Do I have to do this even if the job looks fine?

It is worth it. Many defects (air getting through, water on rainy days, a sash that scrapes) only show when you test. Ten minutes on the day save weeks of argument later.

The installer says there is nothing to sign. Now what?

There may be no handover note. Still keep the invoice, the date the work ended and the photos, and write by email what you found.

Can I do the list after the crew has left?

You can, but it is harder: the crew is no longer there to fix things and the proof of the state on the day is weaker. What can only be seen later, like water after rain, tick when it happens.

I lost the window label. Do I lose the warranty?

Not for that reason alone, but the label and the invoice help a lot to prove which window and which glass it is. Photograph the glass and frame labels.

Window installation handover checklist

Check the windows before the crew leaves and before you pay the rest. There are 7 groups and about 30 points, in the order you usually see them. Tick as you check; it is saved on this device. You can copy what is left or print. Free, and nothing leaves your browser.

Why it pays to do this on the day

If the company installs, the law treats the goods as delivered when the installation is finished (Decree-Law 84/2021, article 11(2)). The 3-year legal guarantee counts from that date.
In the first 30 days, if a defect shows up, you can ask straight away for a replacement or to cancel the contract (article 16). After that, the law follows an order: repair or replace first.
A problem noted and photographed on the day, with a date, is much easier to prove than an account months later.

The list

0 of 29 points checked

1. What was agreed

The number of windows and doors installed is the number in the quote.
Check each one: opening type (casement, tilt-and-turn, sliding), sizes, colour and glass.
The extras promised in writing are done: removal of the old windows, rubble, finishing, shutters.
If the quote had separate lines, check line by line.

2. Labels and papers

The window has CE marking and the company can say where the declaration of performance is.
CE marking shows what the manufacturer declared; it is not a quality class. Ask for a copy of the declaration: the European regulation provides for a paper copy on request, but we found no official text that imposes it on the seller.
If the quote promised CLASSE+ windows, each window has its own ID and you can check it on classemais.pt.
Five windows, five different IDs. One ID cannot serve more than one window.
You kept or photographed the glass label.
Glass makers ask for the label and the invoice for the glass warranty (example: Guardian Select).
You received the invoice with your tax number.
Without an invoice it is very hard to prove the purchase and use any warranty.
The warranty is in writing: for the product and for the installation, with duration, what it covers and who gives it.
An extra company warranty does not remove the rights in the law.
You received the use and maintenance instructions, and those for adjusting the hardware.
The law asks for goods to be delivered with the accessories and instructions you can expect (articles 6 and 7).

3. The window up close

The glass has no scratches, chips or stains.
Look from the side, against the light, inside and outside.
Profiles, handles and finish have no scratches or dents, and no foam or silicone left on them.
The colour and finish are those of the quote.

4. Opens, closes and locks

Each sash opens and closes several times without effort, without scraping, and closes with an even pressure.
This is the final adjustment: it is part of the job.
On tilt-and-turn windows, you tested both positions (open sideways and tilted) and the handle does not stick.
If it sticks, close with your hand on the handle, slowly: do not force it.
Shutters, insect screens and locks work on every window.

5. The installation around the frame

No gaps can be seen around the frame, inside or outside.
The outside finish is sealed where the rain hits.
The frame is level and plumb: the sash does not scrape or sit crooked.
The sill lets water run outwards, not into the wall.
The shutter box is covered and sealed, with no gaps in the lid.
The shutter box is a thermal bridge and lets in air and noise.
The old windows and the rubble were removed, if that was in the price.

6. Simple tests

Hand test: with the window closed, on a windy day, you ran your hand around it and felt no air.
These tests are practical, not standardised tests: a bad result is a sign to call the installer, not proof.
Light test: at night, with the light on inside, no threads of light show at the corners seen from outside.
Paper test: when you close the window on a strip of paper held against the seal, the paper does not slide out without resistance.
After the first heavy rain, there are no water stains on the sill or in the corners.
This point can only be checked later: tick it when it rains.

7. Before you sign or pay the rest

You wrote down and photographed everything that is wrong, and asked in writing for a date to fix it.
An email has a date and is on record.
You kept the date the installation finished (invoice, delivery note or message from the company).
The 3-year legal guarantee counts from there.
You photographed each finished window, inside and outside.
You only sign a handover note or an «all in order» after checking this list.
Before withholding any money because of a defect, ask DECO or a lawyer.
You set a calendar reminder to test every window again during the first 30 days.
If a defect appears in that time, you can ask straight away for replacement or cancellation (article 16).

Found a problem?

Photograph and note the problem, with the date, before the crew leaves.
Write to the company the same day (email) and ask for a date to fix it.
Use the letter generator for the formal notice, with the legal articles.
If it still goes nowhere, the guide explains the complaints book, mediation and arbitration.

Where this list comes from

Points 5 and 6 follow our guide to installing PVC windows; the labels come from the CLASSE+ guide and Regulation (EU) 305/2011 (CE marking); the legal deadlines are from Decree-Law 84/2021 (articles 6, 7, 11, 12 and 16). The simple tests in point 6 are common practice, not standardised tests. It does not replace a technician's inspection, nor legal advice.

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