LUCE estratti LUCE 325 _Antico_Cattedrale di Anversa | Page 8

city, i.e. having a visual dialogue and a synergy
with the neighbouring areas. The lighting needs
for pedestrian zones had tight quality
requirements (CCT, CRI, light distribution,
avoidance of glare and intrusion). The character
of the majestic gothic structure, the medieval
urban fabric, and the façades around it required
the creation of a soft, pleasant, and inviting
atmosphere that could prompt local and foreign
visitors to spend time in the immediate
surroundings of the cathedral at night-time.
The historical heritage status precluded the use
of any coloured light, and asked for a high colour
rendering white light to bring-out the natural
hues of the original stone construction.
The profusion of architectural details furthermore
required a close scrutiny, to select the more
important and form-defining ones, ensuring that
none of the emphasized details would upstage
the perception of the entire structure.
Concept
To create the special night-time image of the city.
To emphasize the three-dimensional qualities
of the architecture and details of the cathedral
while respecting the construction materials
and avoiding the visual intrusiveness of the
lighting equipment.
To allow for the discovery of the beauty
and craftsmanship of the architectural details
at the top of the tower.
To allow for a flexible play of intensities, so as
to enable the fine-tuning of luminance balances
and the creation of different scenes and images
according to time of night or annual events.
To create a continuity with the adjacent Grote
Markt square and the streets leading to it.
To enhance the night-time environment around
the cathedral for visitors, boosting the area’s
night-time economy.
To reduce energy consumption and greenhouse
gasses.
Implementation
A minute analysis and an extensive
documentation of the cathedral and its details,
as well as the surrounding buildings and public
spaces, allowed for a precise definition of the
elements to be lit in order to create an enhanced
46
LUCE 325 / SPECIALE CATTEDRALE DI ANVERSA
perception of the three dimensionality of the
whole structure, furthermore enabling the
awareness of exquisite architectural details till
now hidden from sight. It also allowed to make
precise decisions in terms of the location of the
many luminaires intended to be installed on the
cathedral itself, of installation techniques that
would respect the imposed limitations, and of
routing of power and communication wiring.
The Cathedral
The approach was to construct a layered lighting,
starting from the base of the cathedral and
moving upwards:
- Wall-washing the surfaces and accent lighting
the vertical structural elements with in-ground
luminaires. Special care was taken to specify the
light distribution, in order to prevent glare to
pedestrians and cyclists passing by.
- Lighting the first, second and third levels of the
belfry and of the cathedral tower (the lower of
the two) by accent lighting the solid elements of
the window openings with luminaires placed on
the cathedral, close to the base of the openings,
and grazing the stone surfaces. This has been
complemented by a filling layer of diffuse flood
light coming from chosen surrounding roof-tops
and from areas on the transept facing the back
of the towers, thus ensuring no glare or light
intrusion to pedestrians and inhabitants of the
surrounding buildings.
- The fourth, fifth and sixth levels of the belfry
tower, with a complex array of architectural
details, were exclusively treated with luminaires
placed on the cathedral and precisely focused
on the details that required particular accent.
At the fourth level, the gilded clocks on the four
façades of the tower have been enhanced with
very narrow light beams coming from the
surrounding rooftops.
- The vertical walls and openings of the nave,
the transepts and the apse have been treated
with a grazing lighting of the openings’
structures and with an accent lighting of the
vertical structural elements between them.
These also provided the accent lighting on all the
pinnacles ending the structural columns
- A special treatment was given to the buttresses
surrounding the apse.
- The tower above the intersection between
the nave and the transepts got a wash lighting
for its base and an accent lighting for its “onion”
shape dome.
- The roof of the lower tower (above the third
level) received a diffuse wash lighting for its base
and an accent one for its top spire.
- The main roofs of the nave and apse have been
treated with a uniform grazing wash lighting that
also allowed the silhouetted perception of the
carved balustrade surrounding the roof.
The surroundings
A selection of historical facades surrounding
the cathedral has been chosen to be lit in
a similar fashion to the way the historical
facades of the nearby Grote Markt had
previously been lit: grazing light mainly
provided by slim linear luminaires mounted
at the base of the facades (above ground floor
level). Often, the same facades are culminated
by Dutch stepped gables, where an accent
lighting is provided for the side steps.
The pedestrian lighting is provided by a series of
façade-mounted “historical” luminaires identical
to those used in the Grote Markt, with a soft
diffuse distribution located and spaced in such
a way to achieve a relatively uniform coverage
and avoid very dark areas.
The trees in two public spaces adjacent to the
cathedral, traditional seating locations for cafes
and restaurants, are provided with in-ground up
lighting, allowing for a comfortable and intimate
feeling of the trees coverage during spring and
summer time. Finally, five small Madonna and
the infant Jesus sculptures, the Matsijs and the
Appelmans monument have been given an accent
lighting coming from the roofs of a few buildings.
LED lighting has been chosen throughout the
project to ensure an easy control, a long life,
and a high efficacy. 3,000K was the CCT chosen
for the lighting of all stoneworks, as well as
pedestrian and buildings’ facades lighting.
For visual interest, contrast, and better
adaptation to chromatic finishes, the slate roofs
have been lit with 4,000K. In order to ensure
colour uniformity, the specification of the Colour
Rendering characteristics of LEDs is very tight
and restrictive. To ensure perceptive coherence,
similar architectural features have been lit
in the same way.
All of the luminaires have been assigned rational
control groups, so that changes in lighting
of different elements according to different
scenes occurs in an identical manner throughout
the cathedral.
All of the luminaires have been asked to answer
the highest quality in terms of construction
and finishes and minimal dimensions.
Locating the majority of the luminaires on the
cathedral, close to the objects and surfaces to be
lit, allowed for relatively low power and flux,
achieving the wanted levels of luminance and the
precise focusing, and minimizing of wasted light.
The majority of the luminaires installed on
the cathedral are hidden from the sight of those
who admire the cathedral from below.
A total of 780 luminaires have been installed
in the new project, consuming annually
approximately 48 MWh. A total of approximately
13 km of cables were deployed and installed
on the cathedral and its surroundings.