© 2017 Redfundamentos s.l. All rights reserved. The first necessary operation for the determination of an architecture that is defined as territorial implies the physical definition of a boundary. A frontier whose first consequence is the establishment of an order capable of differentiating between the hostile-out and the safe-in. This boundary allows qualifying a first stage of permanence, granted by the most immediate refuge and yet allows successive diversions from its meaning both in terms of the initial definition of this interior-exterior boundary and the materiality of its formalization. Full confidence in this idea becomes the basis on which, in 1963, Charles Moore and his team (MLTW) build the project for Condominium I in the Sea Ranch, a real example of Sussane Langer's ethnic domains, but also a reflection on the construction of the border that is as Europeanist as American. The challenge of domestic construction is here in the definition of a threshold that, beyond limiting the obvious outdoors, allows the inhabitant to know their location at any time, hierarchizing and specifying itself to become a space with its own identity that can be read in an authentic Californian key.