Refurbish or replace old windows?

Old windows have several disadvantages compared to their modern counterparts. In particular, they are not able to match newer windows in the areas of thermal insulation and soundproofing. This means that old windows are faced with considerably higher energy costs. To improve these features of the windows, it is worth considering a refurbishment or a complete replacement. This improves the thermal and sound insulation, while new models also provide much better burglary protection. Several options are available: The windows are either completely replaced or they are refurbished, in which case on the seals and front panes and/or the glazing are replaced. Besides the difference in cost, the age of the window as well as the type and condition of the building must also be taken into consideration. One of the three methods is then selected depending on the situation.

Window refurbishment is quite economical compared to a complete replacement or the replacement of the glazing. It can only be considered if the building structure and window frames are in good condition. Different sealing materials can be installed depending on the features of the window that are to be improved. Different materials and processes are used for better thermal insulation, optimised soundproofing or to protect against humidity. For example, in old wooden windows without a seal, this can be integrated into the frame as a band. Besides the different sealing materials, the installation of additional or front panes is also possible and improves the window’s thermal insulation. The U value of old single glazing can be improved by up to 40 per cent. The U value is a measure of a window’s heat permeability. This method also improves the soundproofing and burglary protection. Another option is the installation of window foils, which ensure optimal sound and thermal insulation.

If the window frame is still in good condition, it may be possible to replace the glazing to improve the window’s thermal insulation. This is particularly sensible if the frame needs to be preserved for optical reasons or due to the building’s heritage protection. Besides modern multiple glazing, coated panes can also be installed. But their U value is generally poorer than for normal panes. In addition, when refurbishing a window with an open fireplace, it is important to consult a chimney sweep before starting the refurbishment. This is because changing the window’s insulation also changes the external air supply, which can have a negative impact on the fire.