The office building of the RENSON Company is located in Waregem, in Belgium. The RENSON Company produces natural air ventilation products and solar shadings systems with fixed or moveable lamellas.
The building has been designed by the architect Jo Crépain.

This building has won the Energy Award 2003 (Belgian reward), price decreed by the Royal Federation of the Belgian architect company.
The RENSON building is interesting on several points of view; this sustainable building is the window of the company products (solar shading and natural ventilation products).

From the beginning of the project, it has been decided to avoid air-conditioning system by favouring the natural ventilation and lowering solar heat gains by the use of movable solar aerofoil blades.
The natural ventilation system has been studied from the beginning of the project and, as there is no false-ceiling, a large part of the building thermal mass is accessible. The summer overheating risks are thus reduced.
The south-west façade is totally glazed and has no particular solar shading system, except a horizontal overhang.
The south-East façade is protected by movable louvres of ellipsoidal shape made in anodic aluminium. These louvres of Icarus IC300 and Icarus IC 360 type, sold by the company, are grouped in 3-element blocks that are manually ordered by the office occupants.
The louvre inclination can change, in order to regulate the daylight and solar penetration into the room.
Two office rooms have been modelled and analysed under artificial sky, in order to characterise the light penetration and to compare the results with in-site measurements. The scale model and in-site results are close to each other.
These measurements show that the aluminium louvres installed on the south-east façade reflect the light deeply into the room, when placed horizontally.

When the louvres are sloped from 0° to 45°, they play more a rule of light or sun protection.

The louvres are organised in frames of 2m high and 3.3m width. Each frame contains 6 superimposed elements. The frames are organised by sectors, each of them including 3 frames that are interdependent for the louvres rotation command.
The louvre rotation is thus made by sectors (on the whole 433) thanks to engines (on the whole 748), that are ordered by a central unit.
The louvre control is a function of:
- The sun position (date and time) ;
- The louvre location on the façade (orientation et height) ;
- Information collected by the meteorological sensors located on the roof (wind, horizontal illuminance, rain and temperature).

The louvres are tilted according to these parameters and make function either of shading (from 0° to 60°) or of reflectors, in order to increase the luminous penetration (110°), when there is no direct sun.

For each sector, the sun height and solar mask have been calculated, as a function of the time, and it is from this calculation that the louvres slope is determined. For the shading function, the louvres are oriented perpendicularly to the sun. As the rotating movement is only possible by 10° step, the louvre will be perpendicular to the sun rays, with 5° accuracy.

Under cloudy sky, the daylight factor values are strongly dependent on the louvres slope. When the louvre slope is equal to 110°, the daylight factor increases by 33% compared to the value obtained with a 90° slope and by 100% compared to the value obtained with a 0° slope.

The luminous direct transmittance of the louvre is about 70%. This value is constant as the louvre stays perpendicular to the sun.

The MAC's, the contempory arts museum of the French community of Belgium, conceived by the architect Pierre Hebbelinck, is a renovation project made in the ruins of a factory site. This ruin, the old coal mining of Grand Hornu, Belgian equivalent of the Royal Saltworks of Arc and Senans of C.N. Ledoux, is of neo-classic style.

The project consisted of the renovation of a building named " the house of the engineers " and the building of two new rooms called the "bridge" room and the "square" room.

The architects and the project owner wished to favour the daylighting penetration while providing a great protection to the works of art. This protection is again the ultraviolet rays and against housebreaking.
The four rooms are placed one behind each other and have different orientations. They all were studied under artificial sky (mirror box) and artificial sun in order to choose the best daylighting solution according to the needs of each room, under their different constrains.
The architects decided to treat differently the showrooms and the connecting spaces; the showrooms are introverted and do not have direct view to the outside while the connecting spaces establish the link between the museum and the outside. This link is made by lateral view windows that allow the visitor to locate himself in the site.

The artificial lighting has also been studied very accurately in order to make it the more complementary as possible to the daylighting; the luminaires are hidden and the walls colour has been studied in order to make the natural and artificial light the more uniform as possible.
The two first rooms, localised in the " house of the engineers ", have a listed south oriented façade. The direct daylighting supply is very high and it was impossible to modify the façade. The architect has chosen to build a second skin, set back from the existing façade and made up of a translucent glazing highly diffusing, that stops any direct radiation that could come in the room.

The third room, called the "bridge" room, is lighted by two longitudinal skylights that are only broken by a structural beam. The daylighting come thus into the room by the roof and is distributed by reflections on the vertical walls.
The last room, called the "square" room, is lighted by north oriented rectangular sheds.
The on/off electric lighting schedule has been established according to the seasons. That allows consumptions reduction during mid-season and summer.

MAC's web site: www.mac-s.be