&nbsp;Introduction<br>&nbsp;Lately, a case that parcel out the land into small plots become increasing, especially in large cities in Japan. A crowded residence area and a narrow site that a device with a design is needed are very common. Therefore, we should devise methods for increasing living comfort in a small house, and consider about the space based on personal space, privacy and the like. The purpose of this study is to investigate the method of usage of small spaces (about 10 square meter) that is divided horizontally above and below. Such space is effective on a crowded space, perhaps.<br><br>&nbsp;Method<br>&nbsp;For this study, we designed and made a original loft space with wood. That set up at enviromental psychology laboratory, SHINSHU Univ. The floor space is about 10 square metre, and we are able to move the floor that is divided horizontally above and below from 950mm to 1550mm (5 level). First, subjects experienced the experimental space about 15 seconds and evaluated their impression on 7 topics (spacious, oppressive, comfortable, calm, anxiety, fun, like) for each space. Then, subjects answered which space is more appropriate to each behavior (eat some food, change one's clothes, study hard, relax, sleep).<br><br>&nbsp;Result and Discussion<br>&nbsp;The results were summarized as follows:<br>&nbsp;1) Subjects had a preference for the upper space and the space of higher ceiling (over 1400mm).<br>&nbsp;2) The space that feel more appropriate to behavior depended on ceiling height and position (above or below). For example, the lower space is more appropriate to study hard. On the contrary, the upper space is more appropriate to relax.<br>&nbsp;3) Plenty of ceiling height (over 1100mm) was necessary for change one's clothes, and lower ceiling (under 1100mm) were preferred to sleep.<br>&nbsp;4) Subjects estemated the upper and lower space equally when the difference of ceiling height was under 300mm.<br>&nbsp;5) The behavior and condition (the space of ceiling height) which indicated stronger relationship were a combination of "relax/study hard" and "1100mm/1400mm", and "sleep/study hard" and "950mm/1550mm".<br><br>&nbsp;Conclusion<br>&nbsp;As the tendency of the whole, subjects prefered the higher ceiling, but that preference was not stable. Most people prefer spacious room, the more the ceiling become high, the more subjects estimate comfortable, although there is appropriate size for the purpose and something. Consequently, the lower ceiling is not always denied. We will continue to investigate about the relationship between the volume of small space and behavior, and attempt to devise methods for increasing living comfort in a small house.