Brise-soleil (sun shading)

A brise-soleil, French for sun breaker, stops sunlight before it reaches the glass. Fixed concrete or metal fins, timber slats, perforated panels or movable louvres can all do the job. Le Corbusier made it a defining element of his buildings in hot climates. In Turkish it is called güneş kırıcı.

Matching shading to orientation

How well a brise-soleil works depends on which way the facade faces. In the northern hemisphere the summer sun is high on south facades, so horizontal overhangs and louvres are effective, while the lower winter sun can still slip underneath and warm the rooms. On east and west facades the sun comes in low and from the side, and vertical or adjustable fins work better. Shading placed on the wrong facade cuts daylight without stopping the heat.

Why outside rather than inside?

• External shading stops heat before it passes through the glass; internal blinds only act once the heat is already in the room.
• Lower cooling loads translate directly into lower energy use.
• Glare is controlled and daylight inside becomes more even.

Sun shading gives a facade strong rhythm and depth. In a render, the striped shadows that fins cast across the facade and into the interior can become the most striking part of the scene once the sun angle is set right.