Exterior screen, outside mounting, outside frame – what's it actually about?
The term "exterior screen" (German: "Außengitter") keeps coming up in search queries and consultations. It almost always means one thing: a fly screen fitted from outside onto the window frame – as opposed to the classic inside fitting in the window rebate.
In this guide we explain what the difference is, when outside mounting makes sense and when it does not.
Inside vs. outside mounting – the basic principle
With a fly-screen fixed frame there are essentially two mounting locations:
Inside mounting (standard): The fixed frame sits in the window rebate, i.e. on the inside of the window frame. When the window is opened, the sash swings inwards and the fly screen stays in place. This option is the right choice for around 90% of all home situations in Germany.
Outside mounting (exterior screen): The fixed frame sits on the outside of the window frame, often into the render or resting directly on the frame. This option is used in special cases where inside mounting will not work.
When does outside mounting make sense?
In practice there are a few typical situations in which we recommend or even prefer outside mounting:
1. Outward-opening windows (rare in Germany, more common abroad) In Germany, windows almost always open inwards. In some older buildings or with special window constructions – for instance old wooden windows with outer sashes – the fly screen has to sit on the outside because the indoor space must be kept clear.
2. Very narrow window rebates With some modern slim-profile windows, the inside rebate does not offer enough space for a fixed frame. Here, a frame mounted on the outside is the only solution.
3. Roof windows (Velux, Roto) Special insect-screen rollers for roof windows are usually fitted on the outside of the frame. With classic fixed-frame solutions, outside mounting can make sense here.
4. Very large openings / large doors For extra-large openings – such as lift-and-slide doors – sliding screens are often the better choice. These are sometimes guided on the outside.
5. Window sills or fittings that get in the way indoors If you have a wide internal window sill, a fixed privacy screen or plants right next to the window, an outside-mounted screen can be the better option.
When is outside mounting **not** recommended?
In most cases, inside mounting is the better choice. Outside mounting has a few disadvantages to keep in mind:
- check_circle**Weather:** The frame is directly exposed to UV radiation, wind and rain. High-quality aluminium profiles cope with this, but cheap plastic frames quickly become brittle.
- check_circle**Cleaning:** Anyone living on a higher floor finds it harder to reach from outside. Inside mounting makes cleaning considerably easier.
- check_circle**Theft protection:** In ground-floor flats, an outside-mounted screen can be removed more easily than one sitting in the rebate.
- check_circle**Appearance:** Outside-mounted frames are visible from the street. Inside-mounted fixed frames are almost invisible.
- check_circle**Permission in rented flats:** Outside mounting can count as a structural alteration – this has to be clarified with the landlord.
Special case: outside-mounted roller insect screens
Roller insect screens are usually mounted outside on the facade. The cassette sits above the window and the mesh is pulled down when needed.
This is a special form of "outside mounting" that differs from a classic exterior screen:
- check_circleThe mesh is not permanently tensioned
- check_circleIt can be retracted when needed
- check_circleIt also provides additional protection from sunlight
- check_circleThe cassette is visible but the mesh itself is unobtrusive
For families with children, allergy sufferers or people who want to switch flexibly between insect protection and a clear view, this is a very popular option.
Which system suits your situation?
Most of our customers in Waltrop, Dortmund, Bochum, Hagen and across the Ruhr region decide, after the consultation, in favour of inside mounting with a clip-on system. It is:
- check_circleVisually unobtrusive
- check_circleDrill-free and therefore ideal for rented flats
- check_circleQuick to fit (under one minute per window)
- check_circleEasy to clean (can be removed without a trace)
If, after taking measurements, we find that outside mounting suits better, we will suggest this – with an appropriately high-quality aluminium outside frame that still looks immaculate years later.
On-site advice makes the difference
The question "inside or outside mounting" is best answered directly at the window. We come to you free of charge and without obligation:
- check_circleWe look at the window rebate, sash and frame
- check_circleCheck whether the rebate is deep enough for a fixed frame
- check_circleTake your home situation into account (rented or owned, floor level, appearance)
- check_circleRecommend the system that fits best in the long term
Whether you are searching for "exterior screen", "outside-mounted fly screen" or simply "made-to-measure insect protection" – we bring clarity to the terms and supply the solution that suits your window.
We look forward to hearing from you – by phone, by email or via our contact form.