External solar protection is always the most effective because it stops the sun's rays before they heat up the glass. Wilms outdoor screens keep up to 90% of the heat out. For terraces, an articulated-arm screen works best, and for verandas, patio sun shades are the right choice.
In most cases, solar protection does not require a permit: screens and articulated-arm screens can usually be installed freely. For fixed constructions such as a terrace roof, a permit may be required. Always check the local rules with your municipality.
Dark screens generally block more heat and sunlight, while lighter colours let in more daylight but keep out slightly less heat.
Many people think white works best because of reflection, but in practice darker fabrics keep more heat out because they absorb more sunlight. The right balance depends on your preference between daylight and heat protection.
With proper maintenance, Wilms solar protection lasts on average 20 years. It is strongly recommended to clean the fabrics regularly and have the mechanism checked annually to significantly extend its lifespan.