Case study · Construction and engineering · Claude rollout
A civil engineering firm put its whole office on Claude, and every draft still waits for a person
A civil engineering, planning and survey firm of about fifteen people wanted to use Claude across the office without risking its project files. We set up the company workspace, wrote the rules Claude follows, and built the front office's first three jobs with the people who do them: weekly timesheets into the billing system, permit status across the agency portals, and responses to agency comment letters.
- Client
- A civil engineering, planning and survey firm in the United States
- Industry
- Civil engineering and land surveying
- Users
- Up to 15 staff: the owners, the front office, engineering and CAD, and survey
- What we built
- A Claude Team workspace in the firm's name, a company plugin, two personal plugins and three front office workflows
- Connected services
- Microsoft 365 for drafts and calendar entries, Sage Timeslips through its import file, 15 agency permit portals read only, and a private GitHub repository
- AI in the product
- Claude Team, with Claude in Chrome for the permit portals
- Status
- In pilot with the front office, November 2026
- 159 of 159timesheet slips matched on the first full weekly run
- 9 of 15agency permit portals read by Claude; a person keeps the other 6
- 48past comment letters turned into the firm's response format
- 17plugin releases, each reviewed as a pull request in the firm's own repository
These are figures from the pilot and from what was built and checked. No time savings are claimed yet.
The problem
The front office spent its week on work a computer could prepare. Staff emailed their timesheets in, and the office manager typed every line into Sage Timeslips, which has no API. The permitting coordinator opened city, county and state portals one at a time to see whether anything had changed on a permit. Every response to an agency comment letter started from an old letter that was copied and rewritten.
The owners wanted AI to take on that work, but they had good reasons to be careful. The firm's drawings and project files live on an office file server, and a single renamed or moved file inside a project folder can break the references between CAD drawings. The server's recycle bin does not catch a rename. Some people were already trying AI tools in their personal accounts, and the firm had no full-time IT staff to police any of it.
What we built
A workspace the firm owns.
The Claude Team workspace is in the firm's name and on its billing, with the owners as administrators. We hold no seat in it. The company plugin's master copy sits in a private GitHub repository the firm owns, so every version is saved and any change can be undone.
Rules Claude reads before every task.
The company plugin carries the firm's facts, its people and roles, a map of its server drives, its active projects and its ground rules. The first rule never bends: nothing is sent, submitted, filed, invoiced, paid or signed without a person. Claude declines every delete, saves new files instead of changing old ones, and connects one project folder at a time, never a whole drive. The owners and the front office each have rules for their own work, and the engineering and survey rules follow as those groups come on.
Weekly timesheets into the billing system.
Claude reads the week's timesheets and field crew sheets and builds one import file in the exact layout Timeslips expects. It lists anything that needs a decision, compares the billing system's export with what was sent, prepares a review file for the owners by project lead, and drafts reminders for late sheets. At the end of the pay period it prepares the payroll file for the bank. It never imports, never sets a billing rate and never puts pay rates or Social Security numbers in any file.
Permit status across the agency portals.
The permitting coordinator starts a permit check whenever it is needed. Claude reads each portal in the coordinator's own signed-in browser through Claude in Chrome, one record at a time and read only. It files every new agency document into the project's folder, updates one permit workbook and drafts one update email per project for the engineers. When a portal shows a captcha or a login page, it hands back to the coordinator. Six portals stay with a person, because of their terms, their logins or the way they are built.
Comment-letter responses in the firm's own format.
We studied 48 of the firm's past response letters, from 2020 to 2026, and wrote down their layout and wording. Claude files a new agency letter, quotes every comment in that layout, marks each one general or technical, and suggests an answer from the project files and the past letters. The permitting coordinator answers the general comments. Every technical answer stays highlighted until the project engineer edits it, and the coordinator uploads the finished response with its plans.
Personal plugins with a playbook the person owns.
The office manager and the permitting coordinator each have a personal plugin, shared only with them and the owners. Its core rules are locked. The way they like their output, such as extra columns, wording or the order of their week, lives in a playbook they change in plain English. Claude shows the before and after, waits for an OK, keeps a dated copy and can undo the last change.
Working sessions on real work.
Each workflow was built in working sessions with the person who does the job, on that week's real files, with a step-by-step card to follow. What came up in a session went into the next plugin release, and every release was reviewed before the firm's administrator installed it.
One week of timesheets, from the inbox to payroll
What the firm keeps control of
- Its own workspace. The Claude account, the billing and the administrator seats are the firm's.
- Its own files. Claude reaches the file server only through the Claude app on office PCs, with each person's own login. Nothing is installed on the server, and nothing new is opened to the internet.
- Its own releases. Every change to the plugins arrives as a pull request in the firm's repository, with release notes, and reaches staff only when the administrator installs it.
- Its own sign-off. Claude drafts. A person at the firm sends every email, files every document, approves every invoice and signs every letter.
Results
| Before | Now |
|---|---|
| Every timesheet line typed into the billing system by hand | One import file a week. The first full run matched 159 of 159 slips, with one import and no errors. |
| Each agency portal opened and checked one at a time | Claude reads 9 of the 15 portals on request, files new agency documents and updates one permit workbook. |
| Response letters started from an old letter each time | A first draft in the firm's own layout, built from 48 past letters, for the engineer to finish. |
| AI use left to personal accounts | Company work in the company workspace, under written ground rules. |
The permitting coordinator's verdict after the first full runs: the check works, the data is correct, and it is better organized than before.
Under the hood: how it is built and kept safe
Platform: Claude Team, with the Claude desktop app on each office PC and Claude in Chrome for the permit portals.
Plugins: plain-text skills, with no code, no scripts and no extra servers. On a Team plan a company plugin reaches every seat, so the two personal plugins are shared by upload with only the people who need them.
Microsoft 365: Claude's Microsoft 365 connector, used for drafts and calendar entries. Claude never sends an email; a person does.
Billing system: Sage Timeslips has no API, so Claude works only through its import and export files.
Security: a written security review sets out what Claude can reach, what it never does and how each release is checked.
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