a residence, an office or a factory... the need may be to read a book,
operate a piece of machinery, or whatever. If it is possible for daylight to
provide this, then we expect it to do so.
- The natural appearance of a space, where the overall experience, the
objects and surfaces, are modelled in daylight together with the addition
of sunlight at certain times of day. - The cyclical change from morning to evening, changes which are
varied still further with the weather and the season of the year. Man has
an innate desire for variety and change in his environment, and changes
in the appearance of a space from time to time provide this. - The orientation which comes with the knowledge of a person’s
whereabouts in relation to the outside world. In a totally artificial
environment, a person has difficulty in finding his way inside a building,
a problem which was evident in some of the early artificially lit shopping
centres, where people became disoriented, having problems in finding
their way around the building. - The experience of the world beyond the building, by the view to the
outside, whilst this is associated with the factor of orientation, it has the
added aspect of content... which can be of open countryside, trees and
landscape, but more often than not of other buildings and street patterns.
What is important is not only the content but also the experience of
something at a distance as a rest centre for the eye. Daylight is clearly
crucial. - The experience of natural colour; for whilst the physical colour of our
world as experienced in daylight changes from morning to night, the
changes are a part of our experience; we compensate automatically, a
white wall appears a white wall even if in the evening it may be warmer,
or is coloured by sunlight, or altered by cloud formations... it is the
colour we regard as natural. - Although perhaps not essential, it is a part of the experience of the
natural world that we should be able to receive natural ventilation, by
opening windows. This is a part of the human desire for control of his
environment, whether this be the light on his work, or the air that he
breathes.
On the whole architects had not submitted easily to the tendency
towards the totally artificial environment leading inevitably toward air-
conditioning in larger projects; but tended to be overruled by engineers;
however research work carried out in Britain by Prof. Hopkinson at the
Building Research Station in the 1950s developed the concept of PSALI
or Permanent Supplementary Artificial Lighting for Interiors^5.
The concept behind this research was that provided daylight at the side
of the room closest to the window was adequate, the fall-off of light
furthest from the window could be supplemented by electric sources.
This provided for the historic advantages of daylight listed earlier, most
particularly in providing the impression that the whole room was daylit,
although it was not, permitting the concept of the ‘well lit room’. Whilst
this did not have the immediate effect of reinstating daylight as a primary
source it was left to other outside influences to reinforce the architect’s
renewed interest in the subject.
The outside influences were to some extent political, the sharp increase
in oil prices and the fuel crisis, the gradual realization that the fossil fuels
6 Daylighting: Natural Light in Architecture
(^5) Paper by Ralph Hopkinson and James Longmore. PSALI. 1959