Before Your Builder Arrives

Why a bit of prep saves a lot of money

Builders are different from other trades — they are going to be in your house for days or weeks, not hours, and the single biggest cost of a poorly prepared site is not money, it is time. A builder standing around while you finish clearing the utility room is still being paid.

This guide is about the prep you do in the week before the start date — not products. If you are looking for the tool side, we have a separate piece on what to buy before your builder arrives; this is the project-management checklist the builder wishes every client did.

The 24-hour checklist

Run through these the day before the builder is due. None of them require any skill beyond what a normal householder already has — but they collectively shave real money off the final invoice.

• Confirm start date and hours in writing. A text or email saying 'Monday 8am, finishing 5pm, no weekends' saves the awkward conversation on day 3 when they want to come in at 7am. Agree whether they work bank holidays. Forward it to any neighbour who shares a party wall.
• Do the neighbour round. Hand-deliver a short note to each neighbour two weeks before: your name, builder's name, the dates, who to ring if their car gets blocked in, and a polite apology in advance. Nine neighbour disputes out of ten start because someone wasn't told.
• Secure a dust barrier plan with the builder. Before they start, agree in writing where they are going to put temporary polythene screens — staircase landings, the door to the living room, the top of the kitchen. This stops fine dust ending up in every drawer in the house.
• Empty the rooms entirely — including what is in the loft above. If they are knocking through downstairs, everything in the loft above will move when joists flex. Take cardboard boxes out of the loft. Take pictures off walls that share a wall with the work area.
• Protect floors through the walking route. Builders walk in and out all day with boots. Self-adhesive carpet-protect film on carpet, hardboard taped down on wooden floors, thick cardboard on tile. Do this the day before.
• Arrange skip and parking. Check your local council's skip-permit rules — in most of Kent you need a permit (£30-£60) to put a skip on a public road. Confirm the builder has this booked, or whether it is on your invoice. Suspended-bay parking takes 5 working days in most boroughs.
• Agree how deliveries and waste removal work. Sand, cement, plasterboard, steels — whose drive, when. Waste — is it in the price, or does it get added after? Get it in writing before day 1.
• Sort out water, electric and a loo. Builders need a tap and a socket, and they need a toilet. Decide in advance whether they are using your downstairs loo (put a lock on the other rooms) or bringing a portaloo (agree where it goes).
• Check your buildings insurance. Some policies require you to notify them of work over £10k. A ten-minute phone call now saves a declined claim if something goes wrong.

Tools worth having ready

These are the things the builder will either ask for, borrow, or charge you labour to go fetch. Keeping a small dedicated set in a cupboard means you never lose the 20 minutes that turn into the next half-hour block on the invoice. All prices move, so we link to live Amazon UK searches rather than fixed ASINs.

Questions to ask when they arrive

Asked politely on the doorstep, these five or six questions filter out 90% of the problems that turn into complaints later. A professional will welcome them; a cowboy will get irritated.

• Who is the lead person on site each day? On medium-sized jobs the builder you booked may not be swinging the hammer every day. Ask who you speak to for decisions — it should not change mid-job.
• What is the timeline for the key milestones? Ask for a one-page schedule with demolition, first-fix, second-fix, plastering, decoration and final clean dates. Missing dates aren't disastrous but missing all of them by a week each is.
• What does 'making good' mean in our contract? 'Making good' is builder-speak for patching. Clarify: do they plaster over the hole, or just skim it? Do they paint the patch, or just the hole? Do they repaint the whole wall? These three interpretations differ by £400+.
• How do we handle variations from the quote? Agree in writing that any extra work above (say) £100 gets a variation order signed by both parties before it starts. Otherwise you get a £3000 'surprise' on the final invoice.
• What is the payment schedule? Never pay 100% upfront. 10-20% deposit, staged payments on milestones, and hold 5-10% retention for 30 days after handover. FMB contracts have templates.
• Who handles the Building Control sign-off? Most domestic extensions need building control inspections at foundations, DPC, pre-plaster and completion. Confirm whether the builder books them or you.

Red flags during the visit

If you see any of these on the day, slow things down. You are not obliged to let anyone continue work you are uncomfortable with — even if they've already been there an hour.

• They ask for a large cash deposit before any materials are bought. A £500-£1000 deposit covers early materials on a £20k job. A £10,000 'deposit' before anything has arrived on site is a scam pattern.
• There is no written contract. FMB, TrustMark and Federation of Master Builders all publish free template contracts. A builder who won't use one is either avoiding tax or avoiding being held to anything.
• They change the spec on the fly without telling you. Switching a specified PIR insulation for a cheaper rockwool, or a Velux for an unbranded roof window, without a conversation, is a sign the rest of the job will go the same way.
• No Construction Industry Scheme (CIS) paperwork for subcontractors. If their electrician and plumber are subcontracted, they should be registered under CIS. Missing paperwork suggests cash-in-hand labour with no comeback if it goes wrong.

What to do after the visit

The paperwork and follow-up is where homeowners most often lose money — warranties unregistered, certificates not received, insurance claims unfiled. Run through this list before you pay the final invoice.

• Hold the final 5-10% retention for 30 days post-completion to fix snags.
• Walk the site with the builder and produce a signed snag list — small defects they agree to come back and sort. Photograph each snag.
• Get the Building Control completion certificate before the final payment.
• Get copies of any electrical (EIC), gas (CP12) and plumbing certificates for sub-contracted work.
• Keep all receipts for building materials — some are eligible for VAT reclaim on new-builds and listed-building repairs.
• Register any appliance warranties (boilers, cookers, ovens) in your own name.

Find a builder in Kent

• Builders in Kent — county-level directory
• Builders in Maidstone
• Builders in Canterbury
• Builders in Dartford
• Builders in Tunbridge Wells
• Builders in Ashford

Related guides

• How to Choose a Builder — the sister guide to this one, covering qualifications, quoting and insurance.
• Trade Shop — curated tools and homeowner kit, by category.
• All Guides — every NearbyTraders homeowner guide, in one place.