Design solutions for Daylighting

Rising towards the sky, the buildings glow in the night like great luminaries, each of their openings reflecting the activities they house with a more or less bright and colorful glow.

During the day, on the other hand, the direction of the sun's rays is reversed, and these buildings must, depending on the situation, either collect the precious rays needed to light their interiors, or protect themselves from the sun's aggressive rays.

This duality clearly expresses the complexity of a building envelope, its ability to best control daylight to satisfy the needs of users, i.e. :

• improve people's well-being, health and productivity ;

• reduce energy consumption linked to the use of artificial lighting;

• reduce building ventilation and air-conditioning loads.

Beyond these issues, the envelope and its openings are the most obvious expression of the architect's intentions, and "qualify" the architecture like a garment that distinguishes its wearer.

"The history of modern architecture is a story of windows.

Le Corbusier

This document reviews the various factors to be taken into consideration when optimizing daylighting inside buildings.

It begins by presenting the issues associated with building typology and the external environment, and then focuses on façade and roof openings. The question of solar protection is then addressed, with emphasis on the combined treatment of light and overheating issues.

Finally, the characteristics of some specific daylight control devices are briefly presented.

Readers may wish to refer to the previous article [C 3 315] and its documentation to supplement the information presented here.