CB House by Alventosa Morell Arquitectes: A Sustainable Courtyard-Driven Transformation in Sabadell, Spain

Located in the dense urban fabric of Sabadell, Spain, CB House by Alventosa Morell Arquitectes is a compelling example of how a sustainable renovation can overcome spatial and environmental constraints to create a luminous and healthy contemporary home. This 105-square-meter residence reimagines a deteriorated single-facade structure confined by party walls, transforming it into a bioclimatic sanctuary through architectural ingenuity and environmental sensitivity.

A Context of Limitations

The original house sat atypically at the back of a narrow plot, boxed in by three party walls with only one façade facing the street. Built on a 90m² ground-level footprint and flanked by neighboring courtyards and garages, the structure suffered from severe issues: poor lighting, lack of ventilation, capillary moisture, and structural pathologies. Preservation was not viable; regeneration became essential.

Central Courtyard as Climatic Heart

The architectural strategy centered on the relocation and expansion of the existing courtyard into the heart of the home. This newly enlarged central courtyard not only becomes the spatial and social nucleus of the house but also a passive environmental regulator. Covered by a glass roof, the courtyard admits ample natural light, enhances air circulation, and acts as a thermal buffer across seasons.

In winter, the space stores solar energy, benefiting from the thermal inertia of the ceramic walls and concrete slabs. In summer, the same space adapts into a shaded outdoor terrace, enabling the family to enjoy fresh air while remaining shielded from the intense heat.

Bioclimatic Performance and Energy Efficiency

CB House achieves outstanding thermal comfort through passive climate control strategies, maintaining an annual energy demand of just 19 kW/m². The central courtyard functions as a greenhouse, regulating indoor temperatures while minimizing dependence on mechanical systems.

Key bioclimatic strategies include:

• High-performance thermal envelope
• Controlled cross-ventilation
• Use of local biomass-fired ceramic masonry
• Cellulose insulation from sustainable sources
• Extensive use of wood in windows, ceilings, and cladding
• Thermal inertia from thick masonry and concrete

These techniques not only extend the building’s lifespan but drastically reduce its ecological footprint.

Material and Detail Integrity

CB House is a homage to material authenticity and local craftsmanship. Timber and ceramic dominate the interiors, creating a warm, tactile experience. Elements like shelving, exposed beams, and brick detailing preserve a sense of regional identity while aligning with contemporary aesthetics. All materials, including wood from Fusteria Jaume Olivé S.L and ceramics from local bóvila, were sourced or fabricated sustainably.

An Urban Refuge of Light and Calm

Beyond its sustainable credentials, CB House offers a deeply humane living experience. The architecture shields its inhabitants from urban noise and stress, providing a peaceful domestic environment that harmonizes with nature through architecture. The central courtyard—light-filled, breathable, and adaptable—is more than just a design feature; it's the soul of the home, embodying the principles of climate-conscious architecture.

All Photographs are works of Adrià Goula