How much light a surface reflects back into the room, as opposed to absorbing, will affect how far daylight effectively penetrates into a room.

To maximize daylight penetration into a room, ensure that surfaces have at least the following reflectance values:

• Ceilings: 80% (.8)
• Walls: 50% - 70% (.5 - .8)
• Floors: 20% - 40% (.2 - .4)
• Furniture: 25% - 45% (.25 - .45)

Reflectances for paints and other surfaces are often available from manufacturers.

Here are some typical reflectance values:

• New white paint: 75%
• Old white paint: 55%
• Glass windows: 70%
• White portland cement (new): 70% - 80%
• White portland cement (weathered): 40% - 60%