Valaistustasoon

Valaistustasoon is a concept used in Finnish architectural and interior lighting design to describe the target level of illumination for a space. It denotes the amount of light on a defined plane, typically the working plane, and is expressed as illuminance in lux. The specified valaistustaso depends on the tasks performed, the time of day, and user comfort, and it is achieved through a combination of daylight and artificial lighting.

Illuminance is measured with a light meter placed on the working plane, usually around 0.75 to 1 meter above the floor. The same space can have different target levels for different areas or activities, such as desks, reception, or circulation zones.

Standards and guidelines influence valaistustaso targets. Internationally, standards such as EN 12464-1 specify recommended illuminance ranges for indoor workplaces, while national bodies translate these into local requirements. In addition to illuminance, designers consider color rendering and color temperature to ensure the perceived brightness aligns with the task.

Design approaches emphasize daylight integration, appropriate luminaire layout, and control systems to maintain the target level while reducing energy use. Adaptive lighting, occupancy sensors, dimming, and daylight-responsive controls help sustain the desired valaistustaso under changing occupancy and natural light conditions.

Maintenance, aging, and dirt accumulation reduce luminous output, so regular verification and re-aiming or replacement of luminaires are part of efforts to keep the valaistustaso as specified. The concept is closely linked to lighting quality and occupant comfort as well as energy efficiency.