Lighting design principles
This sheet provides some methods widely used by lighting professionals, to design a successful “ensemble”.
1-The lighting criteria
Our lighting environment should not be uniform: human attention is attracted to the light, and our gaze instinctively turns to the best lit areas of our surroundings. A successful lighting should therefore highlight the parts which one wishes to emphasise, such as for instance the places to which you want to attract attention, and the areas of interest to which people should gather: a dining room table, the coffee table of a living room, a library etc.
We are also very sensitive to the type of light that surrounds us. Our mood is influenced by its colour and intensity:
- A cold, direct lighting suggests work, energy, activity;
- A warm, attenuated light inspires relaxation, intimacy, comfort.
Some activities are usually associated to a specific light intensity. A working table should enjoy bright lighting, while watching TV will call for a light-toned atmosphere. As a consequence, the characteristics and layout of fixtures that equip each room of a house must be selected according to 3 criteria:
- The desired ambient light intensity;
- The light colour (bright or soft);
- The distribution of lighting to highlight the decoration of each room.
To simplify the thinking, it helps to distinguish:
- The diffuse lighting, which bathes the entire room;
- The direct lighting that one chooses to concentrate on areas of interest.
2-Diffuse lighting
Diffuse lighting provides the entire room with an overall luminosity. This component has two main characteristics: its intensity and its colour.
The intensity of the illumination of a surface is measured in lux. The higher the number, the better lit the surface appears (read our technical page for more explanations). The table below shows some examples of intensity measured in daily life.
| Situation | Lighting (lux) |
|---|---|
| Moonlight, clear night | 0.25 |
| Candle lit Restaurant | 20 |
| Normally lit living room | 100 |
| Very bright Office | 400 |
| Sunny Day in the shade | 10 000 |
| Sunny day surface in full sun | 100 000 |
The following table shows the intensity and colours usually chosen professionals when choosing the lighting for a house:
| Light intensity | Room & Atmosphere desired | Color |
|---|---|---|
| 25-50 Lux | Lounge, dining room, adult room, subdued ambience, romantic | Hot |
| 100-150 Lux | Lounge, dining room, kitchen, adult room, office. Restful and convivial atmosphere | Hot |
| 200-250 Lux | Working atmosphere (office, library), children rooms (nursery, playroom) | White |
| 350-500 Lux | “Technical” atmosphere: areas of high activity (office, workshop) and circulation (hallways, entrance) | White |
3-Directed Lighting
The directed lighting highlights certain areas of interest in the room: in a living room, these points of interest can be materialised by certain decorative objects placed or hung on the wall, by certain furniture (table, desk, coffee table). In a dining room or kitchen, these areas are usually the table and work tops. Sometimes the points of interest are only architectural, for example an apparent framing or a decorative interior staircase. Lighting specialists generally estimate that an area of interest should be 3 to 5 times more illuminated than the rest of the room. The values (in lux) shown above should therefore be multiplied by 3 to 5. Of course, a more intense directed lighting of the areas of interest should be compensated by a lower level of diffuse lighting – in practice, 200 lux or less. The directed lighting is obtained with luminaires capable of concentrating the light produced – for example equipped with a reflector (for instance spotlights), or desk lamps that concentrate the light downwards.
Conclusion
In summary, the following two design principles should be followed:
- A relaxing atmosphere is better appreciated if it is bathed by a diffuse illumination of 50 to 150 lux with preferably a warm tone which can be easily obtained by using luminaires with filters, or luminaires equipped with dimmers, or bulbs of the right colour. Areas of interest should be illuminated 3 to 5 times more – typically 150 to 500 lux – using directional luminaires such as spot bulbs with reflectors, wall or table lamps, and often with a whiter light.
- An active atmosphere should have a lighting between 150 and 500 lux, and a colder light tone – obtained for example with light-shaded luminaires and bulbs with a warm white tone of 3500° K minimum (for more information, see our guide on the technical terms).
We will see in the more detailed pages of our guide, that the current trends are to provide some tuning for intensity, temperature and even colour, to change these atmospheres on demand or automatically.
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You can find further guidance in the following page:
- Our advices to dimension your lighting and choose your fixtures: the principles of lighting design.
- Which types of bulbs you should choose, from all the technologies now on the market - fluo-compact, LEDs etc: what you need to know about bulb technologies.
- How you should choose the LED you need, depending on your room and your expectations in terms of lighting (there is more to it than what you can read on most bulb packages): our guide to choosing LED bulbs.
- Explanation of what the various lighting units mean, and how to use them: how to speak the jargon, with lux, lumen and candela!.
- Use our calculators to size your lighting according to its purpose: our lighting calculators.
- Find your way in the jungle of the various European bulb types: our simple guide to the various bulb models.
- Read our advice on why you could consider connected lighting, and how you can jump on the train without the headaches: starting with connected lighting.
You can also find below our advice to choose and install the various types of lighting you can find in our catalogue:
- suspensions, chandeliers and pendants
- Table and desk lamps
- Wall lights
- Lighting beacons for circulation areas (indoor or outdoor)
