BienCheck pillar guide
Property buying pitfalls and how to dodge them
Written by Mathieu Delranc
Founder of BienCheck · View author profile
Buying a property means signing a cheque that binds you for 20 years. The pitfalls aren't exotic edge cases, they hide in the things you don't think to ask. A buried HOA minute, a crack painted over the day before the viewing, a sloppy suspensive clause, a friendly EPC, and tens of thousands of euros switch sides.
This guide gathers the pitfalls we see most often in BienCheck reports, sorted by step. Viewing, pricing, financing, contract, HOA, surveys, planning. For each one, the signal you should've caught and the concrete fix to run before you sign.
Viewing pitfalls
The viewing is staged. Tidy, fragranced, lit. The agent talks so you don't get the time to look. Leave with photos, video, and a list of questions that didn't get a clean answer.
- Patchy fresh paint. A wall freshly painted in one corner is suspicious. Check behind furniture and at the base of walls, where damp rises.
- Well-placed rugs and furniture. A rug on parquet often hides a stain. A wardrobe against an outside wall often hides a crack. Ask to look behind.
- Picked viewing slot. Insist on a second viewing at a different time, ideally evening and weekend. You'll see the real light and hear the real noise.
- Neighbour and street noise. Kill the background music. Open the windows. Listen for the street, the neighbours, the lift, the shared boiler.
- Plumbing and drainage. Open every tap at once. Flush the loo. Soft pressure or slow drainage, that's a red flag.
Pricing pitfalls
The asking price isn't the market price, it's what the seller hopes for. With no real data in hand, you negotiate blind. With DVF, you know exactly what comparable properties on the street actually sold for over the last 12 months.
Beware of listings sitting online a long time without a drop, or fresh listings dressed up as rare. In both cases, the price is probably off, up or down for the wrong reasons.
Survey and EPC pitfalls
The EPC is mandatory but not infallible. Depending on the surveyor, the same flat can shift from E to D. Check the date, the surveyor's name, and whether the method fits the property.
Other diagnostics (asbestos, lead, electrics, gas, termites, risks report) aren't an expert opinion. They flag presence or non-compliance, not the size of the works. A non-compliant electrical install can cost €800 to €12,000 depending on scope.
HOA / condo pitfalls
The HOA is blind spot number one. You buy a flat, but you also buy a share of every problem. A roof redo voted next week can turn a love-at-first-sight into a money pit.
- Last 3 years of HOA minutes. Read them end to end. Look for voted works, deferred works, disputes, lawsuits, arrears.
- Maintenance log and global survey. Buildings over 15 years old must have a global technical diagnostic. Ask for it.
- Real charges vs advertised. Compare the listed charges with the last 2 years of statements. Gaps of 30 % aren't rare.
- Works fund and cash position. An empty fund in an ageing building means one-off call-ups coming.
- Live disputes. Conflict with a co-owner, syndic, neighbour, town hall. All in the minutes.
Planning pitfalls
The neighbourhood you see isn't necessarily the one you'll live in 5 years from now. The local plan and the council's projects can turn an open view into a building site, or a car park into a tower.
Visit the town hall or browse the local plan online. Check future development zones, planning permits nearby, industrial sites, future roads. A tram line 100 m away can lift value, but a roundabout 50 m away can sink it.
Contract pitfalls
The preliminary contract binds you. Once signed, you only walk away through the 10-day cooling-off period or via a well-drafted suspensive clause. Never sign a contract you've seen for the first time the same day.
- Precise mortgage suspensive clause. Amount, max rate, term, number of banks to approach. A vague clause and the seller can challenge your refusal.
- Dated and pre-dated statement. In a condo, these list charges and voted works. Demand them before signing, not after.
- List of fixtures and fittings. Fitted kitchen, AC, alarm, solar panels. List everything that stays, written and signed.
- Extra suspensive conditions. Planning permit, no easement, planning consent. Add the ones that protect your project.
- Reasonable deposit. 5 % max, held by the notary. Refuse any direct deposit to seller or agency.
Mortgage pitfalls
Mortgage refusals are more common since the regulator tightened (35 % debt-to-income cap, insurance included). Signing a contract without a validated simulation from a broker or your bank is a real risk.
Polish your file before signing. Three last payslips, two last tax returns, three last bank statements with no overdraft. An active consumer loan can sink your mortgage, clear it if you can before submitting.
Notary pitfalls
The seller's notary isn't your enemy, but isn't your ally either. You can have your own notary at no extra cost, fees split between the two offices. Do it, especially on a complex condo or a risky property.
On signing day, new items sometimes surface. Mortgage status, easements, cadastral changes. Don't sign under pressure. Ask to read at home if anything bothers you.
The 12 most expensive mistakes
The pitfalls we see again and again, report after report.
- 1
Only viewing once
A 30-minute crush often ends in regret. Insist on a second viewing at a different time.
- 2
Skipping HOA minutes
If the seller won't share the last 3 AGMs, walk away. The building's past lives in those papers.
- 3
Trusting the EPC blindly
Check the date, surveyor's name, and consistency with actual energy bills.
- 4
Underestimating voted works
An €80,000 facade redo voted before your purchase is on you if you sign after the vote.
- 5
Signing with a vague suspensive clause
Without a detailed mortgage clause, a refusal can cost you 5 to 10 % of the price.
- 6
Missing real charges
The ad says €1,800 a year, the reality is €2,600. Check the statements.
- 7
Skipping the local plan
A live planning permit 50 m away is public. The town hall tells you for free.
- 8
Buying without a mortgage simulation
An unvalidated file is a coin flip with your deposit.
- 9
Skipping the risks report
Flood, clay, seismic, radon, industrial. The risks report is free, read it.
- 10
Believing the seller on works
Ask for invoices, decennial warranties, insurance certificates.
- 11
Negotiating without data
With no DVF, you negotiate on vibes. With numbers, you negotiate on price.
- 12
Signing at the notary under pressure
A new detail on the day is a legitimate reason to delay. Never sign what you haven't re-read.
What a missed pitfall costs
Orders of magnitude for the main pitfalls, observed in BienCheck reports on the French market.
| Pitfall | Typical cost | Why |
|---|---|---|
| Voted HOA works not anticipated | €5,000 to €60,000 | Facade, roof, lift, insulation. Buyer after vote pays. |
| F or G EPC not negotiated | €20,000 to €70,000 | Energy works to exit the energy sieve and be allowed to let. |
| Non-compliant drainage | €6,000 to €15,000 | 12 months after sale to bring up to spec. |
| Mortgage refusal with weak clause | 5 to 10 % of price | Lost deposit if the suspensive clause is vague. |
| Missed clay shrinkage | €15,000 to €60,000 | Foundation cracks in strong clay zones. |
| Overpaying vs market | 3 to 15 % of price | Gap between asking and local DVF, lost at resale. |
| Undetected easement | Varies | Way, view, utility. Can kill an extension project. |
| Underestimated entry works | €8,000 to €50,000 | Kitchen, bathroom, windows, paint. Get quotes. |
| Uncovered hidden defect | €10,000 to €100,000 | If the exclusion clause is badly negotiated, recourse is hard. |
How BienCheck helps
BienCheck is built to surface exactly these pitfalls, without you needing to be an expert.
Free analysis right away
Score out of 100, strengths, alerts, price coherence with your local market.
Full Premium report
Deep read, negotiation margin, real cost over 10 years, PDF export.
See a sampleNatural and industrial risks
Flood, clay shrinkage, seismic, radon, ICPE industrial sites at the exact address.
See risksDetailed EPC analysis
Projected heating cost, renovation scenarios, Climate Law alerts.
Understand the EPC
Pitfalls FAQ
What's the most common pitfall?+
Signing without reading the HOA minutes for a flat, or without checking the local plan for a house. Those are the two biggest blind spots.
Can you cancel a contract after signing?+
Yes, within 10 days of notification, no reason needed. After that, only via an unmet suspensive clause (mortgage refused, permit not granted).
How do you protect against hidden defects?+
Most contracts include an exclusion clause. Get a building pro to walk the property before signing, €300 to €600 well spent.
Can an EPC be wrong?+
Uneven, more like. Depending on the surveyor, a full class gap is possible. Cross-check with the seller's actual energy bills.
Should you bring your own notary?+
Yes, especially on a complex condo or risky property. No extra cost, fees split between the two offices.
What if the condo has heavy arrears?+
Ask the syndic for details. Above 8 to 10 % arrears, the condo is fragile and charges can climb to plug the hole.
Is a vague mortgage clause valid?+
Legally yes, but the seller can challenge your refusal. Force amount, max rate, term, number of banks.
How do you check upcoming HOA works?+
Last 3 years of minutes, multi-year works plan, works fund, global technical diagnostic for buildings over 15 years.
Is a listing sitting 6 months online a bad sign?+
Often yes. Either the price is too high, or the property has a defect previous buyers found. Ask why.
Can you renegotiate after the contract?+
Very hard, unless an extra diagnostic (asbestos, termites) reveals an unmentioned defect. Renegotiate before signing.
How do you avoid the mortgage trap?+
Validate your simulation with a broker or your bank before making the offer. Clear consumer loans if you can.
What's a mortgage status and why read it?+
It lists mortgages and liens on the property. The notary pulls it, you should read it before final signing.
What if you spot a pitfall after signing?+
Depending on the case, hidden-defect warranty (2 years), price-reduction action, or recourse against the notary or surveyor. See a specialist lawyer.
How much does a building expert cost for a viewing?+
€300 to €600 for a 1 to 2-hour visit with report. Pays back the moment it dodges a €5,000 pitfall.
Does BienCheck replace a technical survey?+
No, BienCheck cross-references public data and seller info to flag blind spots. An on-site expert still helps on the technical side.
Glossary
- HOA minutes
- Minutes of the condo's general assembly, recording every voted decision.
- Global technical diagnostic
- Mandatory survey for condos over 15 years old.
- Suspensive clause
- Condition that must be met for the sale to complete.
- Dated statement
- Syndic document listing charges, voted works and arrears at sale date.
- Works fund
- Condo's reserve fund, paid into by all co-owners.
- HCSF
- French Financial Stability Board, sets mortgage debt rules.
- EPC
- Energy performance certificate, A to G rating.
- Risks report (ERP)
- Mandatory document listing the risks at the address.
- Hidden defect
- Non-apparent flaw that makes the property unfit for use.
- Decennial guarantee
- Mandatory 10-year warranty covering structural damage.
- Mortgage status
- Document listing mortgages and liens on a property.
- Local plan (PLU)
- Sets building rules plot by plot at the municipal level.
- ICPE
- Classified industrial installation, regulated risk site.
- Clay shrinkage (RGA)
- Ground movement under foundations in clay zones during droughts.
- SPANC
- Public service controlling individual drainage installs.
- Preliminary contract
- Pre-contract binding buyer and seller.
- Cooling-off period
- 10-day window after contract notification to withdraw without reason.
- Easement
- Right a neighbour or public body exercises on land.
- Géorisques
- Public portal cross-referencing natural and technological risks at an address.
Going further
A few BienCheck resources that complement this guide.
- Buying a houseFull check-list for a house.
- Buying an apartmentThe pillar guide for flats.
- Negotiating a propertyEvery buyer-side negotiation lever.
- Sale agreementClauses, deposit, cooling-off, what to master.
- Understanding a condoAGM minutes, works fund, charges.
- Understanding the EPCLabels, costs, Climate Law, works.
- Natural risksClay, flood, seismic, radon, industrial.
- DVF dataActual transactions published by the State.
From guide to action
Guides explain. Tools decide. Run the analysis on your property or compare your options in two clicks.
Property analyser
Run a full analysis on a property: price, risks, EPC, negotiation room.
Analyse a propertyProperty comparator
Compare two or three properties side by side on the criteria that actually matter.
Compare propertiesRental yield calculator
Work out the real net yield of a buy-to-let in seconds.
Calculate the yieldSample report
See what a full BienCheck report looks like before you commit.
See an examplePricing
Pick the plan that fits your project: free, Premium or pack.
See pricingReady to dodge the pitfalls?
Run your free BienCheck analysis. In minutes, you'll see the pitfalls waiting on this specific property.
Analyse a property for free