How to record building variations before you do the extra work

By James Daly, Founder, Oi Guvnor · Updated 2026-10-09

"While you're here, could you just…" is how a lot of small builders lose money. The extra gets done, nobody writes it down, and by the final invoice the client remembers it as included. The fix is boring but it works: record every change, price it, and get it approved before you start.

What counts as a variation

A variation is any change to the agreed scope, materials, timing or conditions. Typical examples on small jobs:

The client asks for an extra task — another socket, a shelf, a wider opening
The client changes a material or finish after you've priced it
Something hidden is found once opened up — rotten timber, no lintel, old wiring
Work is omitted, which should reduce the price
Access or timing changes that add time or cost

The four-step routine

If something is urgent or unsafe and can't wait, make it safe, record what you found and what you did, and tell the client the same day. Don't let the urgency become a reason the extra never gets written down.

Record it: what changed, where, why, who asked and when
Photograph it: especially anything found when opening up
Price it: labour, materials and any time impact, separately
Get it approved in writing before doing the work — a reply by message or email is far better than a nod

What a variation record should show

Illustrative example — fictional job, prices left for you to fill in

Variation V3 — [site address]
Raised: [date], by [client name] on site
Change: add a double socket on the kitchen island, not in original scope
Reason: client request
Labour: [£] · Materials: [£] · Total: [£]
Time impact: half a day, no change to completion date
Status: awaiting client approval — not started
Photos: 2 attached

Keep a simple register

Number every variation in order and keep them in one list for the job: reference, description, price, status (raised, approved, rejected, done, invoiced). It turns the final account from a memory test into a quick check. It also shows the client, in one place, why the final figure differs from the quote.

Be honest about status. A variation you've recorded is not approved until the client says so, and an approved one isn't paid until it's invoiced and settled.

Handle omissions the same way

If the client drops something from the scope, record it as a negative variation with its value. Clients notice when credits are handled as carefully as extras, and it makes the extras easier to agree.

Where Oi Guvnor fits

In Oi Guvnor you can record a variation by voice or text, attach photos, price it and send it to the client for approval. Recording it doesn't mean the client has approved it, and the app shows the status separately. The live project page shows a variation register from a real job in progress.

This guide describes common good practice. It isn't legal, tax or contractual advice — check anything specific with a qualified adviser.