What a BOQ actually needs to track on an interior design project

The BOQ starts as one spreadsheet. It ends as three: the one that was quoted, the one someone updated after a site visit, and the one finance is actually billing against. Nobody signed off on which is correct, because a spreadsheet doesn't have a concept of signing off.

A BOQ is a record, not a document

A bill of quantities on an interior design project needs to answer a specific question at any point in the job: what did we contract, what did we bill against it, and what changed since. A spreadsheet answers none of those unless someone maintains a second spreadsheet just to track the first one's history.

• The contracted version — frozen the day the contract is issued, never edited again
• Line items with quantity, unit rate, and the trade or room they belong to
• A payment schedule tied to those line items, not a separate number someone remembers
• A revision history where every change is a new version, not an overwrite
• An approval attached to each revision — who signed off, and when

Where the spreadsheet version breaks

It breaks the first time two people have the file open. It breaks worse the first time a client disputes a number and nobody can show what the BOQ said on the day the work was approved, because the only copy is the current one. By the time there's a dispute, the evidence has already been overwritten.

The fix isn't a better spreadsheet template. It's making the contracted BOQ a version that can't be edited, and making every change after that a new version with its own approval — the same way a signed contract doesn't get edited, it gets amended.

What this looks like in practice

Archgrid Studio issues a BOQ the same way it issues a contract: as a snapshot, hashed and frozen the day it's approved. A revision is a new version, not an edit to the old one. Costs are tracked against the version they were approved on, so "what did we agree to" and "what are we spending" never drift apart without someone noticing.