This paper aims to show the preferred combinations of illuminance and color temperature under various daily activities in residential houses. Subjective experiments were carried out using scale models illuminated by RGB fluorescent lamps with the dimmer. "Preference", "Brightness", and "Naturalness of color appearance" were evaluated as the scenes of "Relaxing", "Getting together", "Dining", "Cooking", "Learning", and "Resting (before retiring)". 25 combinations which consist of 5 illuminances (501x, 1001x, 2001x, 4001x, 8001x) and 5 color temperatures (3000K, 3500K, 4200K, 5000K, 6500K) were investigated. Preferred combinations of illuminance and color temperature vary according to the activity. The results show that the traditional Kruithof's curve is not necessarily effective under various scenes in the residential houses.
