Field Survey on Actual Conditions of Light Environment in Mid-scale Office Buildings in Japan

Abstract

Questionnaire and field measurements were conducted to identify the light environment and the occupants' visual comfort in mid-scale office buildings in Japan. The answers of the questionnaire were obtained from 389 workers in 77 different buildings. The results have identified that more than 60% of the occupants attended to their work at their own desk in over 80% of working hours. Also, it was identified that only 10% of the occupants used task lighting. On the other hand, 90% of the occupants answered that they always turned on the ceiling luminaires. Field measurements were conducted in 9 different office buildings to identify the actual conditions of the environment around the windows. As results, it was identified that the percentage of the occupants who were dissatisfied with windows became higher in the cases where they could see nothing from the windows because they were covered by furniture, documents and so on placed around them than when they had an outside view through the windows. Over 30% of the area within the windows was hidden by furniture or documents in more than 30% of the measured buildings.