Start with a Proper Written Quote, Not a Verbal Ballpark

A friendly conversation on the driveway is a lovely way to begin a project, but it is a terrible basis for one. Ask every builder you shortlist for a written quote that breaks the work down room by room, or stage by stage, rather than one lump sum. You want to see labour and materials listed separately, along with anything that is excluded.

Exclusions matter more than most homeowners expect. A quote that does not mention skip hire, scaffolding, plastering, waste removal or making good after electrical work is not necessarily a cheap quote — it is an incomplete one. Ask directly: “If I accept this, what else might I realistically have to pay for?”

Check too whether the price includes VAT, and confirm the builder’s registration number if they are VAT registered. For anything involving gas, electrical work, roofing at height or structural alterations, ask for the relevant certification and, where applicable, building control approval. A good builder will have these to hand and will not be offended by being asked.

Set Up Staged Payments Tied to Milestones

The single most common cause of renovation disputes is money moving faster than the work. Never pay a large sum up front “to get the materials in”. A reasonable deposit is usually enough to cover initial ordering, and even then it should be modest.

Instead, agree a schedule of staged payments linked to completed milestones. A typical structure for a mid-sized renovation might look like this:

• Deposit: a small percentage on signing, to secure the start date and cover initial orders
• Stage one: on completion of strip-out, groundworks or foundations
• Stage two: on first fix — electrics, plumbing, insulation, plasterboard
• Stage three: on second fix and decoration
• Final payment: a retention of 5–10% held for two to four weeks after completion, released once snags are signed off

Write the milestones down in plain language. “On completion of first fix” is clear. “When the job is 60% done” is an argument waiting to happen. Pay by bank transfer so there is a clear record, and ask for an invoice against each stage.

Decide Who Orders and Pays for Materials

This is the point where goodwill quietly disappears if it is left vague. Builders often have trade accounts and can source timber, plaster, tiles and sanitaryware more cheaply than you can, and they carry the risk if something arrives damaged or the wrong size. That convenience is worth having.

If the builder is ordering, make sure the quote states this clearly, and ask to see receipts for any items you are paying for at cost plus a percentage. If you are ordering — which many homeowners do for kitchens, bathrooms and tiles — accept that you also own the delays. A late delivery is not the builder’s fault, and a builder standing idle on site still needs paying.

Agree in advance:

• Who holds the trade account and pays the supplier
• Where materials will be stored, and who insures them
• What happens if you supply something faulty or the wrong size
• Who covers the cost of returning surplus or incorrect items

If you are supplying goods, tell your builder the delivery dates in writing and keep a copy. Most will happily work around them if they know in advance.

Agree a Realistic Schedule and Build in Slack

Ask for a written programme showing the order of works and rough durations. Renovations rarely run to the day, and a builder who promises an immovable finish date with no allowance for weather, deliveries or building control inspections is either optimistic or inexperienced.

Expect the schedule to shift, and agree how you will both handle it. A weekly catch-up — ten minutes on a Friday, or a short message thread — keeps small problems small. If something is going to slip, you want to hear it early, not on the morning the kitchen fitters arrive.

Price Changes Before the Work Starts

Changes are normal. Walls turn out to be solid where you expected studwork, or you decide halfway through that you want the boiler moved. What causes trouble is doing the work first and discussing the cost afterwards.

Agree a clear process at the outset. Any change should be written down, priced and approved by both of you before it goes ahead. For genuinely unforeseen work — the classic hidden lintel or a rotten floor joist — agree a day rate and materials markup in advance, so there is a fair default when a proper quote is not practical.

Keep a contingency of 10–15% of the project value for exactly this reason. It is not wasted money; it is the difference between a calm renovation and a stressful one.

Keep Records and End the Job Properly

Keep everything in one folder, digital or paper: the quote, the payment schedule, variation notes, receipts and any messages where you agreed something. A short email confirming “we agreed the extra radiator in the hall for £X, to be paid at final stage” takes thirty seconds and saves hours later.

At the end, walk the site together and draw up a snagging list — every sticking door, missed paint edge and loose tile. Give the builder a reasonable window to put things right, then release the retention once you are satisfied. A warm handshake and a prompt final payment is the best possible ending. You may well want them back for the next project.