ChatGPT Business does not train on your content by default, while personal plans have a model-improvement setting to review. You stay responsible for every email you send.
Further reads
- AI for Building Contractors: Chasing Subcontractors and Progress Updates — Chase subcontractors for progress and paperwork the same way.
- Can AI Produce Accurate Estimates for a Small Building Firm? — Check how accurate AI estimates can be before you rely on them.
- Best AI for Builders: Pick the First Job by Hours Lost and Risk — Pick the first AI job by hours lost and risk.
- General Contractor AI: Turn Site Messages Into Change Orders — Turn site messages into change orders.
- AI Receptionist for Builders: Take Calls While You Are on Site — Take calls while you are on site.
- AI Scheduling for Small Builders: Subcontractors and Deliveries — Schedule subcontractors and deliveries with AI help.
- Get More Leads as a Builder: A 30-Day Plan Drafted With AI — Plan 30 days of lead generation for a building firm.
- AI Assistant for Contractors: ChatGPT, Claude and Gemini on Real Jobs — One bathroom refit, three jobs: quote lines, a scope of works and a tricky client email, run the same way through ChatGPT, Claude and Gemini.
- Garage Conversion Leads: Qualify by Door Size, Floor and Planning With AI — A seven-question intake, a six-photo checklist and green, amber, red sorting that tells a garage conversion firm which enquiries deserve a survey visit.
- How to Price Building Work: Check Your Rates Against Past Jobs With AI — Compare quoted and actual cost line by line on past jobs, find what you underprice, and turn it into a rate sheet you test before quoting.
- Renovation Quote Template: Room-by-Room Scope Written With AI — A room-by-room renovation quote with stage grids, allowances and exclusions, plus prompts that draft clear wording from your survey notes.
- AI for Home Construction: Where It Helps a Builder, Plot to Handover — Seven build stages from enquiry to handover, with the job AI can take and the job that stays yours at each, plus which stage to try first.
- How Can AI Help My Construction Business? Five First Jobs to Try — Five first jobs for an owner-run construction firm, ranked by effort and payback, each with a starter prompt and a six-person worked example.
- AI Tools and AI Development: The Complete 2026 Guide — the AI hub, including every tutorial in the AI-for-business series.
Sources: OpenAI's help pages on Projects in ChatGPT and on file uploads; Anthropic's help article on Claude projects. Prices, dates and job details in the sample messages are illustrative.