IJUP08 - Universidade do Porto

Zenithal Illumination – from Alvar Aalto to Álvaro Siza’s work
Faculty of Architecture, University of Porto, Portugal, Mafalda Rangel Campos
This investigation tries to make an approach to the theme of Light Presence in Aalto’s and
Siza’s architecture. It faces daylight as one of the major aspects, which influences their
project’s process, in which light is a geographic variant. Which architectonic forms they
have chosen to interpose between Man and Sun, so that a certain space becomes a library
or a museum?
A previous analysis of their most important creation makes it possible to understand how
often the use of zenithal illumination is associated to public buildings. As a consequence,
this study explores its presence in libraries, museums and exhibition spots. The structure of
this investigation reflects its methodological process. It starts from the conceptual analysis
of light in architecture as a way to clarify fundamental aspects of the theme, progressing
towards the practical analysis of several public buildings. Chapters I and II explain the
conceptual and historical study of the zenithal illumination, tracing a constructive
evolution. Chapter III makes an approach to the trajectory of both architects and the
cultures they are bound to, also including evolution of their work and individual
exploitation of permanent concepts in their legacy. Chapter IV explores an analysis of
selected works, establishing direct and indirect relations between them, in order to
systemize space characters created by the zenithal illumination.
Chapter IV shows that both architects have invented, re-created and re-used different
daylight control systems, mostly using indirect and diffused lighting for libraries and
museums. It was possible to systematize and group buildings according to the use of the
same shape and therefore understand the chronological process the architects have gone
through.
It possible to conclude that the shapes chosen by Aalto and Siza to interpose between Man
and Sun are not only directly connected to the existing daylight conditions. In their
libraries and museums it is visible, that the process of shaping a roof is always a
compromise between the light conditions of the place and the individual formal research
that each architect has been developed.
Fig. 1 Viipuri Library- Reading room - Alvar Aalto
Fig. 2 IT Faculty Library- Main reading Room-Santiago de Compostela - Álvaro Siza
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