309horizontal plane offers the required stability of the ground
(> floor). Together, they form the right angle that is preferred
as a norm. In contrast to the slanting plane or ramp as a
gradual transition between levels, the stairs form discrete,
connected, intermediate levels that decompose a vertical gap
into practicable steps. At the same time, as a composite of the
positioning and stratification, they represent basic elements of
tectonics. Proportion and rhythm of the form through
which a staircase is ascended are essential for our gait; with
some persistence, we favour consistency of movement in as-
cending and descending.
An important precondition for a practicable staircase is
a consistent relationship between the height and depth of the
steps (riser and tread), and with a ramp, a uniform incline.
Perpetual variation would hinder a rhythmically uniform
pace; losing our step, we would falter and stumble. Through
prior experiences with staircases, we have generally internal-
ized a schema of ascent that allows us to arrive at the gait
that allows us to best negotiate a given set of stairs. More
than other architectural elements, a staircase prescribes the
movement that takes place upon it, guiding it: at the start, it
receives us, confronting us with a series of distorted or spiral-
ling steps, subdivides stages of ascent through landings, steer-
ing us by means of curving or twisting flights, reversing our
trajectory of movement through changes of direction, and not
least of all, shaping the appropriate form of use through the
gradient of ascent and the formation of steps and railing/ban-
ister. Idiosyncratic arrangement of stairs, i.e. those found in
Baroque staircases, induce a characteristic > figure of move-
ment during ascent.
- Stairs are not only access elements for the building as a
whole, but also generally demand their own staircases. These
either consist of stairwells or > space containing walls, or they
occupy major portions of buildings as representative stair-
cases, and seem to want to ‘appropriate everything, to con-
quer the entire interior of the building,’ as Michel Tournier