Document Checklist for a Case Against a Polish Property Developer

You're gearing up for a dispute with a Polish developer over defects in your flat, but you're not sure exactly what you'll need. Rather than panicking and wasting time, work through this practical checklist — it covers everything that might be useful at every stage: from the first complaint, through mediation, right up to court. You won't need every item in every case, but it's worth knowing what to start gathering now, before something gets lost or you forget the details.

This material is general information, not legal advice. Everything depends on the contract, the evidence and the circumstances — and on whether the matter is a consumer case, a civil case, or a business-to-business one. If you need advice or representation, the matter should be assessed by a qualified Polish lawyer or specialist. Twoja Sprawa helps you organise the documents for that assessment.

Documents to gather straight away (before you look for help)

Before you call a lawyer, gather at least these basics:

1. Contract and terms

☐ The pre-sale agreement (umowa deweloperska — the developer's contract, or the final sale contract) — the complete text, all pages, both parties' signatures
☐ Annexes to the contract — any changes, deadline extensions, changes to terms
☐ Technical specification — the specification of the unit, and any attachments giving parameters (e.g. floor area, layout, materials)
☐ Draft technical report, if there was one — describing the planned standard of materials/workmanship
☐ Mortgage/financing conditions — if they included reservations about defects

Where to look: with the notary (a civil-law notary — notariusz, not the same role as a UK notary public — keeps a copy of the deed), with the developer's office (they can issue a copy), or in your own files — you always receive a copy on signing.

2. Proof of payment

☐ Proof of paying the full purchase price — bank transfers (statements or bank confirmations), cash payments (receipt), mortgage (loan agreement plus a statement confirming repayment)
☐ Receipts/invoices for extras — if you bought add-ons (parking space, storage unit, upgraded finishes) — useful evidence for assessing the total contract value
☐ Confirmation of payments into the Developer Guarantee Fund (DFG) — Poland's statutory buyer-protection escrow scheme — if payments were made into it, keep the account number
☐ Mortgage documents — if a mortgage was a condition of the purchase, they sometimes contain clauses relating to the property's quality

Where to look: your bank account, online banking, correspondence from the bank, letters from the developer's office.

3. Documents relating to the defects themselves

☐ Handover report (protokół odbioru) — the document signed by you and the developer on the day the flat was handed over (sometimes a few days before completion); each side should have a copy
☐ Annex to the handover report — the list of defects you noted on handover day
☐ Photos/video from handover day — taken while walking through the flat, showing the defects (with a date on the file!)
☐ Notes from handover day — your own notes on times, defects, and the conversation with the developer — dated
☐ Photos of defects taken later — if defects worsened or you noticed them afterwards (always dated; a smartphone photo's EXIF metadata is usually enough)
☐ Video walkthrough of the flat — if you made one; useful for showing the full scale of the problem

Where to look: your copy of the handover report (should be in your document folder), your smartphone (photos/video in the gallery), Google Drive/iCloud, a USB drive.

Documents relating to correspondence with the developer

Collect all of it — it will speak to the developer's remedial efforts and their responses:

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☐ Demand letters / requests to fix defects — every letter you sent the developer (email, recorded-delivery post, text message, WhatsApp) demanding repairs; note the date sent and the method (email is not the same as a text message, which is not the same as recorded post)
☐ Emails from the developer — every reply in which they:
acknowledge the defects,
reject the defects,
give a repair timeline,
give reasons for any decision
Note the date on every one.
☐ Recorded-delivery letters — if you sent demand letters by recorded post, keep the delivery confirmation slip (the equivalent of Poland's "blue confirmation of receipt").
☐ Text messages, WhatsApp messages — if you discussed the defects by chat (sometimes useful; take screenshots that clearly show the date).
☐ Notes from meetings/phone calls — if you met the developer and made a note or recording (with the other party's knowledge); sometimes the developer sends a written confirmation: "Following our call on 15 May, we confirm that…".
☐ Letter from the developer refusing to accept the defects — if they formally rejected your complaints (this date matters for calculating time limits).

Where to look: your email inbox, WhatsApp (export the chat), text messages (take screenshots), your own notes, your archive of recorded-delivery post.

Documents relating to repair of the defects

Gather this without delay, before the defects are fixed (it will be useful later as evidence):

Before the repair

☐ Photos/video of the defects — from different angles, with a ruler or object for scale, dated
☐ Your own inspection notes — e.g. "In the bathroom near the window there is visible plaster cracking, roughly 30cm long, about 5mm deep, damp to the touch"
☐ Medical documentation — if the defects affected your health (e.g. draughty windows → cold → respiratory illness/asthma) — a doctor's note or prescription
☐ Correspondence with the relevant inspectorate — if you reported the defect to the Trade Inspectorate (Inspekcja Handlowa), the building-standards inspectorate (WIIH), or the local council (e.g. an unauthorised structure, works done without permission)

After the repair (or instead of a repair)

☐ Expert surveyor's report — if you instructed a building surveyor to assess the defects; the expert should:
state whether it's a defect or normal wear and tear,
identify the cause (workmanship error, design error, wrong materials),
estimate the cost of repair,
give an opinion on how the defect affects usability,
date the report
☐ Receipts for repairs you paid for yourself — if you fixed something yourself because the developer was dragging its feet:
invoices for materials,
invoices for labour (if you hired a contractor),
the contract with that contractor (if you engaged one)
☐ Photos after the repair — if the developer carried out the repair, photograph the result; if the repair is poor, you'll have evidence
☐ Second handover report — if the developer fixed the defect, you should get a fresh report confirming everything is now in order

Documents for quantifying your losses (damages and compensation)

If you're seeking money on top of the repair itself, gather evidence of your losses:

Direct costs

☐ Hotel/accommodation receipts — if the flat was uninhabitable (flooded, no heating) — payment confirmations from a hotel or guesthouse
☐ Receipts for materials/services — if you bought materials for a temporary fix (e.g. plastic sheeting for a window, temporary lighting)
☐ Extra travel costs — if you had to travel to the flat repeatedly and be present for repairs (relevant if the defects required your presence while you were also working)
☐ Surveyor's fees — how much you paid for the technical report

Indirect losses (harder to prove, but worth trying)

☐ Medical documentation — if the defects caused health problems (e.g. a chronic cough from mould) — a doctor's certificate, prescriptions
☐ School/work records — if a child had to change school because of the flat (relevant only in more complex cases)
☐ Correspondence with the bank — if your mortgage contained a clause about changes in the property's value (banks sometimes require the loan to be reduced if defects have lowered the property's value)

Where to look: your receipts, doctors' certificates, school documents, bank confirmations.

Documents relating to advice and representation

Before you seek help, gather this:

☐ The developer's professional record — ask yourself whether it was licensed to build this type of property, and whether a qualified structural engineer signed off the design (this sometimes reveals procedural failures)
☐ Materials certificates — if the developer promised specific materials (e.g. "Europlex windows"), check whether it actually installed them; the developer's own procurement records can sometimes reveal this
☐ Documents from a court-appointed expert — if you'll need an expert opinion in court, you'll need one appointed by the court (biegły sądowy), not a private one. At this stage, having an agreement with an expert from the official court list is enough.
☐ Competing repair quotes — if you want to argue that the repair could cost something different from what the developer proposed; 2–3 competing quotes can be useful

Organising your documents — practical tips

How to archive everything

A physical folder — a ring binder with dividers by subject: - contract and terms, - proof of payment, - handover reports and photos, - correspondence, - expert opinions, - demand letters and replies.
A digital archive — a folder on your drive or Dropbox: - a scan of the contract (PDF), - screenshots of emails (as dated PDFs), - photos of the defects (in the original file format, not compressed — you may need these for court), - an Excel file with a timeline (date, what happened, who you contacted, the outcome).
Backup — keep a copy on a USB drive or in the cloud (Google Drive, OneDrive) — if a hard drive fails, everything on it is gone.

How to organise your emails

Create a folder in Outlook/Gmail: "Developer case — flat [address]".
Don't delete or archive anything — keep it all visible.
If the case is dragging on, export the whole folder to PDF (usually File → Print → Save as PDF) — that way you have a paper backup too.

Checking yourself: do I have everything?

Before you feel ready to talk to a lawyer, check:

☐ Do I have the original or a certified copy of the purchase contract?
☐ Do I have complete proof of payment (transfers, mortgage)?
☐ Do I have the handover report with the list of defects?
☐ Do I have photos of the defects from handover day, and any taken later?
☐ Do I have the complete email correspondence with the developer?
☐ If I sent demand letters by recorded post, do I have delivery confirmation?
☐ If the developer repaired the defects, do I have photos of the result?
☐ If I instructed a surveyor, do I have their opinion covering the defects and the repair cost?
☐ If I incurred costs (hotel, materials, surveyor), do I have the receipts?
☐ Do I have notes setting out the timeline of events (what happened, what was said, what the outcome was)?

If you can answer "yes" to most of these, you're ready.

What NOT to do with your documents

❌ Don't throw anything away — even small receipts can turn out to be useful.
❌ Don't edit photos — if you change the date, alter the metadata, or adjust the parameters (brightness, contrast), the court may doubt their authenticity. It's better to take a fresh photo of an old printed photo than to edit a digital file.
❌ Don't send originals — always send copies and keep the originals at home (you may need them to make further copies for the court).
❌ Don't rely on memory — always date your documents. The court will ask, "When did this happen?" — without a date it's hard to prove.
❌ Don't put off gathering documents — every day of delay is a risk that something gets lost (an email gets deleted, a photo goes missing, a phone gets replaced).

The most common mistakes when gathering documents

No handover report — if you've never actually seen it on paper (or if only the developer has a copy), request one now. If they stall, that alone is a warning sign.
Undated photos — you take photos, but there's no visible date on the file, so the court won't take your word for when they were taken.
Mixed-up emails — you reply to the developer from different email addresses, so each message ends up in a different thread and the court struggles to follow the exchange. Pick one address for the whole case.
No copy kept of recorded-delivery letters — you send a demand letter but keep no copy for yourself. The court asks: what exactly did you write? You can't show them.
Relying on memory of phone calls, with no notes — a month later you can't remember exactly what was said. Write notes straight after each call: date, time, who said what, what was agreed, the deadline.

Final printable checklist

Print the checklist below and tick items off as you go:

PHASE 1 — Basics (first 2 weeks after discovering a defect) - ☐ Purchase contract (all pages) - ☐ Annexes to the contract - ☐ Handover report - ☐ Photos of defects from handover day (dated) - ☐ Photos of defects taken later (dated) - ☐ Proof of payment (transfers, mortgage, settlement statement)

PHASE 2 — Correspondence (during discussions with the developer) - ☐ Copy of the demand letter for repairs (email/recorded post) - ☐ Delivery confirmation (for recorded post) - ☐ All emails from the developer (dated) - ☐ Notes from phone calls (date, time, content, agreements) - ☐ Text messages / WhatsApp (dated screenshots)

PHASE 3 — After the developer's decision (refusal, or repairs dragging on) - ☐ Surveyor's technical opinion (if you decide to instruct one) - ☐ Receipts for repairs you paid for yourself - ☐ Photos of the repair result (if the developer carried it out — taken by you) - ☐ Receipts for your losses (accommodation, materials, services)

PHASE 4 — Before meeting a lawyer - ☐ Everything from Phases 1–3 in one place (a folder, physical or digital) - ☐ A one-page A4 timeline note

Last checked: 26 June 2026.