Hiring a builder safely in Northern Ireland: payment schedules, contracts and red flags

Step 1 - Get the scope of work in writing before you compare prices

A quote is only meaningful if every builder is quoting the same job. Before you ask anyone for a price, write down - in plain English - what you actually want done. Include the rooms involved, the materials you have a preference for, the dates you want it started and finished, and any rubbish-removal expectations.

Send the same written brief to every builder you ask. When the quotes come back, you can compare like-for-like. If a quote is suspiciously low, the cause is almost always that the builder has assumed cheaper materials, fewer days on site, or that something you assumed was included isn’t.

Step 2 - Vet the builder properly

A registered company name on a quote is not a credential. Before you accept any builder’s price, do these five things:

• Ask for a current public liability insurance certificate, dated to the present, with at least £1,000,000 cover. Read the cover dates - many lapse annually.
• If the work involves gas, verify the Gas Safe registration number on the Gas Safe Register on the day of hire - not last month.
• If electrical work is involved, verify NICEIC, NAPIT or ECA membership directly on each body’s public register on the day of hire.
• Check Companies House for the registered company address, directors and filing history. A dormant company or accounts overdue is a flag.
• Ask for two recent customer references - and actually phone them. Ask whether the work matched the quote, whether the timescale slipped, and whether the final invoice matched expectations.

You can verify these directly on the official public registers: Gas Safe Register, NICEIC and Companies House. All three are free to search.

Public liability insurance, by the way, isn’t optional padding - it’s the policy that pays out if your builder accidentally puts a foot through your ceiling, damages a neighbour’s wall, or causes a fire. Without it, your only route to recover damage costs is to sue them personally, which is slow and often fruitless.

The builders most likely to let you down rarely advertise. They knock the door or cold-call. If that is how you were approached, read our guide to rogue traders and doorstep scams in NI before you agree to anything.

Step 3 - Get a written contract, even for small jobs

A contract doesn’t have to be a 30-page legal document. For a typical refurb or extension job, a one-page agreement signed by both parties will suffice and will save you serious pain if the relationship breaks down. It should set out:

• The full scope of work, with materials and finish specified where you care about them.
• The total fixed price, broken down by stage if there are stages.
• A payment schedule (more on this below).
• A start date and a target finish date, plus what happens if the finish date slips materially.
• Who is responsible for skip hire, scaffolding, building control sign-off and any required certifications.
• How variations to the scope (the dreaded “while we’re at it” moments) will be priced and approved in writing before the work happens.
• What standard the work will be completed to (a sensible default in the UK is the relevant British Standard plus manufacturer’s guidelines for any product installed).
• A short defects-liability period - usually 12 months - during which the builder will return at no cost to fix anything that fails.

You can write this yourself, sign two copies, and that’s a perfectly enforceable agreement. The key is that both parties know what they’ve committed to. A builder who refuses to put it in writing is telling you something.

Step 4 - Structure stage payments - never pay the full cost upfront

The single biggest preventable cause of homeowners losing money to a builder is paying too much, too soon. The structure that protects both parties is:

• A small deposit only if materials need ordering before the job starts (typically 10-15% of the total). For a job under £2,000 you should not need to pay any deposit at all.
• Stage payments aligned to milestones - e.g. on completion of foundations, on completion of first-fix, on completion of plastering. The builder gets paid as they progress, you get to inspect as you pay.
• A retention of around 5-10% held back until 14-28 days after practical completion. This gives you time to spot snags and gives the builder a strong incentive to come back and fix them.

For very small jobs (a day or two of work), payment in full on completion is fine and normal. For anything larger, the deposit-and-stage-payments structure is the industry default. Any builder pushing for the full amount up front, or for a much larger deposit than makes sense for the materials they need to buy, should be politely refused.

Payment-schedule template by job size

The right shape of a stage-payment schedule depends on how big the job is. Small refurbs use few stages with bigger percentages; large extensions use more stages with smaller percentages so neither side is over-exposed at any point. The table below covers the four job-size brackets you actually hire builders for in NI.

Source: FMB recommended stage-payment guidance for member contractors, plus Trading Standards NI homeowner consumer-protection bulletins. Adjust upward if the builder needs to order high-value bespoke materials before mobilising.

NI trade-body comparison: FMB, CIOB, Federation

Three umbrella bodies cover most credentialled NI builders. None are statutory, but each carries different vetting and dispute-resolution implications. The table summarises what each costs the builder, what the homeowner gets in practice, and whether NI Building Control treats membership as meaningful.

Source: FMB, CIOB and Federation of Master Builders 2026 published member-benefit schedules and complaint-resolution policies, plus Trading Standards NI member-recognition guidance. Membership of any of these is a positive signal but not a substitute for verifying current insurance and any required trade-register status on the day of hire.

Step 5 - Pay by traceable method and keep records

Pay by bank transfer or card wherever you can. Cash payments leave no audit trail, give no consumer-protection rights, and - if the builder is later found not to be paying tax - can in theory expose the householder to questions too. If a builder offers a discount “for cash”, it’s rarely worth it once you factor in the lost protections.

Keep every quote, every invoice, every text or email exchange about variations, and every receipt for materials you bought yourself. If a dispute does arise, the side with the documentation almost always wins.

Red flags - the patterns that almost always end badly

After thousands of jobs, the warning signs are remarkably consistent. If you spot any of the following, walk away - there are plenty of good builders.

• Refuses to provide a written quote with a breakdown.
• Asks for a deposit that’s a large percentage of the job before any materials are ordered.
• Pressures you to decide today, with a "discount" if you sign now.
• Won’t share an insurance certificate, or shares one whose dates have lapsed.
• No fixed business address - only a mobile number and a Facebook page.
• Vague about credentials - claims to be "registered" but won’t name the body or give a number.
• Drives a vehicle with no signage and asks to be paid in cash only.
• References they give are reluctant to talk or sound rehearsed.
• Wants to start "tomorrow" without inspecting the job properly.
• Mid-job, asks for a large additional payment before continuing - without any agreed variation.

If something goes wrong

Even with all the above, occasionally things go wrong. The order of escalation:

• Raise the issue in writing - email, with photographs if relevant. Give the builder a fair opportunity to put it right.
• If they refuse or stall, write a formal letter quoting your written contract and the Consumer Rights Act 2015 (which guarantees that services be provided with reasonable care and skill).
• If you paid by credit card and the bill exceeded £100, you may be able to claim under Section 75 of the Consumer Credit Act 1974 - speak to your card provider.
• For small claims under £3,000 the Northern Ireland small-claims court is straightforward, low-cost and you do not need a solicitor. See the official guidance at nidirect.gov.uk for current procedure.
• For larger or more complex disputes, mediation through an independent provider is usually faster and cheaper than litigation.

NI-specific procedural guidance for the small-claims court is on nidirect: make a small claim, and broader homeowner consumer rights are covered by The Consumer Council for Northern Ireland.

How NI Trades fits in

We run application-stage checks on every tradesperson who lists with us - identity, public liability insurance, claimed credentials, and two referees. When you hire someone through the platform, you get their full contact details and the protection of our review system. But these checks are made at application stage, on a specific date - they don’t replace your own due diligence on the day of hire. Always re-verify insurance and credentials before any work or money changes hands. The advice above applies whether you find a tradesperson through us, through word of mouth, or through any other route.