Both dreams and stones run parallel in their participation with the architecture of the home.
Taking the home as a theatre - that is, as an encompassing stutter, principally informing the stutters at play within it - Akhilleus must too approach what makes the home a peculiar theatre: its determination by architecture - architecture as an oblidging force. And Akhilleus, an erector of signs, enters into - in the dream he relates - what it is to be a constructor of homes.
The short answer: to be a constructor of homes is, then, to enter into the architecture of obligation, to step into green rooms.
The obligation could be summed up that the house is oblidged to follow its architectural design - the sides of the roof meeting at the particular pitch - and the inhabitants too oblidged to follow this architecture insofar as certain rooms must be gone through in a certain succession, the first floor before the upper level.
But, the oblidgation is administered and followed in the pattern of a network. House and inhabitant oblidge each other in a constantly shifting lay-out. And this is what could be called the 'architecture of obligation'.
This interaction does not occur solely in the phenomenological experience of the inhabitant, but is too an interaction between an ideal experience and a material experience, summed up in the opening sentence regarding dreams and stones.
To inhabit is to be always in the process of constructing the home, at least in the sphere of the ideal. And this is the process of the inhabitant oblidging the home to meet certain patterns, for a room to be a certain kind of rectangle.
The material of the home, the 'stones' as it were, oblidges the inhabitant into certain patterns of inhabitation, for a room to be walked in a certain kind of stride.
The influence of both of these forces of oblidgation is synthesized in the overarching 'architecture of obligation'. As both the ideal and the material come to be as a result of these internecine oblidgations, both are dependent for their existence on the network made possible by the architectural home. The obligations are both mutually destructive as well as constructive in their service to the autonomy of the network.
The conceptual meeting place of dreams and stones is in the green room. The green room, then, could be noted as the spatialization of the networked interaction between these obligations.
Harbison places the green room in a green dream of the garden when he asserts that "every garden is a replica" - made as much as it makes in a network between greens and gardener. The green garden is proof that this networked oblidgation does not stop in the green room - the green room being only the room where the ideal and material meet in the architectural home. The architecture of nature - its lines and lymnes - meet other patterns of oblidgation.