Estimating & Vendor Outreach AI

The problem

Bid preparation was mostly typing. For every project the estimator copied plant and material lists off the plan sheets into a bid spreadsheet, set up the project's folders by hand, and emailed vendor after vendor for quotes. He put the plant-list step at a twenty-minute copy-and-paste each time, and wanted it down to a five-minute review.

What was built

Five n8n workflows, each doing one job so each could be tested on its own:

Project folders — a new deal in the CRM fires a webhook; the workflow checks it, creates the project's Drive folder with six standard subfolders and two template copies, and posts to Google Chat.
Plant-list OCR — the estimator submits a form with a screenshot of the plant schedule. The workflow finds the matching deal, sends the image to Gemini, which reads it into rows (quantity, botanical and common name, size, height, root, notes), and writes them into the project's copy of the quotation template.
Vendor quote requests — one workflow each for plants, materials and subcontracted work. Each reads the filled sheet, finds the matching vendors in the master vendor list, removes duplicates, drafts one Gmail quote request per vendor, logs it, and asks for approval in Google Chat.
A written guide for each workflow, so the team could run them without the builder.

The hard part

Change the input when the extraction is the problem. The first version read whole PDF plan sets, and it was not reliable enough to trust. Rather than keep tuning it, the input changed: the estimator screenshots just the plant schedule. A smaller, cleaner image made the extraction dependable, and the estimator still reviews every row.

Choose the model on the client's own drawings. GPT and Gemini were run on the same sample plan sheets and compared line by line; Gemini was chosen on that test.

One email per vendor, not one per line. A vendor who supplies five items should get one request, not five, so the outreach step groups and de-duplicates before drafting. In one test, eighteen sheet rows became five vendor emails. Nothing is sent until someone approves it in Google Chat.

What can be verified

Five workflows, built and tested with the estimator between December 2025 and January 2026
Demonstrated to the business owner and the estimator four times
GPT and Gemini compared on the same sample plan sheets before choosing Gemini
In a test, the vendor step reduced 18 sheet rows to 5 vendor emails
The plant-list and vendor workflows were switched on in February 2026

The workflows

Four n8n workflows shown together: two near-identical intake flows that take a Google Form submission, map it, read a supplier sheet, filter and de-duplicate, draft an email and log it before notifying a chat space; a fourth that fires when a quote is approved, merges supplier data, handles errors, de-duplicates, filters vendor emails, waits, then drafts to vendors and updates a dashboard row.

Four workflows behind one estimating process — two intake paths by material type, a longer orchestration across the top, and an approval path that drafts vendor outreach. The top strip is a longer workflow squeezed to the same width and is not legible at this resolution. Select the image to enlarge it — a graph this wide is not legible on a phone.

A plant schedule table from a landscape drawing: columns for quantity, key, botanical name, common name, root, size, height, mature height, spread and notes, grouped into canopy trees, understory trees, shrubs and groundcover.

The input: a screenshot of the plant schedule from a drawing, which is what the estimator uploads instead of the whole PDF. Select the image to enlarge it — a graph this wide is not legible on a phone.

An n8n node panel. On the left, the input from a "Standardize the Fields" step shows one plant read from the schedule: quantity 22, botanical name Quercus lyrata, common name Overcup Oak, root B&B, size 3 inch caliper, heights and spread. On the right, a Google Sheets node maps each field to a column of the bid sheet.

The output: the first row of that schedule after Gemini read it, mapped field by field into the bid sheet. Select the image to enlarge it — a graph this wide is not legible on a phone.

Two Gmail quote-request drafts side by side, each asking a different vendor for pricing and availability on its own item list with quantities, for example sod, seed and matting. The project name, the vendors' names and the signature are covered with solid boxes.

One draft per vendor, each with only the items that vendor supplies. Names and the project are covered. Select the image to enlarge it — a graph this wide is not legible on a phone.