165ambivalence between concealment and revelation generates a
special tension between inside and outside. Various types of
transition express the influence of exterior on interior and vice
versa. Robert Venturi (1966), for example, has cited variants
of a double shell, the first of which follows interior conditions,
the second external ones. The outer shell itself, in turn, may
be given a concave shape, thereby delimiting an inside within
external space (> concavity). Fundamentally, gradations be-
tween inside and outside are possible through which the ex-
teriors of various buildings are combined to form an external
interior space, for example a public square, while conversely,
an exterior space may be carved from the interior of a build-
ing, i.e. > courtyard. Gradations from interior to exterior can
be extended in both directions by means of > inversion and
incorporation.
In detail, architecture organizes the relationship between
inside and outside not only by furnishing buildings with
screenings of contrasting character with various > open-
ings for > ingress and exit or > views into and out of build-
ings, but also through detailed elaboration of > thresholds,
filters and > intermediate spaces with the objective of es-
tablishing differentiated > accessibility. Articulated by means
of gradually modulated illumination, > materiality and at-
mosphere are nuanced transitions (> introduction). Inte-
rior and external character may be superimposed in such a
way that inner and outer are experienced in relative terms.
The multifarious ways through which interior-exterior re-
lationships can be shaped in architecture is reflected in the
characterizations of many other architectural concepts.
In a highly general sense, the interior stands for privacy,
possession and in-gathering, the exterior for the public sphere,
availability and dispersal. Whereas the contrast between secu-
rity and intimacy within and sense of lostness, foreignness or
danger without is at times experienced in ambivalent ways.
To be bounded within an interior can be experienced as con-
striction or confinement in contrast with the liberating ex-