Abstract
The Improvement of the living environment of the block is expected as the result of the improvement of the narrow roads condition in the block, which depends on the setback in the individual site. In this study, through the observation of the change of narrow road condition in Ashiya, the factors the effect the improvement of block condition are discussed concerning the size of the block, road pattern in the block and numbers of the sites on the narrow road. It is clear that the improvement of the block condition is much affected by the way of individual setback and that of the corner site, and it is necessary to have block plan for improvement.