A window frame system for fixing at least a first panel, includes at least a first window frame structure which includes at least a first window frame profile having at least first and second holders, and at least a first thermally insulating element with sixth and seventh holders. The second holder and the sixth and/or the seventh holder of the first thermally insulating element include at least one internal corner with a radius smaller than 0.5 mm. In this way, the dimensions of the window frame profile may be smaller than in the known window frame profiles. This may be advantageous for the total insulation value of the window frame system and the quantity of material required/used for the window frame profiles. Also disclosed is a thermally insulating element, a method, a window frame structure, a flexible profile, a control system and a sun protection system.

A window frame system for fixing at least a first panel, includes at least a first window frame structure which includes at least a first window frame profile having at least first and second holders, and at least a first thermally insulating element with sixth and seventh holders. The second holder and the sixth and/or the seventh holder of the first thermally insulating element include at least one internal corner with a radius smaller than 0.5 mm. In this way, the dimensions of the window frame profile may be smaller than in the known window frame profiles. This may be advantageous for the total insulation value of the window frame system and the quantity of material required/used for the window frame profiles. Also disclosed is a thermally insulating element, a method, a window frame structure, a flexible profile, a control system and a sun protection system.