An ecological mortar is designed from industrial sub-products, with the objective of utilizing both the slag residues, generated during steel manufacturing processes, and the waste from Polyurethane Foam (PF) panels, generated during refrigerator chamber manufacturing processes. The ecological mortar design involves the dosing of Electric Arc Furnace (EAF) slag, together with finely ground Polyurethane Foam, cement, and additives. An energy efficient prefabricated block is designed with the mortar, for use in construction, and its energy performance is assessed as a material inserted within the envelope of a service sector (hospital) building, either as an exterior skin, or as an enclosing component within the façade interior. The main contribution of this research is the characterization of the thermo-physical and mechanical properties of a new prefabricated panel made with recycled materials. The full characterization of the properties of these new materials is presented and discussed. The new prefabricated panel demonstrates adequate thermo-mechanical characteristics as a substitute for traditional materials, while improving the sustainability of the building. As a secondary objective, the energy behaviour of the new panels when integrated in a real building is presented by means of a case study simulation. The use of computational thermal simulation confirmed that the properties of the prefabricated block influenced the annual thermal demand of the building for heating and cooling. Improvements to the thermal inertia of the building envelope were also confirmed with the inclusion of PF waste, giving the mortar an energy performance that was similar to conventional materials, in such a way that its use in façade construction may be validated, in addition to its environmental benefits, due to it having been manufactured with critical recycled industrial waste such as EAF slag and PF, thereby contributing to both the circular economy and sustainable development.

It is increasingly recognised that the energy renovation of the existing building stock will be determinant for achieving 2030 and 2050 decarbonisation targets in Europe. As operational energy is being dramatically reduced through regulatory efforts and funding from the European Union, the relevance of the environmental performance of these interventions becomes higher, namely regarding embodied energy and carbon emissions associated with the materials that compose the renovation solutions. Although some studies address these impacts in buildings, the range of studies focusing on the neighbourhood scale is limited. This article presents a methodological framework combining a life cycle cost assessment (LCC) and a life cycle assessment (LCA). The purpose is to assess the relevance of embodied energy and carbon emissions on the cost-effectiveness of building renovation solutions towards nZEB at the neighbourhood scale by comparing an operational energy approach and a whole life cycle approach in a case study of a social housing neighbourhood in Braga, Portugal. The results suggest an increase in indicators values demonstrating a negative impact on the achievable reduction of both energy and emissions when the whole life cycle approach is considered, which can constitute a critical point for policy formulation in the decarbonisation of the built environment.

Vernacular architecture embodies a lasting connection between communities, climates, and topographic landscapes, providing basic shelter needs for centuries. Adopting Montesinho Natural Park as a case study, this paper explores the essence of vernacular architecture, highlighting its adaptation and dynamic relationships with local climates, geographical features, and scarce resources. This paper firstly provides a quantitative characterisation of residential vernacular building typologies in several villages of the park based on field-collected data, using photography and videography for data reliability. The building typologies were then categorised according to their prominent architectural features, prioritising the access to the upper floor and door’s relative location and their integration within the landscape’s topography. The collected data were analysed by averaging each typology percentage across the villages and calculating dependency probabilities between each typology and the villages, aiming to identify the most frequent typologies and their dependency relationships with villages. This paper’s outcome entails the Protruding Staircase typology as the most common typology in the selected villages. Despite modern interventions, traditional features endure, emphasising practicality and resource efficiency. Among them, several bioclimatic strategies were identified and analysed qualitatively based on their potential contribution to energy efficiency and savings, highlighting their relationships with the local context and the typologies presented. The findings are important in supporting decision-making related to vernacular heritage in Northeastern Portugal. The bioclimatic construction strategies identified may be used as preliminary references to incorporate into rehabilitation projects and sustainable architecture practices, enhancing inhabitants’ thermal comfort and living conditions.

Present waste management policies aim to reduce waste environmental impacts and improve resources’ efficiency. The use of waste and recycled materials to develop green construction materials are attracting researchers worldwide to develop new solutions addressed to increase the sustainability of buildings. This work presents a study of a new recycled mortar panel from the point of view of its contribution to the sustainability of buildings. Materials from industrial waste, as rigid polyurethane foam and electric arc furnace slags, are used as an additive of prefabricated mortar panels. The new proposed panels must have good thermal behavior with respect to the heat transfer interactions with the outside temperature and relative humidity, when compared to traditional brick or concrete. A test building with two kinds of representative uses, which are both residential and tertiary, and located in three cities of Spain with different climates, will be energy simulated in order to assess the thermal behavior of new construction or refurbished opaque ventilated façades with the new mortar panel. The thermal behavior of the new mortar panels would be studied by means of two energy assessments: (i) the evaluation of the influence of the new mortar panel in the energy demand of the whole building when compared to traditional materials, and (ii) the detailed analysis of the transient inner surface temperature of the space walls when using the new mortar panel. Based on the results obtained from the energy simulations performed, it follows that the thermal behavior of the mortar panel is, at least, equivalent to those of the other two materials, and even better in some aspects.