Background: Following the spread of dissatisfaction with modern architecture, the machine attitude towards man, and the disregard for human values ​​and human existential dignity, the global movement in support of independence and participation was formed in response to demographic and social realities. Recognized in 1988 as universal design, the movement allowed more people of all levels of ability to live freely and independently. This article seeks to investigate the ethical dimensions of universal design and strengthen them in public spaces to improve the level of social interaction, to provide conditions for the fair use of environmental facilities by humans. In this regard, with the pathology of the causes of poor social interactions in public spaces of Tehran and the inefficiency of existing laws in this field, ethical design strategies based on universal design criteria have been developed.
Conclusion: Findings show that the obstacles facing the target groups in their direct and free presence in the environment, arise from the lack of professional ethics in the three stages of design, reconstruction and operation period and reduce social interactions and unwillingness of people with disabilities to participate actively in society. On the one hand, it is rooted in the cultural issues of the society and the lack of ethics in designing public environments, and on the other hand, it is related to the lack of an ethically integrated approach in decision-making of city officials.