The scope, written down once
Agree what is being built, to what specification, including the items that are still undecided and how they will be chosen. A short written scope is worth more than a long conversation nobody can recall in March.
Drawings and a specification attached to the agreement do most of this work for you.
How payment works
Pay for work that exists. Stage payments tied to milestones that can be seen and measured protect both sides, because the builder knows what triggers the money and you know what you are paying for.
Avoid payments that run ahead of the work. If a job stops, whatever you have paid above the value in place is money you are chasing rather than holding.
How changes get priced
Changes are normal on a house. What matters is that each one is priced before it is carried out, in writing, including any effect on the finish date.
Agreeing the mechanism at the start costs nothing. Agreeing it after the fifteenth change is a negotiation you will lose.
Dates, retention and defects
Set a start and a finish date, and say what happens if the finish date passes. Agree a small retention held until the defects are put right, and a period in which to raise them.
None of this is hostile. It is the part of the arrangement that lets both sides carry on working while something is being sorted out.
What this means for you
The paperwork that protects a homeowner is short. It is the absence of it that makes projects expensive, because every question becomes a matter of whose memory is better.
Reltic reviews home building agreements before they are signed and explains, clause by clause, what each one will mean on site.
Have the agreement read before you sign
Send the quote and whatever the builder has proposed. We will tell you what it says and what it leaves open.