Reusable Context: Estimates That Do Not Start From Zero

Why estimates are the sharp edge

An estimate is the one document where a hallucinated number turns directly into lost money. If the model invents a per-square-foot rate and you send it, you have either underbid a job you must now perform at a loss, or overbid and lost it.

The mistake is asking the model to *know* your prices. It cannot. It can only apply prices you give it.

The rate sheet

Keep a short, current rate sheet alongside your business brief. It does not need to be sophisticated — it needs to be true and dated.

> RATE SHEET — Last verified: [date]

>

> House wash (soft wash, siding only) — $0.16–$0.22 / sq ft of wall area. Minimum $275.

> Driveway / flatwork — $0.18–$0.25 / sq ft. Minimum $150.

> Roof soft wash — $0.35–$0.55 / sq ft of roof area. Minimum $450. Steep pitch (>7:12) add 25%.

> Gutter cleaning — $1.75–$2.75 / linear ft. Two-story add 30%. Minimum $175.

> Window cleaning — $6–$11 per pane, interior + exterior. Minimum $200.

> Deck restoration (clean + brighten) — $1.10–$1.90 / sq ft. Stain is quoted separately.

>

> Adjusters. Heavy organic growth +15–30%. Difficult access / no driveway parking +10%. Repeat customer −5%. Bundled services (2+) −8% on the smaller service.

>

> Never quote below minimum. Below minimum the job does not cover drive time.

Ranges, not single numbers. The range is where your judgement lives, and it forces the model to hand the decision back to you.

The estimate prompt

> [paste business brief]

> [paste rate sheet]

>

> Draft an estimate from the details below. Rules:

> - Use ONLY rates from the rate sheet. Never invent a rate.

> - Where the sheet gives a range, show the range and state which end you'd expect and why.

> - Apply adjusters explicitly and name each one you applied.

> - List anything you needed and did not have, as "NEED TO CONFIRM".

> - Show the arithmetic so I can check it.

> - Do not send-format this; I want to review the numbers first.

>

> Job details: Two-story house, approx 2,400 sq ft of siding, moderate green growth on the north wall. Customer also wants gutters — approx 180 linear feet. Driveway parking is available. New customer. Requested for the week of the 14th.

Read it as a draft, always

Two things to check every single time:

1. The arithmetic. Ask for the working, then verify it. Multiplication errors happen and they are invisible in a nicely formatted quote.
2. The "NEED TO CONFIRM" list. This is the most valuable part of the output. It tells you what you cannot price yet — roof pitch, gutter guard presence, whether that "moderate growth" is actually moderate.

If the model did not produce a NEED-TO-CONFIRM list on a job it has never seen, be more suspicious, not less. A confident estimate from incomplete information is the failure mode.

Where the numbers live

Your rate sheet is a business document, not a chat message. Keep it somewhere you own — a document, a spreadsheet, your system's settings if it holds pricing. Paste it in; do not rely on the model remembering it from a conversation last Tuesday. Conversations end. Documents persist.

And when a rate changes, change it in the sheet, then re-date it. If you have ever quoted from memory and been wrong, you already understand why.

The pattern underneath

You are doing the same thing you did with the business brief: capturing verified state once, keeping it current, and starting from it every time. That is the whole of this capability. Everything else in this section is an application of it.

A quiet test of whether you have it: *if you stopped work today and came back in three weeks, what would you have to reconstruct from memory?* Whatever that is, write it down now.