Social housing constitutes a partial response to the demand for affordable housing. In Europe, there are different forms of social housing, which are distinguishable based on whether they employ a universal or residual approach. The latter is employed by Italian initiatives for social residential construction, the financial instrument of which is the Investment Fund for Housing, a closed-end fund managed by CDP (Cassa Depositi e Prestiti) Investment, which provides public–private partnerships. The main obstacle to the supply of low-cost houses is the high cost of building areas or, in other words, the high urban land rent. The value of building areas is particularly high in urban areas and in widespread settlement areas, for instance, in Northeastern Italy. The main objective of this paper is to identify the trade-off between urban land rent and housing affordability in a social housing intervention in Pordenone (Northeastern Italy). Four different scenarios are developed, the variables of which are: Cost of the area (urban rent), cost of construction works (quality of the buildings), and household income distribution. The results show that achieving the economic and social objectives of a social housing investment simultaneously is not possible in any of the scenarios evaluated. To allow the social groups most in need to access affordable housing would require a reduction of approximately 30% of the estimated cost of a building area.

Historic buildings are still excluded from the scope of regulatory framework concerning energy efficiency and environmental sustainability since European Directive 2002/91/EC and its following recast. Anyway, it is possible to provide renewable energy source systems in valuable historic buildings according to existing plants characters and possibly controlling complex safety mandatory framework requirements. A case study is presented in order to underline a development of sea hydrothermal energy use in high-value historic building heritage.