External accessories for Skylights and Roof Windows

External accessories for Skylights and Roof Windows

Protection from overheating...

According to the DIN 5034-1 norm rooms should be protected from overheating with the use of external accessories (awning blind, roller blind) which give better protection than internal accessories.

FAKRO, to improve its products and increase the comfort of users, is constantly analyzing the effectiveness of protection from the heat using different shading devices. To this end, there have been prepared eight exactly the same research rooms, which are identically exposed to sunlight and equipped with the same roof windows. The study was performed with closed windows. The temperature was measured at several points, one meter above the floor. On the windows, there were mounted different accessories and the results of the research are presented in the chart.

Protection from overheating


The investigation results above show clearly that external accessories (awning blind and roller shutter) provide the best protection from outside heat. The optimum sun protection can be acquired be external awning blind, bearing in mind heat protection and ease of installation. Internal accessories also offer protection from the heat but to a lesser degree than external accessories; their main function is to decorate the space and regulate the amount of light entering the room.

Solar energy transmittance

Heat radiation in %

  1. window without blinds g = 61% ( 0.61) according to EN 410

  2. window with intnernal black-out blind g = 37% (0.37) according to EN 13363-1

  3. window with awning blind depending on type of fabric g = 4-14% (0.04 − 0.14) according to EN 13363-1


Solar energy transmittance1

Solar energy transmittance2

Solar energy transmittance3


The external awning blind together with an internal accessory installed on a FAKRO roof window creates a set of accessories which ensure the highest levels of comfort in the loft space, because they protect from heat and light and decorate the room.