In an old house or a flat with poorly insulated windows, a lot of heat escapes. Especially in winter, when you heat your home expensively. Double-glazed windows have a U-value of around 3 watts per square metre Kelvin, triple-glazed windows 0.5 or 0.6 watts. Triple-glazed windows allow much less heat to pass through the glass and insulate just as well as a solidly insulated wall. Switching from double to triple glazed windows improves the thermal insulation value by around 80%. This is why new windows are one of the simplest and most effective measures to sustainably optimise the energy efficiency of old houses or flats. New windows (frames and panes) have an energy saving potential of 5 to 10 per cent.
Wooden windows have a lifespan from 20 to 40 years and need to be maintained every 10 years, while plastic and metal windows last longer but need to be maintained more often. If windows have never been renovated, they will become as old as the house or flat. If they have been renovated, the year of renovation should be indicated among other things with a sticker or metal plate on the window frame. Without evidence of window renovation, the age can be estimated based on the year the house was built:
If your windows still look good but you are not sure how old they are, there are two clues to see if the windows are still sealed well enough or not:
A window renovation has an energy saving potential of 5 to 10 per cent. However, you can only exploit the full savings potential with a comprehensive energy renovation. With a new heating system, better external insulation and modern insulating windows with an energy efficiency class A, you save around 60 per cent of electricity. This saving is well worth it sooner rather than later, because you use less electricity for heating and surcharges or long, cold winters are less of a burden on your budget. Also, after a window renovation, humidity in the house increases without a complete renovation. Afterwards, you will have to ventilate the rooms more often than before to avoid mould. After a complete renovation, the risk of mould is almost zero because the individual energy measures are coordinated with each other.
The choice of frames depends on your budget, your taste and your home. These are the most important characteristics of different frames:
Skylights are even more exposed to wind and weather than other windows. That's why you should regularly check them for cracks and frame damage, rotten wooden frames, cracks between frame components, tarnished glass and porous or missing seals. Roof windows last more/less than 25 years and should be revised every 6-8 years as they are subject to a lot of wear and tear.
A window renovation has numerous advantages. These are just the 7 most important ones: New windows ...
Simple wooden windows are the cheapest, wooden or plastic-aluminium windows are the most expensive. Triple-glazed windows cost more than double-glazed windows. And double-hung windows are more expensive than single-hung windows. Expect to pay 400 to 600 Swiss francs per square metre of surface area for a modern triple-glazed window. Extras such as tilt and turn hinges, improved sound insulation or safety glass cost more. The work of a window fitter costs between 100 and 150 francs per hour. Also take into account the time for the journey to and from the site and the disposal of the old windows.
No, window replacement alone is not subsidised. Window renovation is relatively simple and inexpensive. That is why many homeowners want to replace old windows first. However, if only the windows are renovated in an uninsulated house, moisture rises and accumulates as dampness in the brickwork instead of condensation on the window. This leads to mould, which attacks the structure of the building. Therefore, subsidy programmes only finance new windows as part of a complete renovation.
The Buildings Programme provides subsidies for the renovation of windows as part of general renovations (measures M-10 to M-15) or for new buildings (M-16 and M-17). It is best to proceed step by step if you want to apply for financial support: