Lighting techniques for good distribution of daylight in a room. – Sparrow Construction Management & Consultancy

Lighting techniques

The primary source of lighting is the sun. Light received by the earth from the sun consists of two parts, direct solar illuminance and sky illuminance.

For the purposes of daylighting design, the only sky illuminance shall be taken as contributing to the illumination of the building interiors during the day

For good distribution of daylight in a room, window height, window width and height of sill should be chosen accordingly. Generally, while taller openings give greater penetrations, broader openings provide better distribution of light. Openings shall be provided with chajjas, louvers, baffles or other shading devices to exclude direct sunlight entering the room, as much as possible.

Two types of lighting techniques are commonly used.

Bilateral Lighting

Windows are the most important and basic element for daylighting. Windows are normally designed according to room size, need and site features to ensure maximum ventilation and lighting. Also, it plays an important role in elevating the aesthetic aspect of the entire building. Based on the size, different window options are available such as pane windows. french windows, top hung windows, Sliding windows etc are commonly used.

Sky Lighting

It Introduces light from above through aperture in the roof. For spaces with demanding visual requirements, brightness control of a skylight is necessary based on the shape of the room and location ‘Nadumuttam’ or open courtyard in traditional Kerala houses is the best example for sky lighting. Nowadays light wells and open courtyards are the two most commonly used sky lighting elements in modern houses as well as in traditional houses. These are either covered by pergolas or glass/acrylic sheets or even kept open in certain cases.