In this paper, we aim to show the trend of conversion from buildings to theatres and halls for people who are planning to convert buildings in Japan. To study our theme, we investigate things about conversion from buildings to theatres and halls in U.K and process data to draw graphs. Our study is made on 1165 venues in British Performing Arts Yearbook 2000/2001 and based on the book, websites of venues, questionnaire via e-mails, interviews to venues in London and former study. At the result, 35% venues are converted and those most audience capacity is less than 400. Especially, venues converted with change of their use are 22.4% and it is the most in conversion.