Installing roof windows Functions, planning & Co.

A pleasant incidence of light always creates a good living atmosphere in the home. Therefore, both the choice of windows and their correct placement are crucial. This especially applies to potentially darker rooms such as those under the roof. If you want to expand your attic, you should definitely install skylights that provide sufficient natural light. In this article we will tell you about the most common types of roof windows, how to plan their installation and what financing is available.

Which roof windows should you install?

Windows perform a number of important functions: they provide natural lighting, allow regular ventilation of rooms and offer a clear view to the outside. Matching windows are also available for all roof variants. But which type of window is suitable for your home? When installing roof windows you should consider their respective functions and coordinate them with your personal needs and preferences.

Types of windows and their functions

• Casement window: These windows are fixed to the frame at their central axis and can therefore be opened both inwards and outwards. Thanks to their height they are perfect for attics with tall furniture, as they do not collide when the windows are opened. If you are planning a children’s room under the roof, casement windows are also suitable, as children have difficulty reaching the handles.
• Folding casement window: Unlike pivot windows, pivot windows are attached at the top edge so that they can be easily opened from below with one hand. Its large opening angle allows for an excellent view and also visually expands the room. To get even more daylight, it is best to install two top-hung windows when roof windows are installed.

• Roof exit window: As the name suggests, the roof window allows safe exit to the outside. This is especially relevant in everyday life for roofing craftsmen and chimney sweeps. However, the roof window can also serve as an emergency exit for the occupants of the house.
• Panoramic roof window: The larger the window, the more natural light it lets in. So, if you like light, you should consider a picture window. This large glass façade made up of one or more window elements is particularly useful in attics with a splendid view.
• Overlapping glass: The ridge of the glass roof lets a lot of light enter the room from above, ensuring complete lighting. This means less electricity is needed, which reduces electricity costs in the long term.
• Bright band: A so-called light strip provides additional light into the room. This narrow additional window is installed under regular windows, which requires the window surface to be extended to the floor. The light band allows only a limited view, but instead illuminates the usually dark corners of the attics.

You should keep this in mind when designing your roof windows

If you plan to install roof windows, you should not only consider their function, but also their subsequent accessibility and compatibility with the desired home decor. The intended purpose of the room is crucial here. Do you need a lot of shelves or do you just need a well-lit work surface? Tall furniture also requires tall windows to avoid obscuring it, and with low windows you should leave plenty of space. Additionally, you can use the following aspects as clues:

• For ideal light incidence you should Skylights in different directions they installed. This way the room is not completely in shadow when the sun moves.
• The slope of the roof determines the required length of the windowsbecause steeper roofs get enough light even with shorter windows. Flat roofs, on the other hand, require longer windows so that enough light enters the room.
• Windows can visually enlarge rooms. Especially small attics benefit from several windows. These can also be installed next to each other, giving the impression of a front window.
• One is considered common Window height between 90 cm and 200 cm Measured from the top edge of the window to the floor. Anything beyond that is difficult to achieve and should therefore be carefully thought out.

Further information on window design, even on lower floors, can be found in the section “Window design made simple – everything you need to know”.

Financial support for new roof windows

If you have new roof windows installed in your home, you should find out whether you can receive a subsidy from the state for your construction project. For example, if you want to reach the KfW Efficiency House standard through an energy-efficient renovation, KfW will issue subsidized loans that will also serve to finance your windows. The Federal Office for Economic Affairs and Export Control (BAFA) currently promotes individual measures. For example, roof windows are subsidized if they are replaced as part of a building envelope renovation project, especially if they close more tightly than before and minimize thermal bridging. If you do not apply for state financing, you will later be able to deduct the renovation costs from your taxes. The “tax reduction for energy measures in private residential buildings” in the Income Tax Act (EStG) has been in force since 2020 and is valid until the end of 2029.

Installation of roof windows: is building permit required?

If you subsequently install roof windows, for example as part of a roof renovation or an attic extension, a building permit may be required depending on the regulations of the respective federal state. According to state building codes, the installation of roof windows requires approval. as soon as the roof surface is changed or the statics of the building are compromised. It is therefore best to ask the local building authority whether a building permit is required. If necessary, request it from the building authority. Processing time usually takes 3 months.

For further reading

Has your roof already been taken off and you just need to make it comfortable? In our article “Furnishing and designing attic rooms” you will find numerous tips on how to ideally set up your attic rooms and visually create more space.