What to ask a home improvement contractor

Get three quotes, check insurance and warranties, and make sure the contract spells out exactly what’s being done, with what materials, by when, for what price.

Home improvement is a massive bucket – it covers anyone from a kitchen fitter to a window installer to a full renovation contractor. The common thread is that the jobs are expensive, take weeks or months, and go wrong in memorable ways when they go wrong. There are home improvement contractors listed on WotsItCalled, and the due diligence matters more here than almost anywhere.

Match the contractor to the job

• Kitchen fitter. Specialises in kitchens. Usually works with a kitchen supplier (Howdens, Wren, Magnet, independent) who designs and sells the units. The fitter installs them. Some handle the plumbing and electrics too, some don’t.
• Bathroom fitter. Similar story. Often tiles, plumbing, and electrics in one trade – or a lead tradesman who brings in specialists.
• Window installer. Should be FENSA or CERTASS registered. Either of those means they can self-certify Building Regulations compliance. Without that, you’re the one responsible for notifying Building Control.
• Extension builder. Back to general builder territory – see the B13 guide. Plus an architect or structural engineer for the design.
• Loft conversion specialist. Often a specific firm that handles everything – design, structural calcs, build, fit-out.
• Driveway and landscaping. Drives are their own specialism. Look for Marshalls-approved or Brett-approved installers.

Registrations that actually mean something

• FENSA / CERTASS. Window and door installers. Covers self-certification under Building Regs.
• Gas Safe. Any gas work. Non-negotiable.
• NICEIC / NAPIT. Electrical work. Self-certifies Part P.
• TrustMark. Government-endorsed across trades. Members follow a code of practice.
• Which? Trusted Trader. Vetted and monitored. Not free for the trader – so a signal of commitment.
• HETAS. Solid fuel appliances, wood burners.
• MCS. Renewable energy installs – heat pumps, solar. Required for grant schemes.

One of these schemes ticked is a starting point, not a guarantee. But it narrows the field massively.

The quote stage – what you should actually get

A proper home improvement quote is three pages, not three lines. It should cover:

1. Itemised labour and materials. Every component costed. Kitchen units, worktop, appliances, taps, plumbing, tiling, electrics, removal of old kitchen, waste disposal – separate lines.
2. Brand and specification. Which tap. Which worktop. Not “a tap”. You should be able to cross-reference every item if you want to.
3. Timeline. Start date, expected duration, any known gaps (waiting on parts, trades).
4. Payment schedule. Staged, not up front. More on this below.
5. VAT. Included or excluded, clearly marked. £10,000 + VAT and £10,000 including VAT are different bills.
6. Exclusions. What’s NOT in the quote. Unexpected structural work, decorating, making good. Worth knowing before you sign.

Payment terms that won’t burn you

• Small deposit, if any. 5-10% tops to secure the booking. More than that for materials is fair, but only if you’re seeing the invoice.
• Stage payments on completion of each phase. Not at the start. Not at the midpoint. At the completion. “First fix complete”, “second fix complete”, “install complete”.
• Final 5-10% on snagging. You hold it back until everything on your snagging list is sorted. This is what gets the last mile done.
• Bank transfer, not cash. Trail for both sides.

Questions to ask before signing

1. How long is the warranty on the work, and who underwrites it? The contractor themselves, or a scheme like FENSA or TrustMark? Scheme-backed warranties are more valuable – if the contractor goes under, you still have cover.
2. Who handles building control / planning notifications? Get this in writing so it doesn’t fall between you.
3. Can I see a recent job of the same type? Not a photo. A real one you can drive to and ideally speak to the owner.
4. What’s your snagging process? Decent contractors expect snagging and have a process. The bad ones treat every snag like a personal insult.
5. What happens if you hit a problem we didn’t expect? A variation process. Any extras should be quoted separately before they’re done.
6. What are your hours on-site, and how do you handle mess and waste? Protection of existing floors, skip placement, end-of-day clean-up. All worth agreeing before you’re living in it.

Where to find them

The home improvement directory covers contractors across the UK. Liverpool, Manchester, Leeds, Birmingham. Shortlist three, get three quotes, ring every reference, check every registration.

When things go wrong: how to handle it

Even with the best due diligence, things sometimes go wrong. How you handle the first problem usually decides how the rest of the job goes:

• Raise it in writing, calmly, specifically. Not a rant – a clear description of the problem, photos if useful, what you want done.
• Give them a chance to fix it. Most decent contractors welcome the chance. It’s the bad ones who get defensive.
• Keep paying on schedule if the work is still progressing. Withholding payment on a job that’s mostly fine escalates things fast.
• Document everything. Dates, conversations, photos. If it goes to dispute, you’ll need it.
• Use the scheme if there is one. TrustMark, FMB, and Which? Trusted Trader all have dispute resolution processes. Cheaper and faster than court.

The short version

• Match the contractor to the job – kitchen fitters, bathroom fitters, window installers are different specialisms.
• Look for scheme registrations (FENSA, TrustMark, NICEIC, Gas Safe) that mean something legally.
• A proper quote is itemised, brand-specific, timed, and spells out VAT and exclusions.
• Stage payments on completion, never up front. Hold 5-10% back for snagging.
• Scheme-backed warranties protect you even if the contractor disappears.

WotsItCalled is a free UK business directory. No signup, no catch. Find the place everyone’s on about, or browse the full home improvement contractors directory.