Type F

Type F flat roof windows

The type F flat roof window features a sleek modern look, characterised by excellent thermal insulation parameters. The structure of the frame is the same as for flat roof windows with a dome however the main difference lies in the glazing unit which is bonded using modern manufacturing technologies to produce a highly aesthetic and innovative design.


Type F flat roof windows

A minimalist and perfect designed DEF flat roof window has been awarded with prestigious Red Dot Design Award.



The innovative flat roof window D_F ColourLine allows you to match the colour of the window finish with the existing roof design. A wide range of colours in accordance with the RAL Classic Palette. The D_F aluminum window profile is finished in RAL 9005 (black).

DEF colourline


DEF solar image


The autonomous DEF Solar window is powered by solar energy through the special PV panel, therefore the product does not require connection to the electrical system in the building. The PV panel integrated with the battery allows for operation even on cloudy days. Proven design ensures excellent performance and impeccable aesthetics. Convenient operation with the wireless Z-Wave system using the remote control. Remote control is included to window.


The type F is equipped with an energy-efficient, triple DU6 glazing unit. The external glass 6mm thick is toughened while the internal glass is laminated and anti-burglary P2A class. Should the pane crack, shards of glass do not pose a danger but remain on the laminate film. Heat transmittance co-efficient for the whole window is U=0.70 W/m2K (to EN 14351-1). The window is also available to order with a quadruple U8 glazing unit. Heat transmittance co-efficient for the whole D_F DU8 window is U=0.64 W/m2K (to EN 14351-1). Such excellent parameters make the window suitable for use in energy-efficient and passive buildings.


The DEF flat roof window with a double-chamber DU6 glazing unit has been tested for sound insulation during heavy rain. The result obtained, LIA= 36 [dB]* confirms the high level of resistance against sound penetration, therefore the window is ideal for places where peace and silence are welcome. 

*as per ISO 10140-1/A2:2014; The result also applies to windows: DXF DU6, DMF DU6, DXF SECURE (PK) DU6, DMF SECURE (PK) DU6, DRF DU6

The structure of the window enables installation of internal as well as external accessories. The external awning blind protects against room overheating while internal accessories protect from intensive sun light and provide a decorative element.


The type F flat roof window is suitable for roof pitches between 2 and 15 degrees.


The wide range of sizes available has been matched to standard skylights, enabling the quick and easy replacement of an existing skylight for a new window.