Windows are not just the “light openings” of the house, they also fulfill a wide range of functions in terms of room climate, energy efficiency, noise, and burglary protection. If windows are outdated, dilapidated, or damaged, this is much more than a purely visual matter. After all, windows that are not working properly have an impact on the entire building. But, is it even possible to renovate old windows? Is it worth it? And when is a window replacement unavoidable? Although we have mentioned the answer to all these questions in this article.
With a useful life of 48 years, windows are among the most durable building elements. However, as is so often the case, theory and practice only agree to a limited extent. Because outdated windows consume unnecessary energy by today’s standards and are considered expensive and environmentally harmful in times of continuously rising energy prices. For example, around a third of the room heat is simply lost through non-insulated glazing.
When is a window in need of a renovation?
There are several reasons why a window may need renovation. Since windows are permanently exposed to wind, solar radiation, and mechanical stress, both the glazing and the frame profile can be damaged over time or show natural signs of wear. Signs of windows in need of renovation include:
- Drafts penetrate the window
- Condensation forms on the inside of the pane
- The window no longer closes properly
- The fitting is difficult to operate
- There is visible damage to the frame such as cracks or gaps
- There is a single glazing
If one or more points apply, the window’s function is restricted. The effects range from unpleasant coolness in the living space and drafts to massive heat losses and accumulating moisture, which can cause mold and, in the worst case, damage to the building fabric. In addition, there are restrictions on living comfort, high energy costs, and visual defects.
Drafts: what are the causes?
Often it is only brittle and leaky window seals that create drafts. If the window is otherwise intact, seals can be replaced with little effort. It becomes more difficult when the window sash is adjusted, fittings no longer function properly or cold air penetrates through the frame profile. Professional help is required here. If it is just a matter of adjustments or defective handles, remedial action can be found quickly. However, if the frame profile or the connection to the masonry is affected, usually only a window replacement will help.
When the window is in need of renovation
There are different ways to renovate old plastic or wooden windows, depending on the type of damage and the material of the window. Basically, only wooden windows can be subjected to a real renovation. Plastic windows are considered to be more robust and tend to discolour at most over the years, which is a visual but not a functional impairment. Discoloration can usually be easily removed with a special plastic cleaner. If a plastic window is badly damaged, only a replacement will help.
Old wooden windows, on the other hand, can be professionally refurbished, but mostly the effort is out of proportion to the benefit. Even with the help of a renovation, old windows will hardly come close to today’s heat, noise, and burglar protection standards that modern windows have from the outset. Smaller damage to the wooden frame can be repaired with putty and varnish, and a new coat of paint gives the window a fresh look. A thorough renovation by a professional is expensive and is usually only worthwhile for historic windows, for example.
Even if the windows and frames are intact, modernization may be necessary. This happens when the window has outdated glazing that allows a large amount of heat to escape. In principle, more energy is lost through glazing than through masonry or the frame profile, for example. Single glazing, as can still be found in many old buildings, is extremely uneconomical by today’s standards and significantly impairs living comfort. This becomes clear from the so-called U-value. This indicates how much heat escapes through a window. The lower the U-value, the more heat-insulating the component. Old wooden windows with single glazing have a U-value of up to 5.8 W (m2K). Even around 20 years of wooden windows with double glazing still have a U-value of 2.7 W (m2K). For comparison: Windows in new buildings have a U-value of no more than 1.3 W (m2K). That is why it is only worth renovating wooden windows if they have a U-value below 2.0 W (m2K). If it is higher, renovation is not advisable.
But how do you find out how old the windows are and which glazing was installed? Usually, there is a sticker on the window itself, on which data such as year of construction and information on the glazing are recorded. Alternatively, the corresponding data is also noted in some windows on the aluminum rail in the space between the panes.
Replacing glazing: is it worth it?
If the frame profile and the connection to the masonry are tight and intact, it is possible to just replace the old glazing with, for example, heat-insulating or safety glass. Replacing the glazing is cheaper than a new window, but not always smoothly. Whether or not it makes sense to replace the glazing depends on various factors. Because if the frame profile is getting on in years, it is only a matter of time before the first signs of wear appear, so that a window replacement will eventually become necessary.
In addition, windows as structural elements are finely coordinated constructions. It is therefore questionable whether an older frame profile with modern glazing can achieve the same good thermal insulation properties as a new window. Modern glazing is also thicker and several panes are used, usually two or three. An outdated frame, which previously contained single glazing, often does not offer the structural properties and the space for modern glazing. Anyone who is thinking of replacing the glazing should therefore have the existing windows assessed by an expert and carefully weigh up the options on the basis of well-founded advice.
When should a window be replaced?
Today, experts advise replacing windows that are 20 years old or older. The reason: The requirements for thermal insulation, burglar resistance, and soundproofing have increased so much in recent years that replacing them is worthwhile in several ways. Thanks to the energy savings that result from modern windows, plastic windows, for example, pay for themselves after eight years. Added to this is the improvement of the indoor climate and living comfort as well as a fundamental increase in the value of the property through the renovation measure. In addition, windows should be replaced if they are no longer functional, have major or irreparable damage, outdated glazing is installed or the frame profiles no longer meet today’s standards.
Replace old windows
If renewing the seals and fittings or replacing the window glass does not bring any economic benefit, the only thing that helps, in this case, is to replace the window. When buying new windows, care should be taken to ensure that the window frame is weatherproof and has good insulation properties. The right choice of glazing also plays an important role. Such a project should be carefully considered and requires sufficient information, good planning, and the necessary manual skills.
The HEIM & HAUS experts are at your side with personal advice, tailor-made production, and professional installation for a safe replacement of windows.
Good reasons for new windows
In the vast majority of cases, replacing old windows is worthwhile. With the help of new windows, considerable energy savings are possible, the existing heating is kept better in the room and unpleasant coolness or drafts are a thing of the past. But not only the cold is better kept out by thermally insulated windows, summer heat also penetrates the interior more poorly through the insulation, so that it stays cool there longer.
- Improved thermal insulation
- Energy saving thanks to increased energy efficiency
- Summer heat protection
Since windows contribute significantly to the energy efficiency of a house, window replacement is generously funded. The state-owned KfW offers investment grants and low-interest loans for modern heat-insulating windows, and there are also various regional or municipal subsidy programs so that the costs for new windows can be amortized even more quickly.
Don’t forget: roller shutters and roller shutter boxes
If you opt for new windows, you shouldn’t forget the roller shutters. Because even outdated roller shutters are considered to be a major energetic weak point in the building, through which a lot of thermal heat escapes to the outside without being used. Basically, a roller shutter forms an additional insulation layer in front of the window. In the case of a window with thermal insulation glazing, the heat loss is reduced by 35 percent through a closed roller shutter, and by 80 percent in the case of insulating glazing.
The main problem with old roller shutters is that the roller shutter curtain does not roll up very tightly. This creates gaps in the roller shutter itself, and a lot of energy escapes through uninsulated roller shutter boxes. Modern roller shutters with special, thermally insulated bars roll up much closer. This results in additional space in the roller shutter box that can be used for insulation.
Even more advantageous than the costly insulation of an old roller shutter box is a modern, energy-efficient system that optimally combines roller shutters and roller shutter boxes, such as the “ Rollomatic SK 40 ” model. The roller shutter, which was specially designed for subsequent installation, impresses with its very good U-values and its well-thought-out overall construction ensures high energy savings. for further detail, do not hesitate to contact Litman Construction Company in Duluth, MN.