PVC or aluminium: which suits me?
There is no winner. There is a different answer depending on where your home is, which way the window faces, and what bothers you most. Since I am not an official dealer for any brand, I have no reason to push you either way.
PVC
It insulates best and cuts the bill most. Inside, the profile carries air chambers and a steel reinforcement through the centre that gives it rigidity.
In exchange, the frame is thicker than aluminium. On a small opening you notice it: slightly less glass and slightly less light. On a big opening it barely matters.
Thermally broken aluminium
The profile is slimmer, so you gain glass and you gain view. It carries an insulating strip through the middle of the profile, the thermal break, which stops heat crossing the metal from outside to in.
It stands up better to hard sun and sea air, which is why on the sea front it is usually the better choice even though it insulates slightly less well.
Watch for one thing: aluminium without a thermal break is probably what you already have, and it is the worst possible window in this climate. The metal conducts heat straight indoors. If a quote just says “aluminium”, ask whether it has a thermal break.
Composite
Wood or PVC inside, aluminium outside. It insulates like PVC while the sun and the salt cannot touch the outer face. Best of both, and the most expensive.
How I decide at your house
- Sea front or a lot of wind, like Calpe, Santa Pola or the Benidorm front: I usually lean to thermally broken aluminium.
- Inland with hard summers, like Elche or Orihuela city: PVC nearly always wins, because the cooling saving is what weighs most.
- A flat on a busy avenue: here the glazing and the seal matter more than the frame material. This is where most people spend on the wrong part.
- A small opening where you want light: aluminium, for the slim frame.
- A house shut up half the year, typical in Dénia or on the Orihuela coast: watch for condensation, and there the glazing matters as much as the frame.
What almost nobody tells you
The PVC versus aluminium argument takes all the attention, and in many homes it is not what changes the result most. What changes the result most is the glazing and the seal between the frame and the wall.
An excellent window badly sealed performs worse than an ordinary one fitted properly. That is why the measuring visit is not a sales formality. It is where it is actually decided whether you will feel the difference.