How to Choose and Check a Building Contractor

Every route to a builder has something going for it, and none of them removes the need to check. A recommendation from someone you know is often the best start, because you can see the finished work and ask how the job went. It is still worth running the same checks, because a builder who suited a small repair may not be set up for a larger job. Should I use a builder a friend recommended? looks at this in more detail.

Trade scheme registers and directories give you names alongside some level of vetting, but what each one checks varies a great deal. Read what the listing actually means before you rely on it. Contractor networks and coordinators appoint a contractor for you and, depending on the arrangement, run the process around the job. Going direct gives you full control and full responsibility for every check. Directories vs networks vs going direct compares all three.

Whichever route you take, a builder who approaches you unprompted, at the door or by phone, deserves the most care. Trading Standards and Citizens Advice both advise against agreeing to work from a cold call, and against being rushed into a decision on the day. A reputable business will leave you a written quote and give you time.

How many names you need depends on the job. For a small repair, two quotes may be enough. For a larger project, three gives you a sense of the range without turning the process into a second job. Comparing more than that rarely tells you much more.

Public liability insurance covers a business if its work injures someone or damages somebody else's property, which on a domestic job can include your home and your neighbour's. It is not a legal requirement for builders, but it is the cover homeowners most often ask to see, and a builder without it is leaving any claim to be settled from their own pocket.

Employers' liability insurance is a different thing. It covers the business's own employees, and a business that employs people is generally required by law to hold it, with some exemptions. The Health and Safety Executive publishes the rules. On larger jobs you may also come across contract works cover, which protects the work in progress and materials on site, and professional indemnity cover, which matters where a firm is giving design advice.

The check that matters is simple. Ask for the certificate or schedule, make sure the name matches the business on your quote, check the dates run past your job, and make sure the activities covered include the work you want done. What insurance should a builder have? gives the quick answer.

Insurance and warranties are often confused. Insurance deals with accidents and damage. A workmanship warranty is the builder's promise to put their own work right if it proves defective. You want both, and they are set out in different documents.

Online reviews are useful when you read them as a pattern rather than a score. Look at several platforms, sort by newest, and read the middling and negative reviews alongside the glowing ones. How a business replies to a complaint often tells you more than the complaint itself. Very large numbers of short, similar reviews posted close together are worth treating with caution. Are online reviews of builders reliable? covers the limits.

References fill the gaps reviews leave. Ask for recent customers with jobs like yours and ring them. Useful questions are simple: did the builder turn up when they said, did the price change, how were problems handled, and would you use them again? You are entitled to ask, and a good builder expects it. See can I ask a builder for references?

Previous work is the most direct evidence of all. A job finished a year or two ago shows how the work has lasted, not just how it looked on the day. Where you can, look at something similar in scale and type to your own project. Checking previous work explains what to look for without needing trade knowledge.

A quote is where the checks turn into a decision, so it pays to get quotes that can be compared fairly. Give each builder the same description of the job, ask for a written quotation rather than a verbal figure, and check that each one covers the same work, the same materials and the same extras, such as scaffolding and waste removal.

Expect quotes to differ. Builders price risk, access and materials differently, and some include things others leave out. A quote far below the rest is worth a closer look rather than an instant yes: ask what is included and what might be added later. Is a very cheap quote a bad sign? covers this.

If a builder won't put a price in writing, that is worth pausing on. A written quote protects both sides, because it records what was agreed before anyone's memory of a conversation starts to differ. For comparing quotes line by line, deposits and payment schedules, our guide to building quotes and payments goes into detail.

Checking builders is not difficult, but it adds up. Shortlisting, looking up companies, reading insurance documents, ringing references, attending visits, chasing quotes that are late and comparing the ones that arrive can easily fill several evenings on a modest job, and more on a large one.

That is time well spent, and plenty of homeowners are happy to spend it. It is also why some people choose a route where part of the checking and chasing is done for them. The time cost of doing it yourself sets out where the hours go, and do I need a project manager for a small job? helps you decide how much help makes sense.

Whichever you choose, the checks themselves do not change. A coordinator, a directory or a friend can narrow the field, but the questions in this guide are still the right ones to have answered before you commit.