Sandstone – Marés was used in both the façade and the vertical load-bearing structure of the new Positive Energy Building developed by the public housing provider IBAVI. Employed as load-bearing walls, the locally sourced sandstone contributes to the building’s structural stability while reinforcing its architectural integration with the local context. Its thermal mass and breathability support indoor comfort and passive climate regulation, reducing overheating and energy demand, while the durability of the material ensures long-term performance with low maintenance requirements. This solution ensured high dimensional stability, mechanical strength, and reliable seismic performance, while enabling precise prefabrication and fast, efficient on-site assembly of both load-bearing and enclosing components.