# 14.9, How to price extras and variations without losing the customer
You protect yourself on extras by treating them like mini‑jobs: write them down, price them clearly, and get a "yes" before you lift a tool.
How to handle extras on domestic jobs
On domestic jobs, extras usually come from "while you're here…" or problems. The safest way to price them is:
Stop and define the change As soon as the customer asks for something new, pause and spell it out: what's changing, what's being added, what's being left out. In contract language this is a "variation" – any change to the original scope, quality, quantity or method of work.
Give a clear price before doing the extra You can price extras either:
- As a fixed amount for that extra item (e.g. "Extra radiator: £220 supplied and fitted"), or
- On your normal day/hourly rate if it's small or fuzzy, but still with an estimate and cap ("Likely half a day plus about £60 in materials").
Professional guidance for home extensions stresses that builders should always provide a quote for variations and get it agreed in writing before doing the work.
Confirm any programme impact Even on small jobs, say if it adds time. That avoids "you said you'd be finished Friday" arguments later.
Think: new scope = new price, in writing, agreed before you crack on.
Best way to communicate extra costs mid‑job
You don't need a fancy system; you do need a clear record.
Use simple written confirmations
Legal and project management guidance is crystal clear: variations should be in writing, so there's a record of the change, cost and timeline impact. For domestic jobs, a text, WhatsApp or email is usually enough as long as it's clear.
What your message should include
At minimum:
- What the extra is ("Add double socket by TV point")
- How much it will cost ("+£90 inc materials")
- Any time change ("adds about half a day")
- A clear "please confirm"
Example:
"Hi Sarah – as discussed, adding the extra double socket by the TV is £90 including materials and will add about half a day to the job. This is on top of the original quote. If you're happy, text back 'OK to go ahead' and I'll crack on."
Get a clear "yes" back
Construction law commentary shows courts care that the variation is evident from the written record. A simple "OK, go ahead" reply tied to your message is usually enough on small jobs.
For bigger domestic projects with a written contract, you can use a simple variation form, but the principle is the same: describe, price, sign off, then do.
Common disputes around extras – and how to dodge them
Typical rows on domestic jobs come from:
"I thought that was included" Lack of clear scope at the start is the biggest source of grief. Home extension advisors say budgets can blow by 20% when variations aren't documented and priced as you go.
Fix: good original quote (see S16) with clear inclusions/exclusions, then treat each extra as a separate, priced line.
Verbal agreements only Lawyers see endless disputes where extras were agreed "on the doorstep" but never written down; if the contract says variations must be written, verbal agreements can even be unenforceable.
Fix: nothing changes without a written note, even if it's "just a quick text".
Surprise final bills Customers get a nasty shock when extras are all dumped onto the final invoice with no warning.
Fix: tell them at the time what each extra will cost, then keep a simple running list you can show them before the final bill.
Time overruns blamed on you Extras nearly always add time, but if you don't say so, you get blamed for "running late".
Fix: when you price an extra, mention the time impact and confirm whether it moves the finish date.
If you always ask yourself "would this make sense to a stranger looking back in six months?", you're on the right track.
Standard approaches: what "formal" looks like in plain English
On big contracts you'll hear "variation order" or "change order" – just a written instruction that changes the job and the price.
Guidance for UK construction says the basics are:
- A short description of the change
- The extra cost (or credit if work is removed)
- Any time impact
- Agreement from both sides (signature or clear written acceptance)
On domestic jobs you don't need full QS forms, but you can copy the idea with:
- A simple Variation section in your quote/contract ("Any changes will be priced and agreed in writing before being carried out.")
- A one‑page variation template for bigger jobs, or just numbered text/email variations for smaller jobs ("Variation 3 – additional tiling to window reveals…").
Rule of thumb from the legal side: if you want to be sure of getting paid for extras, treat every change like a tiny contract of its own – written, priced, and clearly accepted.
What to do next
- Read: 14.8 – Materials: who supplies, who pays, where's the margin? (extras often involve extra materials too)
- Read: 2.5 – Variation orders: protecting yourself (the full legal picture on variations)
- Read: S16 – Writing your first quote (get your inclusions/exclusions right from the start)
- Read: 9.1 – When the customer changes their mind mid‑job
- Download: Variation confirmation email template
- Download: Variation log (CSV) – track every change on one sheet
- Download: Change of scope confirmation template
Sources (UK)
- UK construction law commentary – variation enforceability, written record requirements, court treatment of verbal vs written variations.
- Home extension and project management guides – budgets blowing by 20%+ when variations aren't documented; best practice on pricing changes before doing them.
- Contract guidance (JCT, NEC, domestic) – standard variation order formats and requirements.
- Consumer Rights Act 2015 – framework for domestic contracts, including changes to scope and price.
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