Builder Demanding Extra Payment Above the Agreed Price? What Polish Law Says

The renovation is under way, half the flat is torn up, and the builder suddenly announces that "it can't be done for that price" and demands extra payment — sometimes a few thousand złoty, sometimes closer to twenty thousand. The short answer: whether you actually have to pay depends above all on how you agreed to be charged — a fixed price (ryczałt, one lump sum for the whole job) works very differently from a cost-estimate arrangement (kosztorys, billed against an itemised schedule of works and prices). Before you pay or sign anything, ask for the demand in writing, with reasons, and don't make a decision under pressure from "we're walking off site."

This guide is general legal information, not legal advice. How the rules apply depends on your individual circumstances, the wording of your contracts and other documents, and applicable time limits. If you need advice or representation, the matter should be assessed by a qualified Polish lawyer. Twoja Sprawa helps you organise the documents for that assessment.

Key points

• The type of price agreed decides almost everything. Under a fixed price (ryczałt), the builder generally cannot demand a price increase, even if they under-costed the job. Under a cost-estimate arrangement (kosztorys), a price increase is possible, but only within defined limits and rules.
• "Additional works" is not the same as "the same works at a higher price." For work you never ordered and never agreed to, you don't automatically have to pay whatever is being demanded.
• Any change to the scope of works should be agreed — ideally in writing (an addendum, an email, a text message). A verbal "while we're at it, let's also do this" is a direct route to a dispute.
• A threat to walk off site is pressure, not a legal argument. A builder who stops work without justification can themselves become liable for improper performance of the contract.
• Don't pay "just to keep the peace" without a written justification for the demand — a voluntary top-up payment can later be very hard to get back.
• Keep records of everything: photos of the work in progress, correspondence, cost estimates, bank transfers.

Fixed price or cost estimate — this is where every assessment starts

Before deciding whether a demand for extra payment has any basis, work out how you actually agreed the price. In practice there are two main models:

Fixed price (ryczałt) — a single, pre-agreed sum for the entire agreed scope of works ("bathroom renovation for 25,000 PLN"). A fixed price shifts the costing risk onto the builder: if they miscalculated labour or materials went up, as a rule they cannot demand a higher fee. There is a narrow exception: if, due to an extraordinary, unforeseeable change in circumstances, completing the works for the agreed sum would expose the builder to a glaring loss, they may seek a price adjustment — but through the courts, not by issuing an ultimatum on site. An ordinary rise in materials prices usually does not meet that bar.

Cost-estimate price (kosztorys) — the price is derived from a schedule of planned works and anticipated costs (a kosztorys). Here the law does allow adjustments — for example where official prices or rates change during the works, or where work not foreseen in the estimate turns out to be necessary. But even then there are limits: if the builder drew up the estimate themselves, they must notify you promptly of the need for a significant overrun — and you can then withdraw from the contract, paying only for the work already done.

If the contract (or the emails/texts you exchanged) doesn't clearly say which model applies, that is often exactly what the dispute is about — which is why gathering all the correspondence from the negotiation stage matters so much.

Additional works vs. works you ordered — where the line sits

The second common scenario: the builder isn't so much "raising the price" as claiming they carried out additional works beyond the agreed scope. Three situations are worth distinguishing here:

1. Works you ordered — they were in the contract or the cost estimate. You pay the agreed price, not a top-up.
2. Additional works you agreed to — during the job you asked for something extra (e.g. another electrical socket) and agreed a price for it. You do have to pay for this — but only the amount agreed, not whatever the builder works out afterwards.
3. Additional works you never agreed to — the builder expanded the scope on their own initiative and is now presenting a bill. As a rule, you are not obliged to pay for something you never ordered; the builder may try to claim on other grounds (so-called unjust enrichment), but it is for them to prove what was actually done and what it is genuinely worth.

Practical rule: every change of scope = written confirmation (a text or email is enough: "Confirming the addition of X for Y PLN"). The absence of such confirmation counts against whoever is demanding money.

"Pay up or we walk": how to respond to the pressure

This is the most stressful moment, because the builder has the practical upper hand: a half-finished flat and your schedule in their hands. A few ground rules:

• Don't decide verbally, on the spot. Ask for the demand in writing: the amount, how it was calculated, and what it's based on — pricier materials? additional works? a costing error?
• Reply in writing (email is fine): restate the agreed price and scope, ask for the basis of the demand, and note you're open to discussing genuinely additional work — once it's been documented.
• Document the state of the works in case they do walk off site: dated photos and video, room by room, both close-up and wide shots.
• Don't close the door on negotiation. Sometimes part of the demand is fair — paying the disputed portion "under reservation of a right to reclaim," or settling in stages, can beat an all-out war in the middle of a renovation.

If the builder does stop work without justification regardless, they may become liable for damage arising from non-performance or improper performance of the contract — for example, the cost of having another crew finish the job, to the extent it exceeds the remaining agreed price.

When extra payment is actually justified

A demand for extra payment isn't always groundless. Consider paying (once it's documented) where:

• you yourself changed or expanded the scope of works during the renovation — even verbally, if that can be shown;
• the price was cost-estimate-based, and necessary work turned up during the job that couldn't have been foreseen (e.g. hidden wiring that needs replacing once the plaster is stripped) — provided the notification rules were followed;
• the contract contains a price-indexation clause, or expressly allows the price to change in defined situations;
• there has been a genuinely extraordinary change in circumstances (not just ordinary price rises), and the builder is pursuing a settlement or a court claim rather than issuing an ultimatum.

In a consumer–business relationship there is extra protection: terms that let the business raise the price at will, without giving the consumer a right to withdraw, may be an unfair contract term (so-called klauzula abuzywna). In a B2B relationship the protection is weaker — what matters above all is the actual wording of the contract.

Documents and evidence to gather

Common mistakes

• Paying cash "to make it go away," with no receipt and no written demand — later it's hard to prove what you paid for and why.
• Agreeing to scope changes verbally — a month later, no one remembers what was "included" and what was extra.
• Signing an addendum handed to you on site under pressure, without reading it or taking a moment to think.
• Not documenting the state of the works before the builder leaves — afterwards, the dispute over "how much was actually done" becomes your word against theirs.
• Terminating the contract in the heat of the moment, without a written notice and a deadline to remedy the situation.
• Ignoring the whole demand when part of it is actually justified — separate what is genuinely owed from what's been plucked out of thin air.

Step-by-step: what to do

1. Work out the pricing model — go through the contract, the quote and the correspondence: fixed price or cost estimate? What scope of works was actually agreed?
2. Ask for the demand in writing — with the amount, the calculation and the reasoning. Don't decide anything until you have it.
3. Document the state of the works — dated photos/video of every part of the job, before things escalate further.
4. Reply in writing — set out your position: what was agreed, what you accept (e.g. genuine additional works), and what you're refusing and why.
5. Try to reach an amicable settlement — e.g. an independent valuation of the disputed works, staged payments, mediation. As a consumer, you can also get free advice from your local municipal or district consumer ombudsman (rzecznik konsumentów).
6. If the builder walks off site — confirm this in writing and call on them to return to work within a set deadline; if that deadline passes without result, consider your next steps (withdrawing from the relevant part of the contract, completing the job with another crew, claiming the cost difference) — ideally after consulting a lawyer.
7. Gather the full set of documents from the table above — this is the basis for any negotiation and for a possible dispute.

Settling up if the builder has left the site

If the working relationship has actually broken down, the settlement usually covers three elements:

• The value of the work actually completed — as a rule the builder is entitled to payment for what they genuinely and properly completed (in proportion to the agreed price, not according to some figure they invent afterwards).
• Any overpayment on your part — if the deposits you've paid exceed the value of the work done, you can ask for the difference back.
• The cost of finishing and putting things right — if completing the job with another crew costs more than the remaining agreed price, the difference may be a loss you can claim back from the original builder.

The evidence is what matters here: documentation of the state of the works on the day the builder left, a cost estimate for finishing the job, and invoices from the new crew. Also watch the time limits: claims under a contract for specific work (umowa o dzieło) become time-barred two years after the work is handed over (or, if it was never handed over, from the day it was due to be); where the contract is classified as construction works (roboty budowlane), the time limits may run differently.

Frequently asked questions

Under a fixed price, can the builder raise the price at all? As a rule, no — a fixed price means the builder bears the risk of having costed the job incorrectly. The exception is an extraordinary, unforeseeable change in circumstances that would expose the builder to a glaring loss — but even then, a court decides on any price change, not an ultimatum issued on site.

The builder says materials have gone up in price. Is that enough to justify extra payment? Materials simply getting more expensive is usually not enough under a fixed price — that's a normal risk the builder should have priced in. Under a cost-estimate arrangement, an adjustment may be possible on the terms set out in the law or the contract. Always ask for the calculation in writing.

Do I have to pay for additional works I never ordered? You have no automatic obligation to pay the amount demanded for work carried out without your consent. It's for the builder to show that the work was agreed, or genuinely necessary, and what it's actually worth — an independent valuation can help here.

I paid the extra amount under pressure. Can I get it back? That depends on the circumstances — including whether the extra payment had any basis in the contract, and what evidence you have of the pressure and of what was agreed. Recovering money you paid voluntarily can be harder, which is why it's worth stating in writing, before you pay, that you're paying the disputed sum under reservation of a right to reclaim it. A lawyer should assess the specific case.

As a business (B2B), do I have the same rights as a consumer? Not entirely. The rules on fixed price and cost estimates are similar, but businesses don't benefit from full consumer protection, and in B2B contracts the literal wording of the agreement carries much more weight. That makes it all the more important to confirm any change of scope or price in writing.

Legal basis

This guide refers to provisions of the Polish Civil Code on contracts for specific work and construction works (umowa o dzieło and roboty budowlane) — among others, Articles 118, 385¹, 385³, 405, 471, 629, 630, 631, 632 §§1–2, 646 and 647 of the Act of 23 April 1964 – Civil Code (consolidated text: Dz.U. 2026 poz. 795). The "to verify" markers next to individual citations in the text flag statements whose current wording and applicability should be confirmed by a lawyer before publication.

Related guides

• What a good contract with a renovation crew should cover — so you avoid a price dispute next time.
• Renovation with no written contract — how to pursue a claim — when the arrangements were only verbal.
• Delayed home renovation — when you can claim your costs back — if a payment dispute has stalled the works.
• Builder refusing to fix defects — how to prepare a formal demand letter — when quality, not just price, is in dispute.
• All guides on disputes with businesses — the full topic hub.

Have a dispute over extra renovation charges and don't know where to start? Send us the documents relating to your renovation — the contract or record of what was agreed, the cost estimate, and any demands for extra payment — and we'll help you get them organised for a lawyer to assess. Submitting the form does not create a contract and does not commit you to anything.