• The survey, also direct, of the environment
and the digital format rendering (plans,
sections, elevations);
• Description and dimensions of the
environmental components (windows,
doors, balconies, cornices, false ceilings);
• Description and dimensions of furniture
and movable objects;
• Description and size of the objects/works
of art, and their classification according
to the photosensitivity of the materials;
• Classification of the materials present
for thermo physical, optical, photometric
and colorimetric characteristics;
• Identification of electrical network diagrams,
cables, plugs, wiring and control units,
as well as positioning of emergency lights;
• Identification of the possible presence
of sensors and control systems of the luminous
flux of the artificial lighting fixtures
and their classification;
• Detection of any manual or regulated window
screening systems based on the intensity
of the incoming natural light;
• Data and information on the lighting fixtures
present in the environment for geometry,
dimensions, positioning of the pointing
angles and their optical, colorimetric
and photometric characteristics.
Reference has been made both to historical-
bibliographical studies, useful for understanding
space, place and architectural form, and
to recent sources of international literature,
but above all to field measurements,
to characterize the different materials
and surfaces from an optical, photometric
and colorimetric point of view 1 . Direct
illuminance measurements were carried out
on the lamp body and on the walls. Targeted
research on literature sources and technical
catalogues allowed us to trace the luminous flux,
colour temperature, and photometric curve
of the existing lamps (secondary sources and
optics). There were many measurements made,
and it was not always possible to carry them out
with complete continuity due to the reduced
access possibilities, to which practical difficulties
were sometimes added, often due to weather
conditions non-optimal for the evaluation
of natural light. Some measurements were also
performed on particularly large surfaces, using
traditional detection techniques based on the
use of lux meters, colorimeters, and
measurement point grids adapted to the
dimensions of the spaces and of the different
planes, but based on ad hoc techniques and
solutions that guaranteed repeatability and
sequentiality of the measurement itself in
a short time. The experimental set-up included:
• the definition and preparation of the lighting
grid as reported in UNI EN 12464-1:2011 2 ;
• the characterization of the sky conditions
and the position of the sun at the beginning
of each measurement campaign;
• the identification of the time slots of
environmental use (morning, early afternoon,
evening);
• the illuminance value measurement for each
of the points identified within the room
and the repetition of the measurement
to reduce the average and relative error;
colorimetric measurements for characteristic
surfaces/furnishings, and their conversion
into RGB or HSV format, depending on the
type of analysis and simulation conducted.
The measurement protocol was drawn up
taking into account the requirements of the
UNI 11630:2016 standard 3 . We used measuring
instruments that comply with the requirements
of the current legislation (CIE S023/E:2013 4
and UNI/CEN TS 16163:2014 5 ). The experimental
set up was implemented in two steps: a phase
of dimensional analysis and preparation
of the grid, and a phase of actual measurement
campaign that was carried out during the
opening hours and consequently of use of the
library. This fact implied the condition, for most
of the measurements, of a mixture of natural
and artificial light, because the measurements
we made were relatively invasive, and it was
thus possible to access the library during its use.
Although the movements of the occupants were
restrained, it made it difficult for us to measure
some specific points, especially those near
the worktops and the shelves containing books
for consultation. The crucial phases of the
measurement campaign were supported
by the following analyses:
• The analysis of climatic data of sky conditions
before and during measurements, provided
by local meteorological sources (LAMMA
CNR IBIMET of Florence);
• The assessment of the amount of solar
radiation entering from a thermal and radiative
point of view, calculated from the hourly
climate data provided by the LAMMA CNR IBIMET
centre in Florence;
• The definition of the number of measurements
and of the series or repetitions as well as the
trend of the field measurement for each series;
• The identification and definition of the
boundary conditions (e.g. light coming
from adjacent rooms, lighting fixtures not
functioning at the time of the measurement
campaign, etc.);
• The identification of the surfaces characterizing
the environment by type, shape,
thermo-physical and colorimetric features;
• The full implementation and stabilisation
of instruments by means of sequential tests 1 ;
• The detection of the colorimetric coordinates
of the surfaces characterizing the environment
with CL-200A colorimeter, Konica Minolta,
and their conversion in RGB format with c
olour coding of the CIE-1931 and CIELAB
Colorimetric diagram.
Another type of field survey concerned
the definition of the physical nature, in terms
of roughness and surface treatments, of the
different existing surfaces, coatings, decorations,
and materials. The colour, the surface treatment,
the relative roughness, and the state of
preservation were verified during the survey
phase. A dedicated photographic survey on place
was also conducted. The transparent surfaces,
as well as the shielding systems, were defined
from a thermo-physical and an optical point
of view. The transparency coefficient
of the windows was evaluated in function
of the vertical illuminance measurements
in the presence of defined natural light and sky
conditions for all openings. For this purpose,
the illuminance values on the vertical plane
were measured, taken outside the glass and
in some cases between the glass and the curtain
Figura 6. Punti della griglia per misure
di illuminamento / Grid points for illuminance
measurements
and between the curtain and the internal
environment, and then finally compared with
the data calculated according to the hourly angle
of height and azimuth of the sun and, therefore,
to the hourly variation of the angle of incidence
of solar radiation.
Brief history and connotative cultural aspects
We carried out an in-depth study concerning
the historical, architectural, and cultural aspects
of the building, of the different environments,
and of the context, using the existing paper-
based sources in the archives as well as texts
and literature references 6 . This study related
to architectural and geometric surveys allowed
us to evaluate the state of conservation,
the thermo-physical and optical photometric
characteristics, and the degradation of the
materials (mainly wood and paper) and of the
existing objects, but also the transformation
of spaces and functions throughout history.
The architectural survey, compared with the
few geometrical data made available by the
technical offices, allowed the construction
of a solid model of the environment, of its
own the elements and components, as well
as of the existing lighting fixtures.
The reports and information on the
transformation, adaptation, and modification
processes of the entire building and its facilities
were not many, and not even easily traceable:
following are the salient results 6 . Definitely,
when the destination of use changed the entire
building/system underwent major retrofitting
and building refurbishment interventions,
in compliance with safety, fire, and seismic
regulations. The study of the building’s history
enabled us to reconstruct the main stages
of adaptation and transformation, as well as to
investigate and reconstruct the most significant
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