This study introduces a progressive assessment based on control lists of different accessibility criteria to fit adaptability to wheelchair users in housing environments. Assessment for accessibility in housing settlements has four different levels of study. Every study level covers some criteria for accessibility in related spaces, environments or building elements. General settlement criteria, criteria related with near environment of buildings, criteria for lateral and vertical circulation, and criteria for usage in space are considered in this study. A case study has been applied in a mass housing settlement in Istanbul. The mass housing settlement has been evaluated by the assessment model as to whether it is suitable to adapt to wheelchair users or not. (C) 2001 Elsevier Science Ltd. All rights reserved.