Windows: Experiences, background knowledge, tips
Windows are the kind of utensils we hardly think about, if at all - as long as our windows to the world are intact and function as they should. There are many different types and models, which we will briefly discuss here - as well as some tips on how to deal with the glass holes in the wall. In the following you will find a personal experience report. Our author has dealt with the subject of windows in detail and professionally for several years, both in theory and in practice. So there is first-hand information - for more insight into the topic of windows.
Windows - definition and types
Single glazed windows
This type is an outdated form of window in which a pane of glass is set into a frame. Usually, these frames were made of wood or metal and the panes cut to size were fixed in the frame using "window putty". This kneadable compound dries hard and withstands a wide variety of stresses. In the case of wooden frames, it was also common to fix panes with so-called pin nails to increase stability in the frame.
Double-glazed windows
Double-glazed windows were the forerunners of the thermopane glazing that is common today. With double glazing, window makers simply put two panes in one frame to reduce the temperature condensation effect. The layer of air between the panes prevents room humidity from settling directly on the panes when the room and outside temperatures differ greatly. In some countries, such windows are still permitted and newly available today.
Thermopane windows
Thermopane glazing is the modern and now common version of double glazing. To increase the insulating effect, manufacturers provide thermopane panes with a vacuum instead of a layer of air between the two panes. This vacuum not only prevents the inner pane from fogging up, but also insulates the entire window.
Leaded glass windows
Leaded glass windows are often elaborately produced mosaic windows in which small glass segments are assembled over cast lead bridges and held in the frame. Over such mosaics, craftsmen in the Middle Ages produced impressive motif windows that we all know from churches, cathedrals or other sacred buildings. Since such windows can only be made by craftsmen, there are few new and modern leaded glass windows. Now and then, the sponsors of cultural buildings have a budget to have such windows made for them.
Windows at a glance
Windows have only been closed with glass in Europe since around 1000 AD. Before this time, it was occasionally customary to close windows with wooden flaps (shutters). Glass windows were first found mainly in sacred buildings such as chapels and churches, as well as the estates of wealthy merchants or their guilds. Wooden shutters are still used today. However, they do not replace the glass window, but can be closed in front of the window, usually with two leaves, to reduce the incidence of light or to protect the window. In France and Bavaria in particular, such shutters are still part of the townscape. In Bavaria, such shutters are often lovingly decorated and painted.
Windows through the ages
The most visible difference between historical and modern windows lies in the size of the glass surfaces. While today we are able to produce very large glass surfaces with rollers, our ancestors helped themselves by assembling smaller glass elements. This was done by dividing the surfaces with wooden frames or metal grids, into which smaller panes were then inserted, or with so-called lead glazing, in which slugs or glass mosaic elements were assembled into often elaborate mosaics. Historic bull's-eye windows are windows that are composed of many round panes. The term "Butze" refers to the bottom of a bottle. It was precisely from this that such glazing could be made. Today, we only find such bull's-eye windows with the original round glazing in a few historical buildings. However, the term "Butzenfenster" has passed through the centuries and many older farmhouses, e.g. in North Friesland, have such windows. These windows, which were made later, now have square "slugs". The only thing that has remained the same is a greater thickness of these panes compared to "normal" panes and the possibility of cementing such panes into wooden grids without using elaborate lead glazing. We know leaded mosaic windows in often impressive motifs from larger churches or cathedrals.
Traditional windows
The difference to modern windows are the smaller glass surfaces. In historical leaded glass windows, smaller glass segments were often joined together with cast lead to form larger panes. In churches not infrequently to beautiful mosaic motifs and in simple town houses to so-called bull's eye windows. Nowadays, such elaborate lead glazing is no longer produced industrially and we only encounter such glazing next to historical buildings in house doors or interior partition glazing in the style of Art Nouveau. Frisian farmhouses in the North Sea coastal area often still have traditional bull's-eye windows. Since the old days, these rural bull's-eye windows have changed somewhat. After the original round glass elements, the bull's-eyes are now square in many places. However, the glass is still much thicker than that of simple glass panes. For many Frisians, such bull's-eye windows are part of their traditional style. In this respect, tradition-conscious people will hardly want to move away from these windows in the future.
Single-glazed windows
The next stage in window history was larger single-glazed windows. We still find such windows today in unheated farm buildings such as stables or workshop sheds.
Old windows in a modern world
The effects of such single glazing are familiar to museums, for example, which are often not authorised to replace historic windows in their historic buildings due to requirements imposed by the preservation authorities. The biggest problem for the preservationists is then moisture in the interiors in the immediate vicinity of the windows. In Schleswig's Grey Monastery, such concerns led to the closure of a frequently used function room a few years ago, as restorers were concerned that the moisture could permanently damage a wall painting.
We all know the problem in the winter months, with our single-glazed motor vehicles. The difference in temperature causes the windows to mist up, and moisture from the air collects on the panes. It beads up or even freezes. This is exactly what happens with single-glazed buildings. Moisture damage would be the direct result.
Thanks to our thermopane windows, we no longer have this problem in the flats. Moisture would then be an unmistakable indication of a defective window. Defects occur as soon as the vacuum between the two panes draws air and thus also allows moisture between the panes. As soon as thermopane panes mist up from the inside, they are broken and must be replaced and repaired.
Now only thermopane panes are used
Modern thermopane windows are standardised and do not differ in manufacture and function. Visible differences exist only in size and framing. Since frames are manufactured to the window dimensions, all window surfaces can be glazed without any problems. In the case of unfavourable dimensions that could call into question the stability of a window surface, glaziers and frame builders work with top or bottom lights. These are areas separated by frame beams that divide the total area. This makes the complete glass front more stable.
Nowadays, window frames are mainly made of plastic or aluminium. Some companies still use woods such as mahogany. Other woods have now proven to be less durable. In the years 2010 to 2012, countless windows were replaced after the wooden frames, mostly from the construction years of the 1960s and 1970s, showed too many defects. Such defects could be avoided as soon as we take care of wooden window frames in the same way as wooden balcony parapets exposed to the weather, for example. But which tenant would be prepared to paint his windows with wood preservative once a year? The old wooden frames have been replaced with the now common plastic frames. Plastic frames can be custom-made to fit the installation size. The glazing is then inserted into the frame on site by the craftsman and fixed with clamping rails. This means that all window sizes can be supplied individually. If the window area is too large, the craftsmen will plan vertical separations, for example, to reduce the leverage effect of an open window sash.
With modern thermopane panes, two panes of the same size with a thin space in between are put together in production so that this space has a low vacuum. This airless space reduces the thermal conductivity and the thermopane window thus additionally insulates a heated interior. In older buildings, there are sometimes still double-leaf windows that have double glazing but do without the vacuum. Such windows are even available from modern production in other European countries such as Denmark, France, Poland and the Czech Republic. Here in Germany, the new installation of such low-insulation windows is prohibited or not common by current building regulations.
Where can we find single glazing?
Single-glazed windows are very simple panes of glass. To give a larger window more stability, single-glazed windows were often divided into smaller segments, into which relatively small panes were then inserted.
In the past as well as today, the panes are held in the frame with window putty. Window putty is a kneadable mass that dries and hardens over time. Nowadays, single glazing is almost only found in the front door glazing of older apartment buildings or unheated farm buildings in agriculture. Such single glazing is no longer suitable or permitted for heated living spaces. Firstly, the windows would constantly mist up and form puddles on the window sills, and secondly, too much heat would be lost with such windows. For unheated farm buildings, stables, workshop sheds or similar, this far more cost-effective option is still used.
One advantage of such glazing is that it is inexpensive to repair. If a pane is broken, all that is needed is a suitable pane from the local glazier and someone who knows how to handle window putty and pin nails. Thermal glazing is not so easy to replace by yourself and usually requires a craftsman.
Historic leaded glass windows
The situation is quite different with historic leaded glass windows from the Wilhelminian period or even the Middle Ages. Since such windows are often subject to monument protection, a craftsman from the local trade area and under no circumstances a do-it-yourselfer will suffice for a repair. For the repair of such historical treasures, restorers are employed who are so familiar with materials and historical working methods that historical windows do not lose their historical character even after repair. The costs for such restorations are incomparably higher than a regular craftsman would charge. In the case of public historic sites, however, there may be subsidies available for this purpose, which can be inquired about and applied for through the State Office for the Preservation of Monuments. The essential criterion for the possible approval of such subsidies, as well as specific requirements of the responsible monument authority, will be less the condition of the object than its historical value. Depending on the location, the requirements can vary considerably. In the historic Hanseatic city of Lübeck, the Local Office for the Preservation of Historical Monuments has completely separated itself from the state office and requires house owners in Lübeck's inner city to absolutely preserve historical aspects. When repairs are carried out by restorers, it should be noted that they do not simply remake the old window, but proceed according to restoration-ethical procedures that, on the one hand, guarantee the functionality and safety of the object, but at the same time leave the historical essence as untouched as possible. Depending on the age and material of the window to be restored, such repairs can take months and are then also associated with considerable costs.
With bull's-eye windows, the situation is often not quite as serious as with leaded glass windows. Admittedly, bull's-eye windows are often very old, but in most cases they are not the jewel in the crown of a historic façade. Not infrequently, bull's-eye windows are found in old Frisian farmhouses and have also often given way to modern thermopane panes or modern, newly manufactured bull's-eye windows. Modern bull's-eye windows usually have square glass elements and not, as in earlier times, round elements. The word "butze" goes back to a bottle bottom and indeed these thick and sturdy glass segments were used to make panes. Even in modern slugs, the glass is three to four times thicker than a conventional glass pane. However, modern slugs, which are often curved, are no longer made from old wine or beer bottles.
For owners who do not want to forego the antique look of their old farmhouse, there are window manufacturers who supply modern windows but model them after the antique slug windows. Such windows cost more than the inexpensive DIY store variety, but they add to the charm that is often very traditional in rural areas.
Double glazing (thermopane windows)
Thermopane windows are double-glazed windows in which a small vacuum is created in the space between the panes during manufacture. The panes are then joined together by a silicone-like bonding and delivered by the glazier already as a "double pane". The window frame is then adapted to the dimensions of this pane and can basically be individually manufactured by frame workshops for any pane size. The double pane is then inserted into the frame, the contact surfaces of which are provided with rubber seals and fixed in the frame by means of clamping rails. These clamping rails are attached to the inside of the pane, as otherwise a break-in would require little effort. If these clamping rails are removed, the window practically falls loosely out of the frame.
Double-glazed windows have weight. In the case of larger panes, it is advisable to refrain from opening a sash completely immediately after installation, as the weight and leverage may be sufficient to tear the entire frame out of the still fresh masonry. Craftsmen will point this out after installation and will emphasise how long it will take until a window can be opened safely and without hesitation. This waiting time is estimated at 24 hours.
The purpose of double glazing with a vacuum interspace is to prevent moisture in the interior due to fogging and to reduce thermal conductivity and thus the loss of heat, which would be much more serious with a single window pane.
Due to their construction and framing, thermopane windows are also much more robust than single glazing. It takes far more force to break such a pane with, for example, a football.
By far the majority of windows around us are thermopane glazing and certainly you will get such windows broken. A very important indication of broken thermopane glazing is moisture between the panes. Misting up of the pane is the wake-up call to consult a professional and then decide whether the window needs to be replaced.
Window selection for new buildings
Those who decide to have their own house or building built will usually not have the freedom of an Antoni Gaudi and revolutionise architecture. Likewise, hardly any builder will stroll through the DIY store and choose every window or roof tile himself. An architect's office in Germany is absolutely necessary for the statics of the building alone. In his designs, the architect will certainly be guided by the wishes of the building owner, but he will also have specific requirements of the municipality and building regulations in mind, which can vary greatly depending on the location of the property. Particularly in the case of development plans for housing estates, the architect's office will be required to fit the new building into the look of the area. The situation becomes more complicated in historic cities such as Lübeck, where the preservation of historical monuments attaches great importance to ensuring that even new buildings do not destroy the historic charm of the streetscape. All such considerations will therefore also contribute to which windows the architect plans for a new building. If you take a walk through a new housing estate, you will easily notice that almost all houses have very similar windows.
Local building regulations are usually decided at the municipal level. In rural communities, these are even more amenable to suggestions than the town planning departments of larger cities. However, we will probably not get a "Villa Kunterbunt" approved anywhere in settlement development plans. Unless, of course, we find a more secluded development site where the new building does not spoil the "look" of a street or settlement.
However, the builder will have a say in the size of the window fronts, which the architect will then have to reconcile with the statics of the building.
There are almost no limits to the technical possibilities. In the north-east of the Danish city of Randers there is a housing estate where various architectural firms were allowed to show their visions of the future in a competition. From opulent glass cubes to spaceship-like bungalows, there are houses there that we can hardly imagine in Germany in any other place. Such houses prove the possibilities of architecture. At the same time, they raise the hope that new buildings in the future will not necessarily stop at the traditional terraced house with a gable roof.
In addition to deviating window fronts, the architect will include double glazing with thermopane panes in new buildings. Regardless of whether a single-family or multi-family house is being built. Thermopane glazing is standard in order to save heating costs and provide ideal insulation.
Thermopane windows are available in various standard sizes, which are known to every architect and which he will take into account in his planning. In principle, however, we can have thermopane windows made in almost any size. A glazier supplies the double glazing, a frame builder will make the appropriate frame. It will then depend on the developer's budget whether the client insists on special sizes, or on more favourable standard dimensions.
The same question will arise in the choice of frames. Plastic frames are usually chosen for apartment buildings. Many public buildings such as hospitals, authorities or schools have aluminium frames. Only in private single-family houses do we still encounter more expensive mahogany frames. Some companies have specialised in importing such frames cheaply, especially from Poland and Finland, so that private builders do not have to do without decorative wooden frames. Since such wooden frames require somewhat more conscientious care, architects will continue to forego this option for public authorities and apartment buildings. The noble wooden frames are not better in this respect. Plastic and aluminium frames also serve their purpose. In this respect, wooden frames are probably currently chosen mainly for purely aesthetic reasons.
Important criteria for the choice of windows will be decided by architectural offices according to the following aspects:
Building types
It makes a difference whether the developer has to equip a single-family house with windows, an apartment building, a public authority or a hospital. The architect will then be guided not only by functionality, but also by affordability.
Another criterion would be compliance with urbanisation and development plans and the community-specific design of settlements and neighbourhoods. The architect's office might not seek such conditions from the developer, but from the city or municipal authorities.
The preservation of historical monuments would come into play if streets or districts were not to be pulled out of an overall historical concept. As a rule, the state offices for the preservation of historical monuments are the first point of contact here. In exceptional cases, individual rules apply, such as the historic Hanseatic city of Lübeck, which was able to detach its monument preservation almost completely from the responsible state office in order to better defend municipal interests. Such exceptions are rare and not always popular. New buildings and conversions in Lübeck's old town are associated with far more hurdles than in any other place in the state of Schleswig-Holstein.
Less effort and cost will be involved in the selection of factory or plant buildings. Particularly in the case of partially unheated building complexes, costly glazing can be dispensed with. In factory buildings, architects sometimes do without windows completely and choose translucent wall elements. Such elements are also sometimes found in stairwells of schools, apartment buildings or public authorities.
Such elements are not windows and therefore do not have to fulfil the same stability requirements. They are only intended to provide daylight illumination for corresponding parts of the building. Such light elements cannot be opened or tilted. In a few designs, however, there are ventilation openings that can be tilted by means of cable or rod pulls.
Similarly, single glazing is quite common in factory buildings. Here, large window areas are dispensed with and such windows usually consist of smaller glass elements inserted into grilled frames.
Development plan
In the case of housing estates, special streets with homogeneous development, architectural firms will adhere to a holistic appearance or orient themselves accordingly.
The same applies to historic neighbourhoods, although here the costs often have to be calculated higher, as new windows based on historic windows often have to be individually manufactured and are not chosen from the standard catalogue of suppliers.
Windows in rented flats
Many people in Germany live in rented flats and therefore do not have the embarrassment of having to choose their own windows. Windows, like radiators or other functional fixtures and fittings, are part of the basic equipment of a flat.
This also applies to a case of damage, as long as it was not caused negligently or intentionally by the tenant. The replacement of old or defective windows is not considered cosmetic renovation and does not burden the tenant financially. Rent increases after the installation of new windows are completely unusual, although we can no longer rule out such actions by some housing associations. An objection is definitely worthwhile in such a case, and the Mieterschutzbund will certainly have current case studies on this.
New windows only in case of renovation or defect
The likelihood that we as tenants will end up with new windows is comparatively low, as the lifespan of modern windows usually outlasts the duration of regular tenancies. Owners and property managers often associate the replacement of windows with major renovation campaigns. In this context, it is advisable to ask the landlord whether such renovations affect the service charges.
The tenant always has a claim to repair in the case of defective windows. Not only if the glazing is damaged, but also if the closing mechanism of the windows is defective and windows cannot be opened or closed normally. Such repairs are not slapped on the tenant, but are covered entirely by the landlord.
How we recognise defective windows.
An unmistakable sign is moisture. Misted-up panes, condensation or even puddles on the windowsill are signs of a defective window. If fogging occurs between the two panes of thermopane windows, this is a sign that the window is drawing air. The moisture contained in the air then settles between the panes when the temperature drops. The window is broken or no longer fulfils its insulating purpose. Defects in the closing mechanism of the windows are also obvious. Windows are stuck and can no longer be opened or closed as usual.
All such defects should be reported to the landlord instead of hiring a craftsman on your own. We do this either with the owner or landlord himself, or through the property management company. Some property management companies have appointed caretakers whose telephone numbers can be found in many hallways or stairwells of apartment buildings. The caretaker will then forward the damage to the property management and then decide whether the repair will be carried out by the caretaker or an external craftsman. Damage to the locking mechanism will in most cases be repaired by skilled caretakers. Even the replacement of entire hardware rails and locking mechanisms is relatively uncomplicated for standard sizes.
In the case of defective panes, a glazier is usually called in to supply appropriate panes. The replacement of entire windows with frames is usually carried out by carpentry firms and is a greater, though not unmanageable, expense. Provided that the damage is demonstrably not caused by the tenant but is due to wear and tear or weakness of the material, the tenant will not have to pay a cent of his own for such repairs.
Appointments.
We cannot assume that tenants will squat in their flat day and night waiting for workmen to drop by. If an appointment is required, the tenant should seek contact with the landlord or caretaker to find out which tradesman is scheduled to carry out the upcoming repair. Owners and property managers often work with tradesmen they already know.
Do-it-yourself or self-repair should be completely avoided. Even if we think we have discovered a totally resourceful Youtube video. If this repair goes wrong, the landlord will almost certainly not cover the costs of the professional repair. Costs for craftsmen not infrequently amount to several hundred euros. The risk of increasing the damage is not small. A trained craftsman is the right choice in most cases.
If the complete window (with frame) is to be replaced, there are a few preparations to be made in addition to the appointment. First of all, you should make sure that the craftsmen, including their toolbox, have free access to the window. Such a replacement will not be completely dust-free. You should therefore take the precaution of moving sensitive equipment or objects out of the line of fire.
Before the actual appointment, a craftsman will show up to inspect the location, measure the window and note in which direction the window sash opens. This visit should be used to ask if any furniture or appliances should be moved out of the way.
Problems can always arise when making appointments, as many trades sometimes experience seasonal bottlenecks with full appointment books. Waiting times of several months are not uncommon. Unless the glazing is broken and the window can no longer be closed. In this case, the landlord will also resort to emergency services and, if necessary, accept additional costs in order to prevent moisture damage, for example.
Repairs to the locking mechanism can usually be quickly remedied by adjusting screws or, if necessary, replacing a locking bar or fitting. Even with this work, a longer waiting time must be expected when making an appointment, unless there is an emergency in which, for example, a window can no longer be closed and would de facto remain open until the repair.
Procedure and duration of a window replacement.
The replacement of a complete window with frame is not a lengthy affair. Skilled craftsmen will be able to carry out the replacement in about an hour. The window sizes are also independent, as the work steps are completely the same for both large and small windows. Deviations can of course occur with particularly large window fronts.
In the first step, the craftsmen will flex along the "butt" of the frame on the inside in order to detach the frame from the masonry. Depending on the age of the frames, they are doweled to the masonry with masonry screws or metal straps. The flexing will not be dust-free. However, many craftsmen use machines that can be connected to a hoover to remove the coarsest dust directly. The old frame is then levered out of the masonry and, in most cases, cut in the process. Even craftsmen will seldom be able to remove an old frame "safely".
As soon as the old frame has been removed, the new frame is taped around the outside with a special sealing tape and placed in the window hole. After the frame is aligned using air cushions, the craftsman fixes the new frame with four masonry screws. These are longer 10mm screws with a coarser thread that can also be screwed into the hole without dowels. Once the window frame is aligned and fixed in the opening, the space between the frame and the masonry is foamed with rigid foam. In the meantime, the glass is inserted into the window sash and the opening handles are mounted. As long as the craftsman is on site, the sashes can be hung immediately. However, the window should not be opened until the foam has completely hardened. Finally, the foils are pulled off the frame and adhesive rails are applied on the inside and outside to ensure a clean finish. The next day at the latest, everything is completely cured and the window can be opened as usual.
Ventilate and save energy with the right windows
Long before the "hype" about "Fridays for future", households were already striving to be energy-efficient in order to save costs. Double-glazed thermopane windows are the result of such considerations. While masonry and roofs were well insulated, a lot of heating heat was lost through single-glazed windows for a long time. Especially after the introduction of central heating, this had a negative impact on the household budgets of normal families. It is also no coincidence that radiators and heaters are still mainly installed in front of windows today. Cooler air that falls mainly in the window area is thus immediately heated, rises upwards and thus ensures balanced room air circulation. For this reason, room temperatures are always measured at a height of 1 m above the floor in the centre of the room. Such precise measurements are seldom needed for private use, but occasionally play a role, for example, in museum exhibition rooms.
In private rooms, you are most likely to notice errors in room air circulation as soon as you have the feeling that a room is "cold underfoot". This is an indication that the room air is not circulating ideally and cooler air is being drawn downwards. Double glazing of modern thermopane windows closes the insulation gap and ensures that we lose little heating heat through the glass surfaces of the windows. The effect is directly reflected in heating cost consumption and saves money.
According to current building regulations, single glazing may no longer be installed in heated living spaces. These building regulations are well known to architects and craftsmen, and in the event of non-compliance, the craftsman would bear the responsibility. Breach of the building regulations in relation to glazing would not be a criminal or regulatory offence, but would be detrimental to any resulting insurance claim.
Ventilation
In order to maintain a healthy room temperature and air quality, it is imperative to be able to open windows and ventilate the room. Well-ventilated rooms make the air in the room fresher and prevent, among other things, mould growth on slightly damp walls. Furthermore, many domestic parasites are no friends of fresh air. Depending on their habits, all households will have their own individual ventilation habits. Important in ventilation is the habit of not running the heating at full blast at the same time, as the thermostatic valve located at the inlet is based on the room temperature and thus may blow the heating heat directly out of the open window. Such capers do not have a beneficial effect on the heating bill.
Almost all modern windows can be opened in different ways
We are all familiar with opening a casement completely or leaving it "tilted". As a rule, a tilt position is sufficient for balanced ventilation. You can also safely leave it open for a whole night or day without fear of unauthorised access to these open windows. The locking mechanism is designed in such a way that strangers cannot simply lever open tilted windows from the outside. The situation is quite different with smaller inhabitants. Squirrels and rats are perfectly capable of climbing up house walls and entering a flat through tilted windows. With squirrels, this danger is low. Rats, however, are quite devious when it comes to getting hold of possible food supplies. It is also no big problem for athletic cats to get outside through tilted windows. It is therefore advisable not to have windows open all the time or to keep an eye on possible animal activity. Windows that are open over the sash should never be left unguarded. Entire households can be transported away through windows opened in this way.
Saving energy with the right windows
Provided we can choose windows ourselves, it is possible to ask specialist dealers for insulation values and then adapt the choice to one's own heating behaviour. There are people who heat their living rooms to tropical conditions. Others, for example, hardly heat their bedrooms at all. We can take such considerations into account when choosing windows. Ultimately, the aim is not to lose heat through the window surfaces but to save costs.
For precisely this reason, single-glazed windows are no longer common and are at least disadvantageous. Too much heat escapes to the outside through a pane of glass. Architects make a similar effort with the masonry. Interstices are filled with rock or glass wool to improve insulation and thus save heating or energy costs. The tenant of a property cannot influence the elements, but would certainly be in a position to complain about defects.
Control, damage, maintenance
Homeowners, property managers and property owners are constantly required by regulations to carry out any renovations or improvements. Three or four decades ago, central heating replaced so-called night storage heaters and caused high renovation costs for many landlords, and now almost ten years ago, there was a widespread call to replace windows with wooden frames installed in the 1960s and 1970s with new plastic or aluminium frames, as many wooden frames had done their job over the decades and sometimes no longer sealed properly.
The list of possible damages in modern thermopane windows is comparatively small. Damage such as cracks or breaks in the glazing itself are actually only possible if objects hit the pane with great force. Bricks or other projectiles would certainly do the job. Larger birds deciding to break their necks at high speed on a thermopane pane also sometimes achieve glass breakage. A football fired by a child has little chance of breaking a thermopane pane. Pressure waves are also capable of breaking windows. Especially residents of cities with many unexploded aerial bombs may experience vibrating windows after a controlled explosion. Since bombs and meteorites rarely write their event radius in our diaries, it is sufficient to deal with more common damage. With constantly changing temperature fluctuations, such as prolonged exposure to sunlight, it can happen that the sealing layer that holds such thermopane glazing together becomes brittle. The result is an "air-drawing vacuum". With the air, moisture also gets into the space between the glazing, which will settle as soon as the temperature drops. The window fogs up on the inside.
Heat is also the reason for the fatigue of rubber seals, which close completely around the frame or sash on window sashes. Car owners may be familiar with this problem from the rubber seals of their car doors or the rubber of the wiper blades. Completely dried-out rubber seals harden, break and no longer seal. Such rubber seals are pressed in metres around the window sash and can be quickly replaced. Broken seals are most likely to be detected by a draught when the window is closed or by the appearance of moisture on the window sash or sill.
Damage can also occur to the closures and handles of modern thermopane windows. The fittings do not react well to rough shaking, especially as soon as something gets stuck. Jammed windows with plastic or aluminium frames usually have defective locking hardware. With wooden frames, the wood may have warped due to moisture and heat. Plastic and aluminium frames usually do not warp. Jamming windows then have their cause in the above-mentioned bent or broken fittings.
The maintenance of these elements is relatively unspectacular and can be done within a few minutes while cleaning the windows. We can oil closure fittings to prevent sluggishness, which could lead to breakage if handled too roughly. Rubber seals can also be regularly rubbed with an oily liquid to keep them supple. Utensils for the care of thermopane windows are available at reasonable prices. Care products for rubber seals as well as small bottles with oil are available in any car accessory or bicycle shop. You do not need any other tools.
We cannot protect ourselves against brick or bird strikes. However, it would be important to be more attentive to any fogging of the windscreen after such an impact in order to detect possible damage in good time. This can be difficult, especially in the warmer months of the year, because sunlight will not cause moisture to settle in the space between the panes. This only happens when the temperature drops noticeably. All these damages: panes, locking mechanism or rubber seal are - except for gross negligence - "material-related wear and tear". In this case, the tenant does not incur any costs in reporting the damage and repairing it.
In the case of cracked glazing, a small draught caused by a leaky seal or jamming, heating costs will not explode immediately. In order to avoid damage caused by penetrating moisture, for example, it is nevertheless advisable to report any damage to the owner or landlord in good time. If we are the owner ourselves, carpentry companies or installation glaziers are in most cases the right people to contact for any damage to a window.
Everything for low heating costs
As soon as energy supply companies announce an increase in electricity and heating costs, a collective resentment rumbles through the population. Saving such costs is therefore in the interest of all of us, and functioning thermopane windows help to avoid heating from an unsuitable window.
Requirements and building regulations
The building industry, as well as trade guilds or architects' associations, constantly keep an eye on developments in the market in order to be able to react with recommendations when action is needed. It is important to know that such recommendations do not automatically become regulations that are legally punishable in case of non-compliance. Most of the requirements are really just recommendations to ensure high functionality and quality for the consumer. If, for example, we were to develop a material that was visually similar to glass but had advantages in terms of resources, production or properties, it would only be a matter of time before glass windows were replaced across the board. Driven by precisely such associations. Conventional glass is nothing other than fused quartz sand, which we have plenty of on earth. In general, however, plastics might be cheaper to produce and less susceptible to damage. So the history of the window has chapters that have not yet been written. The past shows that innovation and inventive genius have repeatedly succeeded in replacing old materials with new innovations.
In window construction, the last major modernisation campaign was in 2011, when the building industry identified defects in wooden window frames from the 1960s and 1970s. Owners were asked to replace such old frames with newer plastic and metal variations, and across the country neither installation glaziers nor carpenters could complain of a lack of orders.
The next stage will follow, but the timing is not yet clear. The only thing that is clear is that the lifespan of modern plastic frames is longer than that of the wooden frames used in the past. Wood reacts much more sensitively to weathering. The result was cracks or warping that eventually caused the window to leak. This danger does not exist with plastic frames. It remains to be seen how long it will take before the first material fatigue occurs, which will then probably require replacement of the rubber seals or closing mechanisms. Experts already know from comparable seals from the automotive industry that seals can certainly remain undamaged for several decades.
The glass of the panes themselves will be able to survive for centuries. However, the thermopene effect is not guaranteed, since the panes are glued together by a silicone-like plastic compound. Even laymen will understand that the life span of such adhesives is shorter than that of the glass itself. Current comparative figures are not yet available to the market, as possible material fatigue is highly dependent on locations and local characteristics. For example, if there is regular intense sunlight or longer periods of frost, the life of the window and frame will be less than in a moderate climate.
Important in this context is the responsibility, or liability, of such damage. In almost all cases, tenants are not liable for repair costs. Especially as soon as it is a matter of damage such as material fatigue or wear and tear, which can occur over the years even with conscientious and responsible use and almost certainly will at some point. Liability is then assumed by the owner or lessor. Unless the company that carried out the assembly and installation has agreed a warranty period with the owner and the damage is within this period. In such cases, the relevant tradesmen will be called upon to bear the costs. The tenant's task and responsibility is then merely to report such damage promptly. Except for the "air draft" of thermopane windows in the warmer season, all other damage will provide visible indications relatively quickly... such as draughts or visible moisture in the window area.
Conclusion
Windows not only guarantee a view outside, they also flood our living spaces with light and save energy. At the same time, windows are available in all kinds of shapes and designs to suit our taste in design as well.
When choosing the right windows, there are several other factors to consider. The regionally varying building regulations and the influence on the statics of buildings alone are reason enough to discuss them with experts. Architects, window manufacturers and craftsmen are the right people to talk to about this.
To ensure that our windows last as long as possible, very little maintenance is required, which we can all do without a great deal of effort, so that the "view" remains good in the future.
