Choosing windows is almost always choosing between two things. PVC or aluminium? Double or triple glazing? Every salesperson defends their own answer, and it is easy to get confused. Here we explain each choice in plain words, with what changes in cold, noise, upkeep and price.
There is no option that is best for everyone. It depends on the home, where you live and what you want from the window. So we show both sides and say when each one makes sense.
The two questions that come up most
PVC or aluminium? This is the choice of frame material, the border of the window. PVC insulates well by nature. Aluminium is slimmer and handles large openings, but it only insulates well if it has a thermal break (a plastic piece in the middle of the profile). Near the sea, the finish matters a lot. See PVC vs aluminium.
Double or triple glazing? This is the choice of glass. Triple glazing insulates more, but it is heavier, lets a little less light through and usually costs more. In many homes, good double glazing is enough. See Double or triple glazing.
A window is a set
One idea repeats in every comparison: a window is a set. The profile, the glass, the seals, the hardware and the installation all count.
Example: two homes with the same window. In one, the sealing around the wall was done well. In the other, gaps were left. The first feels warmer, even though the window is identical. A good choice badly installed loses its advantage.
So when you compare quotes, compare like with like: the same type of glass, the same opening, the same finish and the same installation.
How to compare well, step by step
- Write down what you want to solve. Cold, noise, damp, looks, price. Each problem calls for different things.
- Ask for comparable quotes. Same size, same glass, same opening. Only the thing you want to compare changes.
- Ask for the data sheets. Without them, promises are worth little.
- Ask about the installation. Who does it, how it is sealed, what it includes and what warranty is given.
- Decide calmly. Do not sign on the day of the visit if you have doubts.
Common mistakes
- Comparing a quote with plain glass against one with better glass.
- Choosing only by looks, without asking about the thermal break or the glass.
- Paying for the most expensive glass and forgetting the installation.
- Agreeing a price without anyone seeing the place.
Simple terms
- Frame: the border of the window.
- Thermal break: a plastic piece that stops the cold in aluminium.
- Double / triple glazing: two or three panes, with a sealed space between them.
- Ug: a number for the heat passing through the glass. Lower is better.
What to do next
Pick the comparison you are looking for in the list below. If you already know what you want, you can use the calculator to get an idea of the cost, or see how to ask for proposals in How to ask for a quote. Also see Energy efficiency to understand how the choices add up.