This paper investigates the effects of the illegal occupation of part of the Rubem Berta housing estate in Porto Alegre, Brazil, on residents satisfaction, attitudes and behaviour. The illegally occupied four storey blocks of flats were uncompleted at the time of the occupation. A comparison is made between the degree of satisfaction, attitudes and behaviour of those living in the uncompleted and occupied part and those living in the completed and commercially sold section of the same Rubem Berta estate. Both dwelling aspects and housing estate aspects are evaluated in the two sections. Questionnaires, interviews, and observations were used as data gathering methods in the Rubem Berta estate. The results show that the main dwelling and housing estate aspects affecting user satisfaction, attitudes and behaviour in the uncompleted and occupied four storey blocks of flats are similar to the aspects affecting those living in the completed and commercially sold four storey blocks of flats. Nonetheless, levels of user satisfaction with many dwelling aspects and housing estate aspects are quite different, due, mainly to the tolerance of the problems by those who went through the difficult process of housing occupation.