Guides
Why does an exterior blind protect better from heat?
Quick answer
Exterior solar shading limits overheating by intercepting solar radiation before it passes through the glazing. External venetian blinds add useful control by blocking direct sun while admitting diffuse daylight. Actual performance depends on the system, orientation, time of day, wind and operation.
Why the exterior position matters
Once sunlight passes through glazing, part of its energy warms interior surfaces and air. Exterior shading acts earlier. Interior blinds still help with glare and privacy, but thermally they act after the glass.
Match the solution to orientation
South facades receive higher sun, while east and west facades experience lower morning or evening sun. Recesses, balconies and nearby buildings also alter exposure, so each facade should be assessed separately.
Venetian blind, roller shutter or awning
External venetian blinds suit spaces where daylight and view should remain adjustable. Roller shutters close more completely. Awnings mainly shade terraces or balconies and may also reduce sun on the glazing behind them, depending on size and orientation.
Shade at the right time
Shading is more effective when positioned before the glass becomes strongly heated. Timers or sensors can improve consistency when thresholds and wind protection are suitable for the product.
Retain daylight and ventilation
Correctly angled slats reflect direct sun while admitting diffuse daylight. When outside air becomes cooler in the evening, ventilation can complement shading where the building allows it.
What an on-site review establishes
Around Biel/Bienne, Brügg, Bern, Fribourg and Neuchâtel, solar and wind exposure vary by facade and site. An inspection checks fixing points, guidance, dimensions and controls.