lightscape[s]
illumination study for the Heysel area, Brussels Belgium

Completion of the study: 1999

realised by:
LAb[au], laboratory for architecture and urbanism:
Manuel Abendroth, Jérôme Decock, Naziha Mestaoui
in collaboration with: Kim Pecheur Pieter Desmedt Jans

Commissioned by: Electrabel/Sibelgaz, Belgium elecrticity producer and distributer

Location: Heizel plateau, Brussels / Belgium
Title of the study: Light_scape(s), displacement maps
location: Heizel plateau, Brussels
Prizes: 'Tech-art prize', Vlaams Ingenieurs Kamer 2000
special thanks: Patrice Neirinckx, AVA architects

Light_Scape(s) is the title of a study envisioning the illumination of the Brussels urban space called the Heizel plateau, commissioned by the Belgian electricity company, Electrabel-Sibelgaz. The Heizel plateau in Brussels is equipped with building facilities for all kinds of large scale events. World exhibitions took place here in the years 1935 and 1958 and, today, it accommodates trade fairs, football games and congress infrastructures. Unfortunately, the urban qualities of the site utterly fail to do justice to its size, the number of visitors it attracts and its historic importance. The Atomium is the sole construction which stands out as a landmark among the conglomeration of individual buildings, being large-scale sites such as the stadium and trade-fair halls, and the infrastructure with its roads,

interconnected pathways and parking lots. The light study was an attempt to reinvest the exceptional character of this urban space by means of an illumination plan. Light study Light_Scape(s) combines a structural urban-planning (light_topography) with a temporal one (light_urbanism) by means of a specifically developed tool for light displays, called displacement maps. The potential of light as a structural and spatial as well as temporal and interactive device is investigated. The relationship of specific light parameters (intensity, colour) to the relative aspects of urban planning (topography, flux, infrastructure) and to temporal aspects (programmes, activities) is determined by the various light configurations, i.e. by the light-scape(s).

1st stage: Development of a software tool displacement maps The lack of tools to display and verify hypotheses regarding lighting on an urban scale led to the development of a custom-made computer program displaying light in the form of a mesh grid overlayed on the urban context. Each vertex (point) of the mesh is related to the light intensity value on a specific spot displaying a global topographic view rather than a simulation of illuminated areas. Due to this abstraction of light to statistical data, the software includes dynamic functions opening the possibility of working in real-time with light as an immaterial and dynamic (variable) matter which, like a process, evolves in space and time in relation to the location in which it is embedded. The function, or rather the tool, for the display and planning of light, is designated by 'displacement maps'.

2nd stage: Light topography Light structures the space in order to create a light topography achieved by the variations of the intensity and colour illumination: points, lines, surfaces and interfaces. The illumination of points acts as the setting for single constructions: lines are employed for infrastructures, surfaces characterising diffe-rent programmatic entities and interfaces mark out areas connecting the Heizel plateau to the surrounding area. This layout of independent programmatic entities are subjected to fine differences in illumination in accordance with their own temporal and spatial logic, thus resulting - in their totality - in a continuously contrasting environment. The variations

of the light scenarios emphasize or blot out the different architectural entities. The interplay of the different entities, in combination with the temporal factors, results in dynamic light_scape(s). In the superordinate light plan, light becomes a dynamic substance envisioning the development of light scenarios varying in time and being in direct relation to the given structures, activities, events, individual uses and interactions of the area.

3rd stage: Light_urbanism articulates light as a temporal device and combines fixed lighting installations with variable and reactive ones. The fixed installations include the static options of 'light on' and 'light off'. Variable illumination is related to the activity the buildings are genera-ting and reactive light interventions depend on the individual use of the space. In line with their corresponding topographical counterparts, fixed light installations relate to intermittent structures (light_topography). Variable installations, in contrast, are used for activating surfaces, and reactive installations correspond to the interface status; the variable inputs of the locations are converted into light processes. At the minimum level of activity, for example, the Heizel stadium is surrounded by a medium-intensive luminous ribbon. At the maximum level of activity, on the contrary, it is enclosed within a scenario of white light of high intensity. Because white light is a synthesis of all the colours, it is used on the urban scale in connection with density, event and activity. Here the relationship of specific light para-meters (intensity, color...) to the relative aspects of urban planning (topography, flux, infrastructure...) and to temporal aspects (programmes, activities...) can therefore be determined by the various, evolving light configurations, light-scape(s). These Light_scapes are data-driven configurations based on the programming of light in space and in time and constitute a new method of a pragmatic and operational position of the architect who refuses to fix the structure in a given state. By means of this light analysis and method of simulation, light in public areas can be deployed not just as a simple illumination device but as a polysemic medium which adds a cultural dimension to the urban context. The architect thus becomes a designer of a generated and initiated process: an architecture of light on the scale of the city.

Examples:

Interactive:

The intervention of Parking C, which can host up to 10 000 cars, treats the main access as a large scale landscape intervention. The exis-ting concrete blocks are coated with a phosphorescent paint. During daytime it taints the landscape in its greenish colour which turns into a luminous landscape at night reflecting the environmental parameters by the intensity and the localization of emitted light. As such it turns into a reactive surface, where for example a car passing by produces a temporary trace of its path.

Varianble:

At the minimum level of activity, the stadium is illuminated by coloured light and at maximum level by white light. The minimum illumination is constituted by a red luminous scrolling ribbon, medium illumination by the colour illuminated tribunes below and maximum illumination with the same light devices augmented by four high intensity light pots. Where white light is the synthesis of all colours, the project transposes the RGB-code of light to the urban scale interrelated to density, event and activity.