Basic Lighting Design Terminology and Illumination Fundamentals

Every design process requires effective communication. This will only happen when all parties involved understand the key technical terms and concepts used by each. For lighting on any given project, lighting designers, engineers, contractors, and interior decorators must all possess a basic knowledge of the terms that describe the qualities of light, lighting equipment, and equipment placement. Here's a rundown on some of the more important architectural lighting design terminologies.

Basic Types of Lighting

Basic Types of Lighting

Lighting designers use three basic types of lighting on most projects - General, Task, and Accent.

General Lighting - Also known as ambient lighting, general lighting provides an area with an overall level of brightness and illumination. It allows people to see well and move about safely. Homeowners typically use ceiling or wall-mounted fixtures, chandeliers, and recessed or track lights for their general lighting needs. Lighting designers on commercial projects will often incorporate sunlight into their lighting plan, as well.

Task Lighting - Task lighting helps people perform specific tasks. Hospital operating rooms, for example, require extremely bright light. Most people use task lighting without giving much thought for activities like cooking, sewing, and reading. Task lighting should be bright enough to prevent eye strain and free of distracting glare or shadows.

Accent Lighting - Accent lighting creates visual interest in a room or specific object. In a museum, lighting designers employ accent lighting to highlight sculptures, paintings, and artifacts.

A business might use accent lighting on product displays, to light their name on a wall, or just to add ambience to a space. In the home, accent lighting plays a role as part of decorating schemes indoors, or for landscaping purposes, outdoors.

To be effective, accent lighting should deliver at least three times as much light as the general lighting around it. Spot, track, and under-cabinet lights are some of the more common types of equipment used to provide accent lighting.

Qualities of Light

Qualities of Light

Lighting designers use a range of terms to describe the properties of light. The colour, colour temperature, and intensity of lighting on every project must be conveyed accurately to all relevant parties.

Colour - The visible spectrum of light consists of seven colours - Violet, Indigo, Blue, Green, Yellow, Orange, and Red. The human eye, however, only sees red, blue, and green. The human mind then blends these three, as needed, to create the entire colour palette.

Colour Temperature - Measured on the Kelvin scale using values between 1000K, and 10,000K, colour temperature describes a light's softness (or hardness). The lower the rating, the warmer the light. Most soft white bulbs have a rating of 2,700K to 3,000K. Temperatures between 3100K and 4500K are considered "bright-white" or "cool white." Bulbs with these temperatures have a slight blue tint and give off a more neutral white light. Light bulbs with colour temperatures of 4500K and above emit a blue-white light similar to daylight.

Intensity - Designers use a light's Lux value to indicate intensity. Based on the fundamental intensity unit known as the Lumen, the Lux represents Lumens per square metres.


Lighting Placement

The three most common forms of architectural lighting are soffit, cove, and valance. Soffit lighting radiates downward and covers a wall with light from a cornice or soffit near the ceiling.

Positioned on a shelf, a ledge, or recessed high up on a wall, cove lights get pointed upward and light the ceiling or upper wall. Usually located above a window or high on the wall, valance lighting sends light in an upward and downward direction simultaneously.

The technique of bouncing light off walls and ceilings is known as indirect lighting and used by lighting professionals to improve the ambience and minimize glare and shadows.

Types of Light Fixtures

Light Fixtures

Fixtures used in Architectural lighting projects come in a wide variety of styles. Some of the most common include chandeliers, wall sconces, ceiling, recessed, track, under-cabinet, pendant, and portable lights.

  • Chandeliers hang from the ceiling and provide ambient lighting. They're usually located over a table and direct their light upward. Chandeliers add decorative style to a room.

  • Wall Sconces may provide both task and ambient lighting. Mounted on the wall, sconces can direct light upwards or downwards. Like chandeliers, sconces often add style, as well as functionality, to a room.

  • Ceiling lights have been used in homes and offices for over one-hundred years. The typical ceiling light takes between one and four bulbs, has a glass or plastic shade, and gets mounted on the ceiling in the centre of a room.

  • Recessed lights have their opening flush with the ceiling. They provide a relatively narrow band of light in one direction; and are used for ambient, task or accent lighting.

  • Track lighting consists of a linear housing (track), and several lights along the track. Each light can be positioned anywhere along a track, as well as pointed at various downward angles. Track lighting provides both task or accent lighting.

  • Under-cabinet lights come in a range of styles, the most popular being puck-shaped. Usually used under kitchen cabinets, depending on their colour warmth and brightness, these lights deliver both task and ambient lighting.

  • Pendant lights extend down from the ceiling and direct their light on a table, desk, or kitchen counter. Designers use pendants to add decorative style, as well as provide ambient or task lighting.

  • Portable lighting includes floor, desk, and table lamps. Made in a wide range of styles and sizes, these types of lamps are extremely versatile and used for both ambient and task lighting.

Lighting professionals use many other terms throughout the course of a project. But, these are some of the more common illumination fundamentals and terminologies used in most.