Disrespective:
You have the right to ask for a cost breakdown to indicate where all of the costs, including the extra ones were incurred.
If he decided he needed to use a more expensive paint than in the original quote, or painted the hallway when that wasn't in the quote, then he needs to have this value priced separately as extra work over and above the quote.
Without a cost breakdown it's hard to know where the price increase happened, and thus why.
No extra work, it just took more time/effort than he allowed for in his estimate. He said he allowed for a partial strip and had to do a full strip, but the language he used indicates that the quote includes up to and including a full strip. Relevant quote lines are:
- wooden window surround stripped back to bare wood where necessary
- All other areas scraped and sanded thoroughly
That to me covers a full strip.
There's also the issue that he has no evidence that a full strip was done, and I know for a fact that he didn't fully strip all windows.
My position is going to be: I believe the work done falls within your quote. We've already paid you extra as a sign of good faith. If you want more money I invite you to take me to disputes tribunal, and if you keep asking for money I will take you to the disputes tribunal.