To obtain the Passivhaus Certificate or Passivhaus Standard (PHS), requirements regarding building envelope air tightness must be met: according to the n₅₀ parameter, at a pressure of 50 Pa, air leakage must be below 0.6 air changes per hour (ACH). This condition is verified by following the blower door test protocol and is regulated by the ISO 9972 standard, or UNE-EN-13829. Some construction techniques make it easier to comply with these regulations, and in most cases, construction joints and material joints must be sealed in a complex way, both on façades and roofs and at ground contact points. Performing rigorous quality control of these processes during the construction phase allows achieving a value below 0.6 ACH and obtaining the PHS certification. Yet, the value can increase substantially with the passage of time: as windows and doors are used, opened, or closed; as envelope materials expand; with humidity; etc. This could result in significant energy consumption increases and losing the PHS when selling the house at a later point in time. It is therefore important to carefully supervise the quality of the construction and its execution. In this study, we focused on a house located in Sitges (Barcelona). The envelope air tightness quality was measured during four construction phases, together with the sealing of the joints and service ducts. The blower door test was performed in each phase, and the n₅₀ value obtained decreased each time. The execution costs of each phase were also determined, as were the investment amortisation rates based on the consequent annual energy demand reductions. Air infiltration dropped by 43.81%, with the final n₅₀ value resulting in 0.59 ACH. However, the execution costs—EUR 3827—were high compared to the energy savings made, and the investment amortisation period rose to a 15- to 30-year range. To conclude, these airtightness improvements are necessary in cold continental climates but are not applicable on the Spanish Mediterranean coast.

El mariscal de Belle Isle (1684-1761) construyó el Château Bizy (1741-1743), con voûte à la Roussillon, como también lo hará el Comandante de Espié (1708-1792) en el Hôtel de Espié (1750). Queriendo patentar este sistema para construir cubiertas incombustibles, lo intentó justificar en la Maniere de rendre toutes sortes d'édifices incombustibles (1754). Los intentos para homologarlo en la Académie royale d’architecture (1755) fracasaron, imponiendo sus miembros la notre maniere, cambiando la disposición plana del ladrillo en la calota, a la de canto. La bóveda tabicada tuvo poca fortuna entre los arquitectos ilustrados franceses, pero su utilización será sancionada por los ingenieros militares en la Académie royale des sciences. A parte de las ediciones de la obra de Espié, y mucho antes que en el Cours d'architecture (1777) de Blondel y Patte, la obra será ampliamente difundida por autores de la Orden de la Compañía de Jesús.

Regulatory demands for indoor air renewal in buildings entail high levels of energy consumption. This is the only way to provide minimum indoor air quality (IAQ) and avoid some common lesions and pathologies. In Passivhaus standard (PHS) houses, a heat recovery system is required between the indoor–outdoor air masses of the air renewal system. This configuration substantially reduces energy consumption. In addition, the obligation to reduce envelope air leakage below the n₅₀ value of 0.60 ACH usually allows for a decrease in the energy consumed to less than 15 kWh/m²y in winter, as required by the PHS. It is complex, however, to quantify the energy demands of a building, whether in the project phase or in the operational or use phase. The present study focuses on the application of the PHS in Spanish Mediterranean housing. The aim was to assess whether it is suitable to use heat recovery systems by quantifying the energy savings obtained, execution costs, infiltration air flow, ventilator power usage, and maintenance. To this end, we performed a study on an existing PHS house in Abrera (Barcelona, Spain). It was found that heat recovery systems are always cost-effective in cold climates such as that of Central Europe but are only profitable in Spanish Mediterranean houses when the system costs less than approximately EUR 2500. In this case, the investment is covered over a period of 9.4–12.8 years and over 14–18 years when the equipment costs more than EUR 3000. Annual savings range from EUR 184.44 to 254.33 in Abrera compared to EUR 904.99 to 934.82 in a city like Berlin, that is, a 400–500% increase in savings. Moreover, leakage air energy accounted for 13% to 15% of that of renewal air, −1.348 kWh/m²y and 2.276 kWh/m²y compared to 8.55 kWh/m²y and 17.31 kWh/m²y, respectively. Lastly, recovery system average efficiency or η_t performance—which is usually between 82% and 95%—did not play a relevant role in deciding whether the system should be installed or not.

In the municipality of La Granja d’Escarp, for over thirty years, an important natural cement factory was in operation. In 1876, the Girona family, who were businessmen and bankers from Barcelona, opened the factory with modern industrial facilities. It included kilns, mills, and crushers, alongside warehouses, a small railway for internal transportation of the various materials used, and even a housing area for workers. The neighboring Ebro River allowed distribution by river transport at first. Later, with the use of railways, transport to consumption points was possible. This industrial complex became a center of significant importance in Catalonia in the production of cement, which was used for building hydraulic and civil works. During the first decade of the twentieth century, the factory stopped its activity and the facilities were abandoned. Nowadays, this industrial heritage site is in a state of neglect, without any kind of protection or maintenance. In turn, this has caused the collapse of some buildings in recent times and the loss of historical value of the architectural ensemble. We have carried out initial geomatic research, which has highlighted the constructive properties of the kilns. We have also tested five samples from different buildings using XRD and TGA/DSC, which showed the use of lime mortars in their construction. This is the first study to be carried out at this site, with the aim of showing the historical importance of the ensemble. The goal of the study was to highlight the value of this industrial heritage site and illustrate that it was once a pioneer in the production of natural cement and a driving force for Catalonia.

An unknown aspect of Josep Lluís Sert (Barcelona, 1902–1983) is his deep engagement with Christian spirituality, particularly following his American exile. This perspective is beautifully reflected in his religious-themed projects, among which historiography has highlighted the church of Puerto Ordaz (Venezuela, 1951), the Chapel of St. Botolph (Boston, 1963–1968), and the Carmel de la Paix Chapel (Mazille, 1967–1972), designed, respectively, before, during, and after the Second Vatican Council. Using these three well-known projects as a starting point, our aim is to expand the discussion around this topic to encompass the entirety of Sert’s sacred architecture. The contributions of Sert to the design of modern religious architecture are analyzed in this study, firstly through the distinctive aspects of his architecture, such as its urban scale and interactions between various plastic arts, and secondly through his theological references. This study is based on Sert’s original drawings, as well as specific bibliographic sources and articles from specialized journals. At the same time, it seeks to highlight an aspect of the architect that, despite the significance and brilliance of his designs, has received little attention until now.

This research delves into the influence of St. Augustine on the construction of the Gothic cathedral of Tortosa. The canonical cathedral of Tortosa underwent re-establishment in 1155, which was carried out by Bishop Godfrey who was the abbot of Saint Rufus of Avignon and was governed by Beati Augustini rule. The presence of St. Augustine in the Capitular archives with De Civitate Dei (ACTo-20) from the XII century is examined. This, coupled with a spatial analysis of the liturgical space using laser scanning (TLS), serves to validate the historiographical thesis put forth by Wilhelm Worringer, Erwin Panofsky, and Otto von Simson for understanding the construction of the apse of the Gothic cathedral (1346–1441). This methodology establishes a bijection between patristic and Neoplatonic sources and the interpretation of the liturgical space’s dimensions using statistical systems. This approach addresses the construction of the apse through the incorporation of a heptagon, a geometric figure that is absent in Euclid’s Elementa and Ptolemy’s Almagest. In conclusion, it is determined that both the imagery and metrics employed in the design of a radial heptagonal apse, as well as its cross-section, are influenced by both St. Augustine and the metrics of the Neoplatonics, which remain present in the Chapter Archives.