“It has a warranty” is one of the phrases heard most when buying windows. But for how long? Covering what? Who answers? If it is not written down, it is only a phrase. Here is what to ask for in writing and which papers to see.
Note: we are not lawyers. Laws change and depend on each case. We deliberately give no time limits or legal articles here. Where in doubt, check the official sources listed at the end.
Why a warranty matters on a window
A window is made to measure, fitted into the wall and used every day for many years. Problems can show up months or years later: a hinge that gives way, a seal that comes loose, water between the two panes, air passing around the frame.
Imagine that two years later a sash stops closing properly. If the warranty is written and you know who to call, it is sorted with a phone call. If all you heard was “it has a warranty” at the counter, you start an argument with no proof.
Which warranties exist
There are, in general, two kinds:
- The legal guarantee. Portuguese law protects people who buy as consumers. The time limit and the rules depend on what you bought and the terms of the sale. Ask the company and check on the Portal do Consumidor (the consumer portal).
- The company or manufacturer warranty. This is an extra the company offers. It is only worth what is on paper.
An extra warranty does not replace the legal one, and the other way round. But it helps to know which of the two is being talked about when someone says “it has a warranty”.
What should be written down
Ask that the quote or contract states:
- How long the warranty lasts.
- What it covers and what it does not. Frame, glass, hardware (hinges and handles) and installation can have different periods.
- Who gives it: the company, the manufacturer, or both.
- How to claim: who you call, by what means, and how fast they reply.
- What voids it. For example, whether it requires regular cleaning or maintenance, or whether adjusting the window yourself loses the warranty.
Example: the double glazing ends up with water between the two panes. If the glass warranty is in writing, you know who to call and what to ask for. If it is not, the conversation is much harder.
Which papers to ask for
| Paper | What it is for |
|---|---|
| CE marking and declaration of performance | Shows the product meets the rules to be sold in Europe and gives data on the window |
| Technical sheet for the frame and the glass | Confirms brand, model and make-up |
| CLASSE+ label (if there is one) | Speaks about the window’s energy efficiency |
| Invoice with your tax number | Without an invoice it is hard to use any warranty |
| Signed quote and contract | Prove what was agreed |
Windows sold in the European Union usually have CE marking and a declaration of performance. Ask to see them and keep a copy. For the CLASSE+ label, check the current rule with ADENE. See CLASSE+ label.
What a certificate does not say
A nice-looking paper does not mean the window was well installed. CE marking and technical sheets speak about the product. They do not speak about the job. An excellent window, badly fixed and badly sealed, lets in air and water, and no certificate changes that.
So it pays to look at the product warranty and the workmanship warranty. See what installation should include in PVC window installation.
Does the installation have a warranty too?
Ask. Many problems (air getting through, water coming in) come from the installation and not the window. Ask that the installation warranty, the responsibility of whoever did it, is in the quote. If the company subcontracts the fitting, ask who answers for it.
The most common mistakes
- Accepting “it has a warranty” with no time limit and no paper.
- Not asking for an invoice, to pay less or “without VAT”. Without an invoice, you lose your proof.
- Not keeping anything. After a year nobody remembers what was agreed.
- Waiting to complain. If you see a defect, say so at once, in writing.
- Thinking the certificate covers the job. It does not.
Keep everything
After the job, keep it all in one place (a folder on your phone will do): quote, contract, invoice, warranty and technical sheets. Take photos of the finished work. If there is a problem, write (email) and keep the reply. An email has a date and is on record.
If a defect appears: step by step
- Photograph it and note the date. Show the defect and the whole window.
- Write to the company (email), with the photos, and say what you want solved.
- Keep the reply and the date it was sent.
- Allow a reasonable time for an answer. If there is none, write again.
- Ask for help from an official body if the company does not solve it (see below).
Whoever has the papers and photos to hand sorts out these situations much faster.
Mini-glossary
- Legal guarantee: the protection the law gives people who buy as consumers.
- Commercial warranty: the extra offer from the company or manufacturer.
- CE marking: a sign that the product meets European rules for sale.
- Declaration of performance: a document with window data, such as air and water tightness.
- Technical sheet: a page with the features of the frame or glass.
- ADENE: the Portuguese energy agency, linked to the CLASSE+ label and the energy certificate.
Where to check
- Portal do Consumidor (Direção-Geral do Consumidor): consumer rights and warranty periods.
- ADENE: for the CLASSE+ label and the energy certificate.
- Complaints book (livro de reclamações), if the company does not sort it out.
For a more expensive or complicated contract, ask a consumer association or a lawyer for help.
What to do next
- Use the Checklist before hiring with the warranty in hand.
- Ask the Questions for the installer.
- Want to compare figures? Read How much do PVC windows cost or use the calculator.