The article highlights the acute problem of the formation of architectural and object-spatial environments of penitentiary institutions in Ukraine. Today the correctional system in the state is improving and bringing Ukrainians closer to a safer and more tolerant society, but the problem of functioning of existing places of detention remains. Predominantly they are morally and materially obsolete buildings with problems of compliance with technical, sanitary, and hygienic standards, as well as the unsatisfactory functional and aesthetic organization of space. The article considers the problems of harmonizing the architectural environment of domestic correctional complexes, in particular, the design of interiors and furnishing of premises for the detention of persons deprived of their liberty. There is no objection that the complex design of a correctional facility building and interior design of premises for the detention of arrested (imprisoned) persons should be based on versatile requirements reflected in the normative documentation. Today in Ukraine there is a development of normative construction documentation for the design of premises for the detention (accommodation) of persons subject to isolation, based on the current state documents of the Ministry of Internal Affairs of Ukraine, the National Police of Ukraine, the State Migration Service and the like. This rather wide range of documents, relying in turn on international provisions, puts forward requirements not only for the design of sites and buildings for the detention of persons in isolation but also for a certain interior design and equipment of the premises. The study and analysis of the available examples of world experience in the design and construction of penitentiary institutions can show a direct link between the design of the premises where prisoners are kept and the methods of re-socialization and re-education, the positive results of which are an important goal of the functioning of such institutions in socio-economically developed countries. The experience of designing, constructing, and operating foreign prisons and correctional centers of various security levels has been studied and analyzed, and the peculiarities of interior design and equipment of premises (cells) for the detention of the contingent have been revealed. It was found that the more qualitative the process of socialization in a safe and humane environment of places of deprivation of liberty, the lower the percentage of recidivism achieved under the influence of this environment, the higher the justification of state expenditures in this subsidized sphere. The article highlights several regulatory requirements and provides recommendations on the formation of a subject-spatial environment for the detention of persons in correctional institutions in Ukraine. The result of this research can be several conclusions, guided by which, it is possible to form a full-fledged object-spatial environment for the detention of prisoners (arrested) in a correctional institution, as well as to design interiors and furnishings for the staff, whose work is difficult and stressful.