How to Avoid a Bad Builder: The Checks That Take One Afternoon

Almost every bad build is decided before anyone lifts a tool. The failures that cost people their savings are not craftsmanship failures — they are choices made at appointment, and 4 checks that take a single afternoon filter out most of them: the company, the cover, a job in progress, and the direction the money flows.

I have watched this go wrong the same way for years, and it almost never starts with bad bricklaying. It starts with a price that was never written down properly, a payment that got ahead of the work, and a scope nobody agreed. By the time the workmanship is visibly wrong, the homeowner has usually already lost the leverage they needed to fix it. The estimator gives you a stage-by-stage range to hold every quote against, and how we run renovations sets out the contract side of what follows.

The four checks, in the order that matters

Do these before you take anyone seriously. None of them requires a qualification, and together they take an afternoon.

1. 011 · Search the company at Companies House. Free, public, and it takes two minutes. You are looking for how long the company has existed, whether accounts have been filed on time, and whether the same director has a run of dissolved companies behind them. A brand-new company is not disqualifying — everyone starts somewhere — but a new company run by someone whose last three closed owing money is a pattern, and it is visible before you pay anyone.
2. 022 · Ask for the insurance certificate, then check it yourself. Public liability cover is the one that matters to you, because it responds if your house or your neighbour's is damaged. Ask for the certificate, then confirm the insurer, the policy dates and the level of cover independently. A screenshot on a phone proves nothing, and a policy that lapsed in March is worth exactly as much as no policy. If the work involves employees rather than a sole trader, employers' liability is a legal requirement as well.
3. 033 · Visit a job in progress, not a finished one. A finished room tells you about the decorator. A live site tells you about the builder. Look at how materials are stacked, whether the site is dry and safe, whether there is a working welfare setup, and whether anyone can tell you what is happening that week without checking. Ask the homeowner on that job one question: what happened when something went wrong? Every project has a bad week. The answer tells you what yours would look like.
4. 044 · Find out which direction the money flows. Ask exactly what is payable, and when, before any figure is discussed. You want payments that follow work already done and that you can stand in front of. A structure that asks for large sums in advance of delivery has moved the risk onto you, and it is the single most reliable predictor of the situations that end badly. This is a scheduling question, not a haggling one, and it is fair to ask it early.

What a bad builder actually looks like

Not what most people expect. The stereotype is someone who turns up late, leaves a mess and cuts corners on the plastering. Those are real and they are irritating, and they are also recoverable — you can withhold money, you can get it redone, you can part company.

The builds that genuinely hurt people follow a different shape, and it is almost always financial. The work starts well. The relationship is good. Then a payment is requested slightly ahead of the work — for materials, for a supplier, for a deposit on windows. It seems reasonable, because it is a reasonable-sounding thing to ask. Then another. By the time progress has visibly stalled, the client has paid for more than has been built, and every option they have left is expensive.

That is why the payment structure sits in the four checks above and the workmanship does not. Craftsmanship problems are fixable while you still hold money. Nothing is fixable after you have paid for work that does not exist.

Key takeaway

A builder who is behind on your money has a reason to come back on Monday. A builder who is ahead of it has a reason to be somewhere else.

The obligations that exist whether or not anyone mentions them

Part of avoiding a bad builder is knowing which duties are already law, because a contractor who is vague about these is telling you something. None of this is optional, and none of it depends on the size of the job.

Approved Documents are statutory guidance to the Building Regulations 2010 for England. Compliance is judged against the Requirements in Schedule 1; the Approved Document shows one way of meeting them. Your building control body has the final word on your specific building.

Approved Documents are statutory guidance to the Building Regulations 2010 for England. Compliance is judged against the Requirements in Schedule 1, and your building control body has the final word on your specific building.

You do not need to quote any of this at a builder. You need to be able to tell the difference between someone who says “yes, that’s a party wall notice, it needs to go out two months before we dig” and someone who says “don’t worry about that”. The second answer is the finding.

Choosing the right kind of contractor, not just a good one

A great deal of unhappiness comes from hiring a perfectly competent firm of the wrong shape for the job. These are honest trade-offs rather than good and bad options, and the right answer depends on what you are building.

If you are weighing where the work should go at all, our loft conversion page and the extension guide cover the two decisions that most often sit underneath this one.

The paperwork that settles everything else

Once someone has passed the four checks, almost all remaining risk is contractual. You do not need a lengthy standard form. You need six things written down, and a contractor who resists writing them down has answered your question.

The scope, in enough detail to be argued about. Not “rear extension”. What is included, what is excluded, and what has been assumed about the things nobody can know yet — foundation depth, the state of the drains, whether there is asbestos. A quote that states its assumptions is not hedging. It is showing you where the risk sits.

The price basis. Whether it is a lump sum against that scope, a schedule of rates, or a cost-plus arrangement. All three are legitimate. Confusion between them is not, and it is the origin of a large share of the disputes I see.

The dates. A start date and a completion date, in the contract, with a stated consequence if they slip. A contractor who will not put a completion date in writing is telling you they do not control their own programme.

The payment points. What triggers each payment, and what it is worth. Tie them to work you can see rather than to weeks on a calendar.

How a variation gets priced. Every job changes. The question is whether the change gets priced and approved before the money is spent or explained afterwards. This one clause prevents more arguments than the rest combined.

Who holds health and safety. Name the principal contractor. It is already their duty under CDM 2015; writing it down means everyone knows.

Warning signs, in order of seriousness

Ranked by what they actually cost you, rather than by how annoying they are.

1. A large payment wanted before anything is delivered. The single most serious signal, and the one most often rationalised away.
2. A refusal to put the scope in writing. Everything you would later want to enforce lives in this document.
3. A single-line price. One number for a whole build cannot be checked, compared, or valued mid-job.
4. Pressure to decide this week. A genuine programme constraint gets explained; urgency without a reason is a technique.
5. No completion date. See above.
6. Vagueness about building control or party wall notices. Either they do not know, or they were not planning to.
7. Cash-only, or a discount for paying outside the company. It removes your consumer protection along with the receipt.
8. No willingness to show a live site. Every working builder has one.

Notice what is missing: not being the cheapest, not having a glossy website, not being available immediately. None of those predicts anything.

What we do about it, specifically

I would rather show you our own answer than describe a standard.

We are the builder rather than a marketplace — one contract, one named project lead, and no introducer fee stacked on the build cost. On payment, the direction is the whole point: you pay 10% to mobilise and then weekly, against work already done, with 5% of the price held back until the end of the 12-month defects period. Your money does not get ahead of the build, which means the leverage stays where it belongs.

Every variation is priced and dated before a penny is spent on it. Every contract carries a 12-month workmanship warranty on second-fix fittings, backed by 2VP and signed by the trades who did the work; a 10-year HomePro insurance-backed guarantee is optional, arranged on request and paid by you directly to HomePro at 2.5% of the contract value. And the completion date is in the contract, with a stated consequence if we miss it.

You should ask any contractor you are considering for their version of that paragraph. The answer, or the absence of one, is the most useful thing you will learn all week.

The takeaway

Do not try to assess craftsmanship you are not qualified to assess. Assess the things anyone can check: the company record, the insurance certificate, a live site, and which direction the money flows. Then get the scope, the dates, the payment points and the variation process in writing. The builds that go wrong were nearly all decided at that table, before a single brick moved.