This article clarifies the changes of 'place-constructing' by office workers around their workplaces during an office-moving as environmental transition from Kanda (a mixed-used downtown area in Tokyo), to Shinagawa (a newly redeveloped area in Tokyo). The methods were interviews and questionnaires about places of frequent use, dropping in, refreshing at, feeling 'mine', and routes for commuting and strolling. The findings are as follows: 1) The ways of 'place-constructing' in each area are different. 2) In an office with various advanced functions in the newly redeveloped area, 'semi-third places' are constructed. 3) There are complementary relationships between 'third places' and strolling routes, as well as between 'semi-third places' and commuting routes. 4) At a small office in the mixed-used downtown, some workers take their works out to 'third places'.
