Varjostins

Varjostins is a Finnish term for shading devices used in architecture to control sunlight and glare. They may be external or internal and can be fixed or adjustable. The primary purpose is to reduce solar heat gain, minimize glare, and support daylighting strategies while preserving view and aesthetics. Common forms include external overhangs, horizontal or vertical fins (louvers), external blinds and shutters, and internal roller or pleated shades. Materials range from aluminum and steel to wood and fiber-reinforced composites; many systems incorporate weatherproof coatings or powder finishes for durability. External shading devices are typically more effective at blocking direct sun because they intercept light before it reaches the glass, whereas internal shades offer finer control of daylight and privacy.

In design practice, varjostins are selected based on climate, orientation, and project goals. South-facing façades often employ shading fins or overhangs sized to block high-angle sun in summer while permitting low-angle winter sun. In temperate and Nordic contexts they contribute to energy efficiency and comfort without compromising daylight. Modern systems may be motorized or integrated with sensors and building management systems, enabling dynamic adjustment in response to sun position, occupancy, or energy targets.

Etymology: The word varjostin comes from varjo, meaning shadow, and denotes a device that creates shade or reduces direct sunlight. The plural varjostins refers to multiple such devices.

See also: shading device, louver, sun shading, daylighting.