Do I have to replace all my windows at the same time?

No, but grouping your windows in one order makes the installation simpler, gives the façade a uniform look and makes grant applications easier.

What is the best time of year to replace windows?

Any time of year. Each opening is only open for a very short time, because the new window goes in as soon as the old one comes out.

When to replace windows: 7 signs to look for

When should you replace your windows? 7 clear signs

It is time to replace your windows when you feel draughts, when condensation appears between the panes, when you still have single glazing or when the frames no longer close properly. Outside noise, a cold feeling near the glass and heating bills that keep rising are clear signs too.

By Marcio Barros · Updated 31 October 2026 · 5 min read

1. Draughts around the windows

A candle flame that flickers near a closed frame, a cold feeling on your hand: the seals are worn or the frame has warped. Adjusting the window can help for a while, but an old window will not become airtight again.

2. Condensation between the panes

If condensation appears between the two panes of double glazing, the seal of the glazing unit has failed. The insulating gas has escaped and the glass barely insulates any more. See our guide to condensation on windows.

3. Single glazing or old double glazing

Single glazing loses a lot of heat. Double glazing that is more than twenty years old also insulates far less than modern triple glazing.

4. Frames that are hard to open or close

Swollen timber, worn hardware, a handle you have to force: beyond the annoyance, a window that does not close properly lets in air and water.

5. Street noise

If traffic, trains or aircraft are always in the background, new windows with the right glazing make a real difference day to day. See our guide to soundproof windows.

6. A cold feeling near the glass

Even when the heating is on, a room stays uncomfortable next to cold windows. Triple glazing almost removes that feeling.

7. Heating bills that keep rising

In a poorly insulated house, windows are among the main sources of heat loss. Replacing them cuts those losses, and Klimabonus, the Luxembourg state grant, can help pay for the project if your home meets the conditions.

What next?

A free measurement visit lets us check the condition of your windows and walls, and you receive a fixed-price quote. See also our window replacement page.

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