317wanders, for example, across the convex exterior of an ar-
chitectural volume, moves around it, but also glides over to
the surfaces of neighbouring buildings that form the contours
of a public square, before continuing onward to the concave
inner side of the delimitation of the square. Within a > space-
body continuum, surfaces establish connections between
concavity and convexity as well as between > inside and
outside. Similarly, the surface of the concave inner side of a
niche leads across to the adjacent wall via the convex exterior
of a framing pillar. On all scales, body and space pass over
into one another through the continuous plastic modelling of
surfaces or by being folded (> folding) into one another.
But surfaces play a role in architecture not just as the
boundary surfaces of bodies and spaces; they also furnish
perception directly with stimuli that correspond to the senses
of touch, sight and smell. Surfaces determine the impression
made by colour and material, while influencing optical and
acoustical reflection behaviour. The sensuous effects of archi-
tecture rest to a large extent on the treatment of its surfaces.
The groping gaze receives haptic impressions that substitute
for those gained through touch; via > synaesthesia, the other
senses come into play as well.
Recognizable on surfaces in particular are the various
characters of the > materiality; the effects of materials on
spatiality are developed there. Special effects that are gener-
ated through the treatment of the surfaces themselves are also
visible here. Strong effects of translucency and light fusion,
conditioned by the respective depth of penetration of the
light, cause surfaces to appear soft; without diffusion, con-
versely, they appear hard. Various types of reflection generate
a glossy sheen, a matte gleam, and other optical transforma-
tions of the light. Through shimmering or iridescent surfaces,
an impression of vibration can be generated that encompasses
the space as a whole. Through the depth of the light that pen-
etrates the surface, coloured glazes and transparent layers of
plaster such as stucco lustro endow a room with additional