The project starts from the need to merge two adjoining houses.
These are two urban plots located in one of the expansion areas of the city of Terrassa from the late 19th century and early 20th century. The plots have a nearly rectangular geometry, except for the back plot lintel, which is inclined, and are oriented to the southeast along the long axis.
The resulting dwelling explores the potential of unifying the two houses through the shared party wall. On the other hand, the exterior garden space (interior island courtyard) is opened up and conditioned. By connecting the different spaces of the dwelling through new passages in this shared party wall, the housing scheme shifts from a linear layout to an indeterminate matrix of spaces, allowing for multiple housing configurations.
The dwelling consists of a ground floor, first floor, and attic.
The project proposes cladding systems with walls made of compacted earth blocks. Special attention has been paid to the thermal envelope solution to minimize energy demand, both in the thermal insulation of the roofs and the facades with the highest losses, providing a shading system to regulate solar gain and prevent overheating and discomfort.
Efforts have been made to minimize the environmental impact of the proposal, both in terms of constructive solutions and execution processes during the construction. Bioclimatic strategies are proposed, such as solar capture on the south-facing façade, chimney-effect ventilation through the central core, the use of thermal inertia, hygroscopic control of ambient humidity, and natural lighting, to reduce energy consumption and improve comfort and health.
Thermal inertia and the ability to regulate ambient humidity in the existing walls are optimized with the introduction of compacted earth blocks (BTC) as the star material of the proposal. Thermal loss areas, such as the roof, façades, and the floor in contact with the ground, are insulated.
The core piece is designed as an element for ventilation and lighting through a system of skylights on the roof and a ventilated walkway on the first floor (P1). In this way, the environmental conditions of the central part of the house, which in this traditional typology are often dark and poorly ventilated, are improved. The central core intersects with the roof through two motorized windows that guarantee natural lighting and solar capture, as well as cross-ventilation of all the spaces in the dwelling. The new core is where the different bathroom devices are located, differentiated according to their use.
The house typology imposes purely structural restrictions and offers a distribution in aggregation that denies the access and service cores environmental qualities, such as ventilation or lighting. By adding two adjacent houses, the expansion of this bay allows us to reverse these features and transform these central elements into drivers of environmental qualities. Thus, we turn the main shortcoming of the pre-existence into the crucial element of the proposal.
The cladding of the façades, as well as the roof insulation, ensure thermal continuity that reduces renewable energy consumption by 60% compared to the limit set by the CTE. The BTC provides thermal inertia (as ceramic brick walls would), but unlike ceramics, earth also provides hygroscopic control. This ability to control indoor humidity represents an “extra” (and unique) comfort feature.