**4. Social and Affordable Housing Legislative in Serbia**

In Serbia, social housing is defined in the Law on Social Housing [54] as "housing of an appropriate standard that is provided with state support to households that for social, economic and other reasons cannot provide housing under market conditions." It has a "housing of an appropriate standard that is provided with state support to households that for social, economic and other reasons cannot provide housing under market conditions." It has a "residual" role [55] which means it is primarily intended for the most socially vulnerable categories, unlike in some developed European countries. Master Plan of Belgrade (MPB) 2021 from 2003 [56] played a key role in introducing and defining the concept of social housing in Serbia, following the example of developed European countries. This Plan identifies socially vulnerable categories of society that need assistance in finding housing and provides certain guidelines for design and construction standards, as well as criteria for determining locations. The Plan has defined a list of 58 locations with a total area of 228.6 ha planned for social housing in Belgrade.

The adoption of the Law on Social Housing in 2009 was followed by the National Social Housing Strategy [57] and The Decree on Standards and Norms for Planning, Design, Construction and Conditions for the Use and Maintenance of Apartments for Social Housing [58]. This is important to mention because in the period from 2001 to 2014, several social housing programs were implemented in Serbia, despite the lack of a defined comprehensive housing system, as well as appropriate technical regulations for planning and designing this type of housing [55,59].

The program of construction of solidarity apartments 2001–2005 was implemented by the Assembly of the City of Belgrade with the public fund for financing the construction of apartments. The project of constructing 2000 socially non-profit apartments in Belgrade started in 2005 by adoption of the Decision on the conditions of sale of 2000 socially nonprofit apartments in Belgrade [60]. Since social housing is seen as a good of public interest, a number of public architectural and urban competitions were announced in cooperation with the Society of Architects of Belgrade. On the other side, public competitions are considered directly related to the public interest, including the widest professional public, and therefore require the highest level of professional and social responsibility. However, in the competitions conducted by the City of Belgrade, the topic of social housing was mostly problematized from the aspect of economy, without considering other specific requirements in that housing category [55].

This is not surprising because, according to Djokic et al. [59], "social housing has been often seen as a measure of the social care system, a tool of poverty reduction, in achieving social justice and ensuring the fundamental human right to housing, but seldom as an instrument of economic development." However, this should not limit the possibility of implementing a strategic framework for improving environmental sustainability in housing with increased resilience and adaptability of housing, the provision of healthy living conditions and a healthy environment, and the reduction of waste from the use of heating and cooling energy, coupled with carbon dioxide emissions, reduction of water and soil pollution, adequate use of materials and waste recycling.

The existing technical regulations for the planning, design and construction of social housing in Serbia do not sufficiently consider specific guidelines in the field of energy optimization and IAQ that would be usable in the development of planning solutions, which is a significant limitation [61]. This is seen in the gap between the recommendations of sustainability in the planned development of the social housing sector in Serbia and their practical application. In addition, "there is a large gap between the inherited experiences of "quantitative" satisfaction of housing needs through mass state housing and "qualitative", long-term goals of sustainable development" [61]. Furthermore, there are no regulations aimed at improving and maintaining indoor air quality. Unlike outdoor air quality, the monitoring and assessing of IAQ are not regulated by legal acts, only guidelines and recommendations related to certain pollutants.

It is also necessary to mention that public buildings constructed within the period between 2010 and 2012 were built in accordance with the special conditions, applying the Law on Encouraging the Construction Industry in Serbia in the Conditions of Economic Crisis [62]. This Law had a fixed term with emphasis on encouraging the development and employment of domestic construction companies and providing liquidity to this sector to strengthen the development and employment of domestic companies engaged in the production of construction materials. The buildings covered by this Law are fully or partially financed from the budget of the local self-government unit, the autonomous province (i.e., the Republic of Serbia) and include schools and kindergartens, hospitals and other health facilities, flats, sport objects, facilities for the purpose of performing cultural activities, highways and other state roads and other objects of public importance. In accordance with the above, the construction of facilities of public interest were completed exclusively by domestic construction companies and with domestic construction materials (70% of the total amount of construction materials and equipment).
