What is the world without light? There are various sources of light but natural sunlight is no doubt the most preferred. Daylighting is the process of illuminating a space with natural sunlight. True colors of materials can be seen accurately in sunlight. The living room, kitchen, and other areas where most of the daytime is spent have a need for daylight. Lack of daylight is said to be the reason for Seasonal Affected Disorder during certain climatic conditions. 

Daylight is the most abundant source of light available and it is up to us to make the best use of this natural resource. Some of the prominent ways are-

1. Windows
2. Doors
3. Rooflight or Skylight
4. Glass Blocks
5. Mirrors

Some of the more specific methods of daylighting are:

1. Rooflights/Skylights
2. Glass Blocks
3. Prismatic Glazing
4. Light Shelves
5. Light Pipes
6. Solar Shading
7. Externam Shading

1. Windows

• Windows are the openings provided at the sides of rooms, on the walls.
• They not only bring in daylight into the interiors, but also become a portal to the exterior, showing the views.
• Windows may be horizontal or vertical, with different spans.
• Clerestory windows are placed high upon the wall, used to bring light deep into the interiors and to illuminate the roof structure.
• It is important to provide shading elements for any type of window used.

2. Doors

• Doors need not be a solid block of opaque material.
• Transparent glass doors are a good way of bringing light from the exterior to the interior.
• French doors are a great example. They allow light to travel beyond and through spaces.

3. Rooflights or skylights

• Originating from the roman atrium, rooflights or skylights are great sources of daylight from above.
• These openings can be of different shapes and sizes.
• They effectively let light penetrate into the deep areas of the buildings.
• They come with certain disadvantages. Some of them are:

        a. The light will be projected in the shape of the skylight

        b. The light entering will be harsh, casting sharp shadows

        c. Dust and dirt might be shown in clear skylights.

• These problems can be solved by using bronze tinted or frosted skylights.

• They distribute light more evenly and minimize maintenance.

4. Glass blocks

• Also known as glass bricks, these materials turn walls into windows.
• They come with variations. For example- clear, patterned, frosted, curved, colored, etc.
• This allows for different degrees of light transference and privacy.
• This is an effective method to illuminate rooms with no direct lighting by borrowing light from adjacent rooms with light sources.
• Illuminating the wall opposite to the glass wall results in the illusion that the glass blocks are illuminated.

5. Mirrors

• Mirrors are a great tool to enhance daylight in a room.
• By placing windows on one side and mirrors on the opposite wall, the amount of daylight in the room can be greatly increased.
• This also gives the illusion that the room is wider than it is.

Apart from these commonly used daylighting elements, many innovations have been made and implied. Some of them are-

6. Prismatic glazing

• This method uses refraction of light over reflection.
• It can be used with windows or skylights.
• Sunlight is refracted away from the inside of the room to eliminate glare while allowing daylight to propagate below.

7. Light Shelves

• They alter the distribution of sunlight in a room.
• They help in getting daylight to the further back of rooms by reflecting light on the ceiling.
• This ensures uniform lighting.

8. Light pipes

• A derivation of roof lighting, daylight is directed using reflective tubes.
• This form of lighting is useful in bringing light to areas which cannot be naturally lit.
• These pipes can also serve the purpose of ventilation, but have the disadvantage of taking up useful space.

9. Solar shading

Though natural light is essential for any building, it also becomes important to ensure it is used effectively without causing damage in the long run. The sun’s UV rays can fade and damage the natural textures and surfaces in a building. Solar shading helps diffuse the light and also aids in reducing heat gain and to cut down on glare.

Solar shading can be effectively reduced by-

1.      External shading

2.      Internal shading

10. External shading

• External shading is considered to be more effective as it controls the heat gain before it enters the building.
• However, it is more vulnerable and difficult to maintain.
• We must ensure that the materials used can withstand the climate of the site.
• It is achieved by the use of overhangs, canopies, louvers, etc.

12. Internal shading

• This form of shading might be less efficient, as the heat has already entered the building and will be more difficult to extract.
• However, it is less vulnerable and easier to maintain and clean.
• Some examples are curtains and blinds, which also help in controlling glare.

Daylighting is definitely one of the best ways to illuminate a building given that the correct method, elements and precautions are followed to make it durable and sustainable. When paired with the complementing artificial lights, the building will glow.

Here’s an example of a building that uses daylighting techniques extensively to naturally illuminate the interiors

Portcullis House

• It was built by architect Michael Hopkins as an office building in Westminster, London.
• At ground level, the building has a courtyard with a vaulted glazed roof.
• The windows at the members office have light shelves that bounce light onto the white concrete arched ceiling into the interior of the room.
• Clerestories above the bookcases allow light to escape from the interior of the room to the internal corridors which would otherwise have to be artificially lit.