Intermediate

Perfect Completion & Biennial Warranty: Complete Guide

12 min read

You’ve just had your home handed over, the completion certificate is signed, and you think the “building site” chapter is closed. Not so fast. For the first two years after handover, you benefit from two powerful but often overlooked legal shields: the garantie de parfait achèvement (perfect completion warranty, 1 year) and the garantie biennale de bon fonctionnement (biennial warranty, 2 years). Unlike the décennale warranty which targets major structural defects, these two warranties cover everything else — from hairline cracks in partition walls to stuck roller shutters and faulty taps. This guide explains how to use them to the fullest so that every defect is repaired at the contractor’s expense.

Note: These warranties are grounded in French law (Code civil, articles 1792-3 and 1792-6). They apply specifically to construction projects carried out in France and governed by French law.

THE 3 POST-HANDOVER WARRANTIES Perfect Completion - Biennial - Decennale Handover D 1 year 2 years 10 years PERFECT COMPLET. 1 1 year - EVERYTHING covered Cosmetic, finishes, equipment, defects, snags from the certificate No minimum severity threshold BIENNIAL WARRANTY 2 2 years - Separable equipment Shutters, taps, MVHR, radiators, boiler, motorised units Removable without touching the structure DECENNALE WARRANTY — 10 YEARS Structural integrity or unfit for purpose (non-separable elements + structure) KEY DATES TO REMEMBER D+10 months: final GPA audit D+22 months: final biennial audit

The Perfect Completion Warranty: your total safety net for 1 year

What is it?

The garantie de parfait achèvement (GPA) is codified in article 1792-6 of the French Code civil. It obliges the contractor to repair all defects reported by the client (maître d’ouvrage):

  • Those listed as snags (réserves) in the handover completion certificate
  • Those that appear within the year following handover and are notified by recorded delivery letter

This is the broadest warranty that exists: no minimum severity threshold. Whether it’s a partition crack, a door that won’t close properly, a cracked tile or a badly fixed socket — everything qualifies.

What it covers in practice

Type of defect Concrete example Covered by the GPA?
Cosmetic defects Peeling paint, uneven render Yes
Poor finishes Missing tile grout, loose skirting board Yes
Faulty equipment Socket that doesn’t work, boiler poorly set Yes
Badly fitted joinery Window that won’t close, door that sticks Yes
Structural defects Load-bearing wall crack, roof leak Yes (and also décennale)
Defects listed at handover Any snag itemised in the completion certificate Yes
Normal wear and tear Scratched floor after 8 months of use No
Damage caused by occupant Tile cracked by heavy furniture No

Tip — The GPA is your best weapon during the first 12 months. Don’t wait until the last minute: as soon as you notice a defect, even a minor one, notify the relevant contractor by recorded delivery letter with acknowledgement of receipt. A simple text or email has no legal value in the event of a dispute. Keep a defect log and do a full walk-through of the house at 1 month, 6 months and 11 months.

Snags at handover: the starting point

On handover day, you sign a completion certificate (procès-verbal — PV) listing all snags — defects visible on the day. This is the founding document of the GPA:

  1. Snags listed in the PV → the contractor has an agreed timeframe (usually 90 days) to remedy them
  2. No snag listed = acceptance → visible defects not listed are deemed accepted
  3. Unresolved snags → you can withhold the 5% balance (the “retention”) until they are remedied

Warning — If the contractor fails to clear snags within the agreed timeframe, you can have the work done by another professional and claim reimbursement. However: keep proof of the formal notice that went unheeded (recorded delivery letter + reasonable deadline) before bringing in someone else. Without this proof, you risk being unable to claim against the original contractor.

The 5% retention

When signing the building contract, it is common to provide for a 5% retention (retenue de garantie) on the total amount. This mechanism, governed by French law n°71-584 of 16 July 1971, protects you:

  • You withhold 5% of the price until all snags are cleared or the one-year deadline expires
  • If all snags are resolved, you release the balance
  • If snags remain, you retain the corresponding sum and lodge it with a third party (usually the notaire or the Caisse des Dépôts)

Conseil

Who is bound by the GPA?

The GPA falls on the contractor who carried out the works. Not the architect, not the project manager, not the materials supplier. It is a personal liability of the executing company.

In self-build, this means:

  • Lots entrusted to tradespeople are covered by each tradesperson’s GPA
  • Lots you carried out yourself are not covered — you cannot sue yourself
  • Defective materials that you installed yourself fall under the manufacturer’s warranty, not the GPA

Best practice — Before paying the final balance to a tradesperson, insist on written confirmation that all snags have been cleared. A simple “it’s all done, I’ve fixed everything” over the phone is not enough. Carry out a joint inspection on site and sign a snag clearance document that is dated and co-signed by both parties.

The Biennial Warranty: 2 years for equipment

What is it?

The garantie biennale (or garantie de bon fonctionnement — warranty of good working order) is codified in article 1792-3 of the French Code civil. It covers separable equipment (éléments d’équipement dissociables) — those that can be removed, replaced or repaired without touching the main structure — for 2 years from handover.

Separable vs non-separable: the key distinction

This is the boundary between the biennial warranty and the décennale. An item of equipment is separable if it can be removed without damaging the building fabric. It is non-separable if its removal would damage the structure.

EQUIPMENT: SEPARABLE vs NON-SEPARABLE The boundary between biennial (2 years) and decennale (10 years) SEPARABLE — BIENNIAL 2 YEARS Roller shutters Removable, motor replaceable Taps, mixer taps Unscrewable, standard fittings MVHR, extract fans Unit and vents replaceable Wall-mounted radiators Wall-fixed, can be unhooked Boiler, hot water cylinder Pipe-connected, not cast into structure NON-SEPARABLE — DECENNALE 10 YRS Underfloor heating Cast into the concrete slab Joinery sealed in masonry Integrated into the brickwork Tiles bedded in mortar screed Set in the screed, cannot be removed Masonry fireplace Integral part of the structure Concealed pipework Buried in walls or slabs SIMPLE RULE: can it be removed without breaking the structure? YES → Separable → Biennial 2 years NO → Non-separable → Decennale 10 years
Equipment Separable? Applicable warranty
Roller shutters Yes Biennial (2 years)
Taps, mixer taps Yes Biennial (2 years)
Wall-mounted radiators Yes Biennial (2 years)
MVHR/extract fans Yes Biennial (2 years)
Boiler, hot water cylinder Yes Biennial (2 years)
Intercom, doorbell Yes Biennial (2 years)
Motorised garage door Yes Biennial (2 years)
Tiles bonded to floating screed Yes Biennial (2 years)
Underfloor heating cast into slab No Décennale (10 years)
Joinery sealed into masonry No Décennale (10 years)
Tiles bedded in mortar screed No Décennale (10 years)
Masonry fireplace No Décennale (10 years)

Question

What the biennial warranty covers in practice

The biennial warranty covers malfunctions of separable equipment. In practice:

  • A roller shutter that no longer rises or descends crookedly
  • An MVHR unit making abnormal noise or no longer extracting
  • A radiator that doesn’t heat up or leaks at a joint
  • A switch or socket that no longer works (where the equipment itself is at fault, not the embedded wiring)
  • A hot water cylinder losing pressure or not heating
  • Joinery (windows, doors) whose opening/closing mechanism is faulty

Tip — The biennial warranty only covers functional defects, not normal wear and tear or damage caused by misuse. If your roller shutter fails at 18 months because you force it daily when it is blocked by an obstacle, that is not biennial warranty territory. However, if it fails because the motor was undersized or poorly installed, it is covered.

Who is liable?

As with the GPA, the biennial warranty falls on the contractor who supplied and installed the equipment. It is a presumption of liability: you do not need to prove their fault, only the malfunction.

In self-build:

  • Equipment installed by a tradesperson → that tradesperson’s biennial warranty
  • Equipment you installed yourself → only the manufacturer’s warranty (often also 2 years, but contractual) protects you
  • Equipment you supplied, installed by a tradesperson → the biennial warranty covers installation defects, not material defects

How to activate these warranties: step by step

Step 1: identify the right warranty

flowchart TD A{When did the\ndefect appear?} -->|Before or during\nhandover| B{Listed in\nthe snag list?} B -->|Yes| C[Perfect Completion\nWarranty\nHandover snags] B -->|Not visible\non the day| D{Appeared within\n12 months?} A -->|After\nhandover| D D -->|Yes| E{Nature of\nthe defect?} D -->|No, between\n1 and 2 years| F{Separable\nequipment?} D -->|No, after\n2 years| G{Structural\nintegrity or\nunfit for purpose?} E -->|Any defect\nno threshold| H[Perfect Completion\nWarranty\n1 year] F -->|Yes| I[Biennial\nWarranty\n2 years] F -->|No| G G -->|Yes| J[Decennale\nWarranty\n10 years] G -->|No| K[No applicable\nlegal warranty] style A fill:#0F4C81,stroke:#0F4C81,color:#fff style B fill:#0F4C81,stroke:#0F4C81,color:#fff style C fill:#56C6A9,stroke:#56C6A9,color:#fff style D fill:#0F4C81,stroke:#0F4C81,color:#fff style E fill:#0F4C81,stroke:#0F4C81,color:#fff style F fill:#0F4C81,stroke:#0F4C81,color:#fff style G fill:#0F4C81,stroke:#0F4C81,color:#fff style H fill:#56C6A9,stroke:#56C6A9,color:#fff style I fill:#F58220,stroke:#F58220,color:#fff style J fill:#6B5876,stroke:#6B5876,color:#fff style K fill:#CD212A,stroke:#CD212A,color:#fff

Step 2: notify the contractor

Whether for the GPA or the biennial warranty, the procedure is the same:

  1. Document the defect: dated photographs, precise description
  2. Send a recorded delivery letter with acknowledgement of receipt to the contractor describing the problem, the date it appeared and citing the applicable legal article (1792-6 for the GPA, 1792-3 for the biennial warranty — these are French law references)
  3. Set a reasonable repair deadline (15 to 30 days depending on urgency)
  4. Keep a copy of everything: letter, acknowledgement, photos, correspondence

Step 3: in case of refusal or inaction

If the contractor does not respond or contests:

  1. Formal notice by recorded delivery letter (reminder of legal obligations + new deadline)
  2. Mediation via a consumer mediator (free, mandatory before court action in France)
  3. Emergency injunction (référé) at the civil court to obtain a judicial expert report and/or repairs under penalty
  4. If the contractor has gone bankrupt, direct action against their insurer (which is why you keep the décennale and public liability certificates)

Warning — Warranty deadlines are absolute. If you notify a defect at month 13, the GPA has expired and you can no longer invoke it. You still have the biennial warranty (if separable equipment) or the décennale (if serious defect). This is why it is vital to carry out a full home audit at month 10-11 so nothing slips through before the deadline.

The warranty timeline: don’t miss a single deadline

Here is the standard timeline to follow after handover:

Milestone Action Warranty concerned
Day 0 Handover with detailed completion certificate + snag list GPA (start of deadline)
D + 8 days Sending supplementary snags if handed over without a list (art. L231-8 CCH for CCMI contracts — French law) GPA
D + 1 month First full walk-through, test all equipment GPA
D + 3 months Check after first heating cycle/season GPA + biennial
D + 6 months Inspect sealants, paintwork, tiles after initial settlement GPA
D + 10-11 months Full audit — last chance to notify under GPA GPA (final window)
D + 12 months GPA expires — release 5% if all snags cleared End of GPA
D + 18 months Test all equipment before biennial expires Biennial
D + 22-23 months Final audit — last possible notification under biennial Biennial (final window)
D + 24 months Biennial warranty expires End of biennial

Best practice — Set calendar reminders at D+1 month, D+6 months, D+10 months (final GPA walk-through), D+18 months and D+22 months (final biennial walk-through). This is the simplest method to ensure no defect slips through before the deadlines expire.

The self-build special case

In pure self-build (you do everything yourself), the situation is simple and harsh: you have neither a GPA nor a biennial warranty on your own work. You cannot sue yourself.

But in mixed self-build (the most common scenario), the situation is more nuanced:

What is covered

  • Lot entrusted to a tradesperson (e.g. roofing, plumbing, electrics) → GPA + biennial + décennale from that tradesperson
  • Partial subcontracting (e.g. the tradesperson installs a boiler you purchased) → the installation is covered by the tradesperson’s biennial warranty, not the equipment itself

What is not covered

  • Your own work: no legal warranty; only the manufacturer’s warranty on materials applies
  • Equipment you supplied and a tradesperson installed: if the defect comes from the equipment itself, the tradesperson’s biennial warranty does not apply

Tip — In self-build, the winning strategy is to entrust critical technical lots to insured professionals: foundations, frame, roof, electrics, plumbing. Keep the finishing work for yourself (painting, tiling, fit-out) where the warranty stakes are lower. This maximises your GPA + biennial + décennale coverage on the most costly items to repair.

Many self-builders confuse legal warranties (GPA, biennial, décennale) with commercial/manufacturer’s warranties.

  Legal warranty (GPA/biennial) Manufacturer’s warranty
Source French Code civil (statute) Manufacturer’s contract
Mandatory Yes, automatic No, voluntarily offered
Liable party The contractor who installed The product manufacturer
Duration 1 year (GPA) or 2 years (biennial) Variable (2, 5, 10, 25 years…)
Condition Notification by recorded delivery Per manufacturer’s T&Cs
Applies in self-build Only on lots entrusted to a professional Yes, even if you install yourself

The manufacturer’s warranty is complementary but never replaces the legal warranties. And vice versa: a tradesperson’s GPA does not cover a manufacturing defect in a material you supplied.

Official resources

To complete this guide, also read our articles on the décennale warranty, the DAACT completion declaration and site insurance and public liability.

Checklist

Checklist: making the most of the GPA and biennial warranties

  • Handover completion certificate drawn up with detailed snag list
  • Dated photographs of all defects noted
  • Snags notified by recorded delivery letter to each contractor
  • 5% retention provided for in the contract
  • Full walk-through of the house at D+1 month
  • Inspection after first heating cycle (D+3 months)
  • Check sealants and finishes after settlement (D+6 months)
  • Final GPA audit scheduled at D+10-11 months
  • All equipment tested individually (shutters, MVHR, hot water, sockets)
  • Public liability and décennale certificates from each tradesperson archived
  • Calendar reminders set for key deadlines
  • Biennial audit scheduled at D+22-23 months
  • Snag clearance formalised in writing and co-signed
  • 5% balance released only after full clearance of all snags

The perfect completion and biennial warranties are your first lines of defence after handover. They don’t last long — 1 year and 2 years respectively — but they cover everything, including minor defects that the décennale would ignore. The key is rigour: note, photograph, notify by recorded delivery, and above all don’t let deadlines slip. A home properly handed over and carefully monitored during its first two years is a home that ages well.