Replacing Windows: 7 Signs It’s Time for New Windows

Windows last a long time – but not forever. After 25 to 30 years, many windows no longer reflect the state of the art: they insulate less well, no longer close properly and let heat escape. How can you tell that a replacement is worthwhile? These seven signs are clear indicators.

1. There is a draught at the window

If you feel a draught with the window closed, the seals are worn or the sash no longer closes properly. A simple test: trap a sheet of paper between the sash and the frame. If you can easily pull it out with the window closed, the window no longer seals at that point.

2. The panes mist up on the inside

Condensation on the inside of the glass – especially along the bottom edge – shows that the glass surface is too cold. This is typical of old double glazing with aluminium spacers. If the pane mists up between the glass layers, the edge seal has failed. Read more in our article on window condensation.

3. Heating costs are rising

Older insulated glass windows often only achieve a Uw value of around 2.7 W/(m²K) or worse. Modern windows with triple glazing lose only a fraction of that heat. Our guide to the U-value explains what the figures mean.

4. The sashes stick or drop

Stiff handles, sashes that rub, or windows that barely close indicate warped frames or worn hardware. Adjustment sometimes helps – but spare parts are often no longer available for very old windows.

5. It is noisy indoors

If you can clearly hear traffic and conversations outside, the window is not providing enough sound insulation. New windows with acoustic glass make a noticeable difference – see our article on soundproof windows.

6. Frames and joints are damaged

Rotting wood, peeling paint, yellowed or cracked PVC profiles and leaking joints are more than a cosmetic problem. Moisture can penetrate through cracks and damage the building fabric.

7. The windows are easy to lever open

Older windows often only have simple roller cams that can easily be levered open with a screwdriver. Modern hardware with mushroom cams and security keeps offers much better protection. Read more about RC2 burglar resistance.

Grants and minimum requirements

Many countries support the replacement of old windows with energy-efficient ones – through grants, tax relief or reduced VAT. The conditions vary widely: the new windows often have to reach a certain U-value, the work may have to be carried out by an approved installer, and the application usually has to be submitted before you sign the contract. In Germany, for example, the BAFA subsidises 15 per cent of the eligible costs for windows with a Uw value of no more than 0.95 W/(m²K). Many countries also set a maximum U-value for replacement windows in their building regulations.

Check which national or regional programmes apply to your home before you order. We will gladly provide the technical data (Uw value, glazing, spacer) needed for your application.