Whether you’re upgrading the lighting in your home or you’re a lighting designer specifying fixtures for a commercial new construction project, you’re probably concerned about the same things. Apart from staying within budget, you’re worried about having adequate lighting. Like most, you don’t want your home flooded with light but you also don’t want to be left with inadequate light. The balance is in the planning. First, you’ll need to know the square footage of the area you want to light. Once you calculate for adequate lighting, you can use proper dimming controls to match cozier moods.
Step 1: Properly determine the room size
Bigger rooms require more light to properly illuminate the full space. So, to determine how much light you need, you first need to know the size of the space you’re lighting.
Square footage (w*l = Area)
- Measure the length of one wall.
- Measure the width of one wall.
- Multiply the width by the length.
Area for circular rooms (πr2 = Area)
- Measure from the center of the room to an outside wall.
- Multiply that measurement by Pi (3.14).
- Square the new number
If you’ve got some sort of crazy-shaped home, then you may have the break out the old high school textbooks and do some geometry.
Step 2: Map the space for how you’ll use it
Now, it’s helpful to plot out the room on a piece of paper. Draw in furniture and any big obstructions. Planning lighting around objects is a more exact way to make sure that you have the right amount of light you want. Like Goldilocks, you don’t want too much, or too little.
Having enough light isn’t the only thing to consider. Color and quality of light are also big considerations. Take note of where you spend the most time, and what you do in that space. Perhaps you have a favorite recliner where you take naps. Maybe you have a work area that needs to be well-lit. If you are relaxing, keep the kelvin of the light down (2700K – 3000K). Meaning, you will want a warm orange-colored light that sits around 2,700 degrees Kelvin. If you need to work, a high CRI bulb with a Kelvin rating of around (4100K – 5000K) is great. If you need more information on any of this industry lingo, this guide on architectural lighting fixture specifications can help.
Step 3: Calculate lumens based on space
Now comes the fun part. For every square foot of space you have, you assign a set number of lumens to it:
- A square foot of floor needs 20 lumens.
- A table or raised surface needs 30 lumens.
- A workspace needs 50 lumens.
Lumens are a scientific estimate of ambient light coming from a lighting source. Most lighting products list their lumen output on their packaging or specification sheets.
Please note as a warning, large ceilings require the consideration of foot candles. If you have an extremely unique area to light, it may be better to contact Alcon Lighting or hire a professional lighting designer.
