Dispute with a Building Contractor: The Most Common Mistakes Clients Make

You're sitting with a lawyer and it turns out you have no contract, your evidence is scattered somewhere on an old phone, and to top it off, your last email to the builder said "ok, all done, thanks". The judge looks at you sympathetically and says: "I'm afraid this is going to be difficult."

Most disputes with building contractors are lost not because the law doesn't protect the client, but because clients make their own case harder to prove. This guide runs through the most common mistakes — and how to avoid them now, before anything goes wrong.

This guide is general legal information, not legal advice. How the rules apply depends on your individual circumstances — the contract, the evidence, and whether the matter is consumer, civil, or business-to-business. If you need advice or representation, the matter should be assessed by a qualified Polish lawyer.

MISTAKE #1: No written contract (or a messy one)

What happened: You met someone through a friend who does renovations. You agreed verbally: "Kitchen renovation, PLN 50,000, finished by end of May." You shook hands, and he got to work.

Why this is a mistake: A verbal contract is valid in theory — Polish civil law (kodeks cywilny) allows it — but in court it's practically useless. How do you prove the terms when everyone remembers something different?

The judge hears: - You: "It was supposed to be finished by end of May, PLN 50,000, materials included." - The contractor: "The agreement was PLN 60,000, materials excluded, and end of July." - Witnesses on each side: "heard something different."

Result: the court has no way of knowing what was actually agreed. And you can lose.

What to do to protect yourself:

• ☐ Always get it in writing — text message, email, or, ideally, a paper document.
• ☐ It should cover:
• Scope of work (specifically what's being renovated).
• Price (total figure; is VAT included?).
• Timeline (start date, finish date, and any interim milestones).
• What's included in the price and what counts as "extra" (e.g. materials, fittings, replacements).
• Payment terms (deposit? how much? when's the balance due?).
• What happens if there's a delay.

• Sign-off arrangements (will there be a handover report?).

• ☐ Both sides sign off — even a text saying "I confirm these terms" is enough.

Example of a simple text-message agreement:

"Confirming — kitchen renovation (unit replacement, painting, wiring, excluding light fittings), price PLN 50,000 (VAT included), starting 1 May, finishing 31 May 2026, deposit PLN 25,000 up front, balance on handover. Materials on your side. Text or email me back if you agree."

The contractor replies: "Agreed" — and you have a contract.

MISTAKE #2: No deposit paper trail (or a deposit with no receipt)

What happened: You said "take a PLN 20,000 deposit", and you handed over cash with no receipt. No transfer, no acknowledgement. A week later, he's gone.

Why this is a mistake: Without proof of payment, the court won't simply take your word for it. You say "I paid in cash", he says "no, you didn't", and that's where it ends. No paperwork, no leg to stand on.

What to do:

• ☐ Always pay by bank transfer where possible. A bank record is hard to dispute.
• ☐ If it's cash — get a receipt marked "Deposit for renovation work" signed by the contractor to confirm he received it.
• ☐ Split the deposit into instalments — don't hand it all over at once. Something like 40% + 30% + 30%.
• ☐ After every payment — send a confirmation text: "Confirming deposit payment of PLN 20,000 on [date]. Work is due to start 1 June."

MISTAKE #3: No record of the starting condition

What happened: The contractor started work, and you never photographed what the room looked like beforehand. Now he says: "That wall was already damaged, that wasn't me." You say: "No, it was straight!" He says: "Prove it."

Why this is a mistake: In renovation disputes, the evidence is mostly photos and video. Without them, why would anyone believe you over him?

What to do:

• ☐ Take photos BEFORE work starts — the room from every angle, walls, floor, corners, everything that's going to be touched.
• ☐ Record the date — either it's visible in the photo's EXIF data (you can check this later), or you text yourself/the other party clearly today: "Taking before photos, dated [date]."
• ☐ Photograph the work as it happens — especially anything "destructive" (removing doors, breaking up tiles).
• ☐ Keep everything in one folder — all photos and video, dated, in a single place.

Tip: Smartphones automatically save the date in the photo's EXIF metadata. If a dispute arises, you can pull up the file properties and show exactly when a photo was taken.

MISTAKE #4: Signing off work with no handover report

What happened: The contractor says: "All done, have a look." You walk round the room, notice something's off (a badly finished corner, or the wrong shade of paint), but you say "ok, thanks" because you wanted to get him out the door.

A week later it starts flaking off. You call — he says: "You looked at it, you signed it off, I'm not fixing it."

Why this is a mistake: If you sign "accepted with no reservations" or simply say "ok", the court is much less inclined to believe you later when you claim there was a defect. You could have raised it at the time.

What to do:

• ☐ Never sign off "no reservations" — always sign off "with reservations", or simply don't sign if something isn't right.
• ☐ Before you sign anything — walk through every room, check the corners, run your hand over surfaces, look at the finish in natural light.
• ☐ If something's wrong — flag it immediately: "This wall is uneven here, this bit is patchy there, that's not what we agreed."
• ☐ Photograph any defects — before anything gets fixed.
• ☐ Handover report (if there is one):

HANDOVER REPORT
Date: 31 May 2026
Client: [You]
Contractor: [Contractor]
Work: Kitchen renovation

Defects noted:
1. East wall — paint is peeling in the corner, needs touching up.
2. Tiling between the sink and the units has uneven grout lines.

Status: Accepted with reservations. Contractor agrees to fix the above defects by 7 June 2026.

• ☐ Both sides sign (even a text will do: "Confirming the defects noted above — I'll get them fixed.")

MISTAKE #5: Undocumented changes to the contract

What happened: The contract said: kitchen renovation, PLN 50,000. Partway through, you said "let's also replace the top cupboards" (which wasn't in the contract). The contractor said "that'll be extra", you said "ok, how much?" He said "PLN 5,000", you agreed.

Now the final invoice shows PLN 50,000 + PLN 5,000 = PLN 55,000. You say: "That was included!" He says: "No, that was extra."

Why this is a mistake: Every change to the contract is effectively a new agreement. Without paperwork, it's a dispute waiting to happen.

What to do:

• ☐ Put every change in writing — text message, email.
• ☐ Example:

Email: "As discussed, you'll also replace the top cupboards (brand XX, grey) — additional cost PLN 5,000 (VAT included). New total contract price: PLN 55,000. This will appear on the final invoice. Please confirm."

Contractor: "Confirmed."

Now you have proof.

MISTAKE #6: Not clarifying who's responsible for materials — client or contractor

What happened: Complaint: "Your tiles are rubbish, they cracked within a month." Contractor: "But you bought those tiles — I never ordered them. I was paid for labour, not materials."

You don't know who's on the hook here — the contractor, you, or the tile supplier.

Why this is a mistake: Responsibility for materials needs to be spelled out clearly in the contract. Otherwise, it's very hard to prove after the fact.

What to do:

• ☐ Be explicit in the contract about who supplies the materials:
• Option 1: "Contractor supplies materials (included in the PLN 50,000 price)" — the contractor is responsible for quality.
• Option 2: "Client supplies materials — contractor only fits them" — you're responsible for the quality of the materials.

• Option 3: "Contractor sources and orders materials, cost is 30% of the contract price (PLN 15,000), the rest is labour" — a mixed arrangement. Set out clearly who's responsible for what.

• ☐ If you bought the tiles yourself — make sure the contract states: "Client supplies materials, contractor fits them only. Responsibility for defects in materials lies with the client/materials supplier, not the contractor."

MISTAKE #7: Not knowing whether the matter is "consumer" or "business"

What happened: You hired a contractor for a renovation. You assumed you had full consumer protection (right to cancel, compensation without needing to prove much, a faster process). But it turns out the contractor is a registered company, and you run your own business. The matter is now business-to-business — different procedures, different deadlines, different rights.

Why this is a mistake: If the matter is B2B, consumer protections don't apply. Or the other way round — you might think you have no protection when in fact you do, if you genuinely are a consumer.

What to do:

• ☐ Question #1: Am I a consumer or a business?
• Consumer: a private individual, renovating a home you personally live in (not a rental or investment property).

• Business: you run a company, and this renovation is for a holiday let, an office, or an investment property.

• ☐ Question #2: Is the contractor a private individual or a company?

• Sole trader (an individual registered for self-employment, JDG) — either route may apply.

• Registered company (e.g. limited company, Sp. z o.o.) — this is B2B and more formal.

• ☐ If you're a consumer dealing with a company — you have broader rights (cancellation, statutory complaint rights, access to the consumer ombudsman).

• ☐ If you're a business dealing with a company — general civil/commercial rules apply, with no consumer protection.

Tip: If you're unsure, get an initial consultation with a lawyer (often free) before you sign anything.

MISTAKE #8: No written record of communication (everything by phone or in person)

What happened: You say: "Can you get it done quicker, I've got kids at home." He texts back: "Ok, I'll speed it up." Then he falls behind schedule, you say "we agreed you'd speed things up", he says "I never agreed to that."

Why this is a mistake: In court, what matters is evidence. A text or email counts. "I remember him saying so" does not.

What to do:

• ☐ Text after every verbal conversation: "Confirming what we discussed today — you'll work weekends to finish by 31 May. Agreed?"
• ☐ Follow up in-person meetings with a summary email at the end of the day.
• ☐ Avoid phone calls where possible — and if you do call, follow up with a text: "Confirming our phone call at 3pm…"

MISTAKE #9: Waving away "minor" defects with nothing in writing

What happened: You notice a small crack in a corner, but you shrug: "Well, who's going to see that?" You tell the contractor: "Don't bother fixing it, leave it." A month later the crack has spread and the wall starts to give way. You call the contractor: "This was your fault!" He says: "You told me it was fine!"

Why this is a mistake: If you say something's "fine", you've effectively accepted it. It's hard to argue later that it was actually his defect.

What to do:

• ☐ Always distinguish between:
• A defect you accept (and won't pursue a claim over) — photograph it and email: "I'm accepting the following defect: [description], as it's minor. I understand I won't be raising it as a claim later. Agreed?"

• A defect you don't accept — insist it's fixed, in writing.

• ☐ If it gets worse (something minor turns into something major) — keep a photo record (photo plus date on your phone equals evidence of when a small crack turned into a big one).

MISTAKE #10: No agreed deadline for the final payment

What happened: The contract said: "Deposit PLN 25,000, balance PLN 25,000 on handover." Work's finished. You're told: "Balance due tomorrow." Tomorrow comes: "Can't do it, give me a week." The contractor waits, you keep delaying, and he starts threatening court action.

Or the other way round: you agreed to "pay on handover", but you found defects and withheld payment. He assumes you're just stalling.

Why this is a mistake: No clear deadline is a recipe for disputes. Sometimes you must pay, sometimes you're entitled to withhold payment because of defects — but without a clear deadline, it's chaos.

What to do:

• ☐ In the contract: "Balance due within 3 days of signing the handover report."
• ☐ If there are defects — you don't have to pay the full amount straight away. But say so clearly: "There are defects I want fixed. Once they're fixed, I'll pay within 3 days."
• ☐ Once handover is complete with no outstanding defects — pay. Don't stall or drag it out.

MISTAKE #11: No expert opinion for serious defects

What happened: You claim: "This wall wasn't poured properly, there are cracks." The contractor says: "That's normal — every poured wall gets minor cracks."

You don't know who's right. Neither does the court, without an expert opinion.

Why this is a mistake: For serious defects in a renovation, you often need an independent expert opinion (a structural engineer or qualified tradesperson). Without one, it's your word against his.

What to do:

• ☐ For "major" defects — hire an independent expert (cost roughly PLN 500–2,000).
• The opinion becomes evidence: "Cracks of this type indicate inadequate levelling."
• ☐ Keep the report — it will serve as evidence in court.
• ☐ Only commission an opinion if there's a genuine defect — don't get one "just in case", as it can undermine your credibility.

Checklist: before you sign a contract

• ☐ Get the contract in writing (text, email, or a document).
• ☐ It should cover: scope of work, price, timeline, deposit, terms.
• ☐ Photos of the starting condition — saved and dated.
• ☐ Clarity on who supplies materials and who's responsible for them.
• ☐ Clarity on whether it's a consumer or B2B matter — and what that means.
• ☐ Every contract change confirmed in writing — a text with confirmation.
• ☐ Document everything — emails, texts, photos, invoices.

Checklist: during the renovation

• ☐ Photograph progress as it happens.
• ☐ Put every conversation in writing — texts, emails (even after a verbal chat, follow up with a text).
• ☐ Never accept defects with no reservations — always "accepted with reservations" or "will accept once fixed".
• ☐ Photograph defects — as soon as you spot them.
• ☐ Confirm every additional cost in writing, with the contractor's acknowledgement.

Checklist: at handover

• ☐ Walk through every room, taking photos — every angle.
• ☐ Handover report (even an informal one, by text).
• ☐ Always note reservations — never sign off "no reservations" if something's not right.
• ☐ Photograph defects — before they're fixed.
• ☐ Final payment — only once defects are resolved (or as set out in the contract).

Related articles:

• Contractor won't fix defects — when should you send a formal demand letter?
• How to put together an evidence pack for a dispute with a company?
• Company ignoring your complaint — when should you move to a formal demand letter?

Content last reviewed: 26 June 2026.