Social housing to nZEB - Portuguese context

Abstract

In the 80's and 90's, the various Portuguese Governments set the goal of rehousing the majority of the low-income families without a proper house, through a program to build Social Housing. Municipalities assumed the role and developed the solutions to meet the needs. The necessities defined priorities, efforts were directed to quantity rather than quality: 120,000 apartments distributed by 24,500 buildings, in 25 years. Designed in-house or contracted out with a conventional approach and a limited budget, around 500 euros/m 2 . The construction was outsourced and hasty, due to time constraints. Although the construction were common, in technology and design solutions, some architectural prizes, National and International, were given to authorial projects. These became symbols of the progressive Portugal Architectural Heritage and of the success of the Portuguese Social Experience, recognized as architectural points of interest, for tourist and specialists. As time goes by, maintenance falls short and requires critical conservation, tenants demand rehabilitation and renovation, mostly to situations related to the loss of comfort and quality, associated with water damages in the constructive solutions. The research regarded the latest European Union policies, on GHG emissions and energy consumption reductions in new building design, to pursue the nZEB's, "nearly Zero Energy Building(s)" concept. By developing a low-cost building renovation founded on new constructive solutions to actualize the envelopes' response: decreasing maintenance's needs and expenses, increasing user comfort while aiming the reimbursement of the investment period. Based on the "Renovation or Rehabilitation -Decisive Gains (RoR-DG)," (Nuno D. Cortiços) benefits were accounted considering achieved savings minus investment: relying on the system's performance, as rated by the key indicators of "Facilities Maintenance Management Model" (Igal M. Sohet and Sarel Lavy). This approach was applied to measure the impact of the first Eco-Neighborhood, applied to a Lisbon social housing park (Bairro da Boavista, Monsanto). Although the Program's positive achievements, the results show a low impact on efficiency. For the future actions it is advisable an overall thermal reinforcement, follow-up measures, additional financial support, and the tenants' commitment.