Tilt and turn windows: What are they?
Like so many things in Germany that work properly tilt and turn windows are made differently. The driver for this is partly due to Germany energy conservation laws having a higher standard than the UK, but also due to the fact that the German consumer is always looking to the long term. For a product that will last a long time, not just 5-10 years. By law, a product used in a home must be fit for purpose for a long time. Unlike the UK, where “fit for purpose” usually means that it’s operational when new and only a short period (usually a year) after. Many manufacturers have bold claims such as 50 year guarantees. But, when you read the small print, these are so conditional and often mean little practically.
Tilt and turn windows are the norm in Germany and many other northern European countries, where the winter weather is much colder than in the UK.
Tilt and turn how do they work
A tilt and turn window fundamentally opens on two axis: tilting when ventilation needed and turning mainly to provide a means of escape from a room in case of fire. Quite different to the more commonly found UK windows.
In the tilt position, the window tilts inwards into the room – remaining fixed at the base. This allows ventilation but keeping a good level of security and also shielding off rain. Our heavy duty window opening mechanisms provide security even when open.
Tilt and Turn Mechanism
The very same tilt and turn mechanism allows insertion of 3 butyl rubber seals in the window between the frame and the opening sash with an external seal, mid window seal and inner seal. Many non-tilt and turn manufacturers are limited to one or two seals due to the constructional make up of the frames and reluctance to have additional machining costs of making this feature. Essentially, the cold air is kept at the outside of the window frame and not to the inner edge.
- With windows tilting inward, they can be used to ventilate in bad weather and be opened with lesser risk of break in. The tilt function usually opens 5-10cmm so not enough room to climb of reach through.
- The turn function is operated by putting the window handle in the 2nd of its two positions. This allows the window to be cleaned from the inside of the building.
Could Tilt and Turn Windows Benefit you?
Fundamentally, tilt-turn windows and doors offer:
- Better air tightness due to the locking points and rubber seal that runs around the whole perimeter of the window. Thus pulling the window sash tightly into the window frame.
- Lower thermal gradient in the window frame. A tilt and turn window can have up to 4 airtight seals across the frame. Most normal UK windows have just one. Don’t be confused by flap seals around the external perimeter of the outer frame, which have cut-outs for drainage. This is just a weather seal. They allow cold air to get right into the gap between the opening sash and the window.
As a result, the distance between outside air at 0c and inside air at 20c is only the width of the airtight seal. With most tilt and turn windows having 2-3 seals the inner chamber behind the first air tight seal is often 12c/15c (using the example above) and the thermal gradient is gentle. The frame is thus warmer and the window has better performance
- Opening inwards, NOT outwards. For many, there is a gasp of disbelief that someone could have a window that opens this way, as they would not be able to use the window cill inside to place the precious wedgwood artefacts. In Germany, window cills are used in the same way as the UK. The window is used 99% of the time only in the tilt position, thus allowing our cultural love of cluttered window cills to continue.
- Many German style tilt and turn windows have thick chunky frames. That’s simply the style in Germany. In a house with large openings, the strong engineered frames can allow large maximum sizes.
But often, these are not suitable to retrofit into a UK home with normal windows: if the window is small, the frame size is still chunky and results in less glass.
However, some of the Danish tilt and turn units offer slim frames – providing a happy medium suitable for UK houses.
Are your windows energy efficient?
There are a few different types of condensation, have you ever spotted that condensation around the edge of the glass near the frame on the inside? This is partly caused by cold air being deep inside the frame. A cold bridge is created, making the inside of the window frame cooler. This is not good for energy efficiency, or the air-tightness of your windows. Tilt and turn windows essentially shut like a bank vault in terms of their overall efficiency.
A really good quick test of the energy efficiency of your windows is to take an incense stick around the frame of your window and float a line of smoke around the window. On windy days, you will see the smoke move not only around the window, but also test the area between the wall and the window, underneath the window board (or internal window sill). See the smoke move and you know you have air leakage from the outside into your home.
Our performance windows are enhanced by our German standards of installation. It’s not just about the window, it’s equally about how it’s installed.
Our customers tell us that our understanding of construction and windows and doors make us quite unique.
Replacing your windows with Tilt and Turn
What to look our for
Timber and composite tilt and turn windows are by far the most popular in the UK. But aluminium is considerably cheaper. Often, this is a lure. As many aluminium frames suffer with condensation, despite the inclusion of a thermal break. The window frame is the cold part of the room. Think long and hard before putting aluminium windows into a property.
Modern buildings are airtight and air quality with moisture content must be managed. In countries where tilt and turn is popular, so is MHVR. Therefore, the need for trickle vents is avoided. It has always seemed rather ironic to spend a lot of money on new performance windows to then create a hole for ventilation. Building Regulations require ventilation from one of those options.
If using tilt and turn windows from Europe, many self builders get caught out by not buying windows that comply UK regulations. In a new build property, windows and doors must be Part Q compliant for security. It is wise to seek help and assistance from UK companies, with UK staff and UK aftersales. Horror stories of self builders who try to buy windows directly from Estonian, Latvian or online German window shops are not uncommon and often result in windows being rejected by building control. Getting professional help on specification is essential to avoid this. Be wary of supply-only companies who don’t supply and fit as a single package. They usually don’t want to fit because they don’t have building experience and don’t want the risks; they would much rather you take them.