External venetian shading

The physics, briefly

An internal blind can only reflect or absorb sunlight that has already passed through the glass, and whatever it absorbs it re-radiates into the room. An external blind stops it in the open air. The difference on a big north-facing ridge window is not subtle; it is the difference between a lounge you can sit in at three o'clock and one you cannot.

Why venetians rather than a solid screen

Because they tilt. Wide aluminium slats set at the right angle intercept the high summer sun while leaving a clear horizontal band of view straight through — you keep the city bowl and lose the glare. In June, with the sun low, the same slats open flat and let the winter warmth in on purpose. That seasonal control is why this is the specification architects put on ridge houses.

Built for weather, run by sensor

These are engineered systems, not a blind hung outside. Slats are extruded aluminium, guided in side rails or on tensioned cables, and they retract into a slim headbox. Motorisation is standard, with a sun sensor to close them before the room heats up and a wind sensor to retract them before a highveld thunderstorm arrives — which matters when the storm arrives at four and you are still at the office.

Practical notes

• Best specified at design or renovation stage, so the headbox is planned into the facade.
• Retrofit is possible on most masonry elevations; we survey the fixing before quoting.
• Powder-coated to a chosen colour — useful where a street or a complex expects a consistent look.
• Pair with an internal sunscreen roller for night-time privacy; the two do different jobs.
• Where the elevation cannot carry a headbox, roller shutters or a zip screen may fit better.