9 Vault House is a minimal home located in Villanueva de la Serena, Spain, designed by José María Sánchez García. 

There is a structural asymmetry between the ground floor —defined as a grid of rooms with arched vaults and bearer walls— and the open plan first floor with its pillars and intermediate supports. The project inverts this structural order due to the functional requirements, allowing a new spatial and programmatic arrangement. Two T-beams relieve the space of the need for intermediate supports, permitting the creation of a new open plan ground floor.

The combination of brick arches and concrete beams generates a spatial grid of successive beams and vaults that span a highly complex space. Functional logic dictates the maintenance of the division of the first two rooms —garage and guest room— on the Calle Carrera side. The living room becomes a diaphanous space that opens horizontally onto the interior garden, protected vertically by the structural cross and the six groin vaults. While the floor plan generates a continuous space, these vaulted ceilings create partitions within it.